CN100433245C - Laser crystallization apparatus and laser crystallization method - Google Patents

Abstract

A laser crystallization apparatus, which enables an observation of a high spatial resolution with several mum and a high temporal resolution with several nanoseconds, comprising a crystallization optical system to irradiate a laser light to a thin film provided on a substrate and to melt and crystallize the thin film, the laser crystallization apparatus comprises an illumination light source disposed out of an optical path of the laser light and emitting an illumination light for observation to illuminate the thin film, an illumination optical system comprising an annular optical element which has the optical path of the laser light in the center and which leads the illumination light from the illumination light source to the thin film along the optical path, and an observation optical system which displays a magnified image of the substrate including the thin film.

Description

Laser crystallization apparatus and laser crystal method

Technical field

The present invention relates to a kind of with laser radiation to as the crystallizer on the film of semiconductor film and a kind of method for crystallising, and relate in particular to a kind of laser crystallization apparatus and laser crystal method, wherein can observe the fusing and the crystallization process of semiconductor film with enlarged image in real time.

Background technology

Researched and developed a kind of laser crystallization technology, wherein for example the high energy short-pulse laser is used for fusing and crystal semiconductor film, and the non-single crystal thin film of feasible for example amorphous or polycrystal semiconductor film becomes the crystalline membrane that comprises the zone with big crystal grain.For example, this technology is used for the crystallization as the non-single crystal semiconductor film of the thin-film transistor of display device (as liquid crystal display device and organic elctroluminescent device).

In this class laser crystallization technology, attentiveness concentrates on phase modulated quasi-molecule laser annealing (PMELA) technology that irradiation is used for the phase modulated excimer laser of crystallization.The PMELA technology forms uniform excimer laser the laser with predetermined light distribution.By means of phase modulation component, such as phase shifter for example, this laser of phase modulated and make it have the negative peak light distribution.By the crystal optics system with laser radiation on semiconductor film, for example, irradiation is formed on the amorphous silicon or polysilicon membrane on the large-area glass substrate, so that make this semiconductor film fusing and crystallization, has the semiconductor film of big crystal grain with formation.According to the PMELA technology of recent exploitation, the zone of fusing and the about several mm square of crystallization in once irradiating has high-quality crystal silicon film so that form, and it has the relatively all even big crystal grain from a few μ m to about 10 μ m sizes.Its correlative detail for example is disclosed in the paper periodical Vol.J85-C of electronics, information and communication enineer association, No.8, pp.624-629, in 2002, in " the new growing method of the big crystal grain of the amplitude of silicon thin film and phase modulated excimer laser fusing renovation process-2-D Position Control " that Kohki Inoue, Mitsuru Nakata, MasakiyoMatsumura are delivered.

In present PMELA technology, excimer laser power is changed to 10% from 5% in actual use., compare with the stability of excimer laser, the fininsh allowance that forms the crystal silicon film with predetermined quality is very narrow.Therefore, in order to make the EPMLA skilled industryization, need to increase finish allowance, so that form crystal silicon film with higher and stabilised quality.Thus, need be after laser radiation and then, by image etc. with high instantaneous resolution with the high spatial resolution of a few μ m and/or nanosecond (below be called nsec) level, the variation of observing or measuring silicon thin film in real time, wherein melted silicon film and make its crystallization subsequently in the zonule.

In Japanese Patent Application Publication No.2001-257176, disclosed a kind of method of degree of crystallinity of the silicon thin film that is used to estimate laser annealing.This method comprises: apply observation light to the silicon thin film in crystallization just, use spectrometer that reverberation is carried out for example Raman (Raman) spectroscopic assay; And estimate the degree of crystallinity of polysilicon membrane after crystallization thus.

In the ELA technology of carry out phase modulation not, in the J. Applied Physics, Vo.87, No.1, pp.36-43,2000, M.Hatano, S.Moon, M.Lee, reported an experiment embodiment in K.Suzuki and C.Grigoropoulos " Excimerlaser-induced temperature field in melting and resolidification of silicon thin films ", wherein come the thermal characteristics of the silicon thin film of in-site measurement fusing and crystallization by field measurement apparatus.This report relates to the thermal characteristics of measuring fusing and crystal silicon film with the high instantaneous resolution of nanosecond.More particularly, will be applied to the zone of fusing and crystallization as He-Ne (He-Ne) laser (wavelength is 633nm and 1520nm) of the detection light that is used to observe from upper angled ground.Indium gallium arsenide photoelectric detector by high-speed response and/or silicon pn photodiode detect reflection and/or the transmitted light from fusing and crystal region, so that the thermal characteristics of measurement silicon thin film.

In addition, in Japanese Patent Application Publication No.2002-176009, disclosed the field observation method of shining crystal laser simultaneously and observing light.In this patent, the object lens with hole are used for the irradiation of crystal laser and illumination and the detection of observing light.Crystal laser is not by the excimer laser of phase modulated, and shines on the just processed film by the hole that is provided with on the object lens.In annealing process, detected by object lens by the just processed light that film reflected, so that the scene of the reflectivity, Raman spectrum etc. of sample surface for example of measuring changes with hole.That is to say, carry out the degree of crystallinity assessment according to the physical characteristic value of crystal region.

The problem that the large-scale production line that utilizes ELA equipment as used herein to carry out crystallization is given existing in the industrialization comprises: the raising of the output of crystallization process, and because the unsteadiness of irradiating laser, by monitor the stability of the quality control that crystallization process carries out by operating personnel, the loss on intensity such as for example pulse and/or fluctuation.At this, the exposure period of laser pulse that is used for crystallization is very short, for example about 25 to 30 nanoseconds.In order to address these problems, need be after laser radiation, by image with the high instantaneous resolution of the high spatial resolution of a few μ m and nanosecond on-the-spot and Real Time Observation or measure the change state or the crystal region of silicon thin film, wherein silicon thin film in the zonule with the subsequent crystallisation also of fusing in about 10 to the cycle of hundreds of nanosecond.

The method of above-mentioned Japanese Patent Application Publication No.2001-257176 is not suitable for the purpose by the crystallization of image viewing silicon thin film.The method of Japanese Patent Application Publication No.2002-176009 is suitable for observing by image, but it is unsuitable for observing silicon thin film from being melted to the variation of crystallization by image with high instantaneous resolution and/or high spatial resolution.

People's such as M.Hatano method has high-resolution timely, but is unsuitable for satisfying simultaneously the image observation system of a few μ m or the high instantaneous resolution of high spatial resolution still less and several nanoseconds.

The inventor has been found that the better quality for the crystal semiconductor film, need image observation system be installed in laser crystallization apparatus (for example excimer laser crystallization (ELA) equipment), promptly is used to the optical system of observing.In this system, semiconductor film is changed to crystalline state from molten state, and with the high spatial resolution of a few μ m and the high instantaneous resolution of nanosecond this film is carried out Real Time Observation by image, or observe in during the crystallization of after laser fusion or fusing, carrying out immediately.

Therefore, the inventor after deliberation can carry out image viewing the microexamination system incorporate in the ELA system observe so that can realize scene (in real time).For the microexamination optical system being incorporated in the optical system of ELA equipment, preferably use wherein the optical system of the excimer laser (ultraviolet light) that is used for crystallization and the illumination light (visible light) that is used to observe being carried out aberration correction.The microexamination optical system can on-the-spot (in real time) be observed the fusing also semiconductor film after the crystallization or the image of crystal region.

Address the above problem and satisfy the demand and additionally cause following problem.In ELA equipment, particularly in porjection type phase modulated (PM) the ELA equipment that uses phase shifter, high-resolution (a few μ m) is preferred.Suppose because of production efficiency the actual lens that use in the PMELA equipment are used for highlight strength, high power (high duty) and big zone.Particularly, will preferably approximately be 1J/cm by the laser intensity on the substrate of crystallization ²Has the excimer laser of wide spectral bandwidth (0.5nm) in order to obtain high light intensity, to be different to be used for the employed laser of calibrator (aligner) that large scale integrated circuit is produced, using.Because high energy laser, according to heat resistance, it is inappropriate comprising coating (pasted) and stacked (laminated) lens microlens of visible light (as be applicable to).In addition, the excimer laser that will use can be that for example wavelength is respectively KrF (KrF) or the chlorination xenon (XeCl) of 248nm and 308nm.When considering these Wavelength of Laser, the preferred lens material that uses is limited to UV level synthetic quartz or calcirm-fluoride (CaF ₂), and this has reduced the degree of freedom of lens design.In addition, for example, must carry out aberration correction, as ultraviolet aberration and distorton aberration as being used for to dwindle or identical size and the mask pattern of phase shifter is transferred to lens (group) on the substrate for what use in the PMELA equipment with the high-resolution of about a few μ m.

When in this single optical system, using excimer laser and microexamination visible light, must in comprising two wavelength region may of ultraviolet light and visible light, carry out aberration correction, and this is a very difficult problem.Promptly allow to correcting chromatic aberration, also must increase the quantity of lens, and then increase the absorption of lens light.This has reduced the laser intensity that arrives substrate, and this has run counter to the demand of the high light intensity that obtains to be suitable for crystallization.

Another problem is: be suitable for having the crystal optics system of the excimer laser of above-mentioned performance, reduced the resolution of visible light when it transmits visible light.Particularly, resolution and light wavelength are proportional, make and for example have about excimer laser (wavelength: 248nm at visible light (wavelength: 480nm to 600nm), 308nm) under the situation of the twice of wavelength, the resolution of 2 μ m is reduced to the resolution of 4 μ m in visible light, and this resolution be before the twice of resolution.Therefore, can not obtain to observe or measure the necessary 1 μ m resolution of crystal region image of a few μ m.

That is to say that the optical system that can be suitable for this needs need stably be used at least two kinds of different wave lengths: be used for the excimer laser (for example, wavelength is 248nm) of crystallization, have high light intensity and (for example on substrate, be 1J/cm ²Or higher), big irradiation area (for example, 5.5mm ²Or bigger) and high power (duty)

(for example, 100Hz or higher laser operations frequency); And the illumination light that is used to observe, for example be visible light (for example, wavelength in 480nm to the 650nm scope).

For such example, be used for micro-high-resolution UV laser focusing mirror, for example the lens of the KVH20-8 model of ShowaOptronics can be from commercial acquisition, in these lens, correcting chromatic aberration simultaneously in ultraviolet light and wavelength of visible light scope.Condenser is designed to be and uses an optical system to utilize excimer laser to handle zonule (0.5mm for example ²Or littler) and observe with visible light.The zonule of being undertaken by optical lens is handled and is for example tended to excise part wiring in the integrated circuit by irradiating laser.Described lens fully satisfy the demand of spatial resolution (1 μ m), but can not operate with above-mentioned high light intensity, big irradiation area and high power.

In addition, need to use the high instantaneous resolution of utmost point short time (nanosecond) to observe, so that carry out Real Time Observation by being arranged on the semiconductor film image that is in fusing and crystalline state on the substrate.Need meet the highlight illumination light that observation post that the short time observes uses.If visible light is carried out the illumination light that observation post uses by a large amount of optical lenses as above-mentioned, then not only cause the problem of light loss, and cause problem the adverse effect of the imaging characteristic of original ultraviolet light.

An object of the present invention is to provide a kind of laser crystallization apparatus and laser crystal method, wherein can be with a few μ m or high spatial resolution still less and high instantaneous resolution, just observe or measure image in real time, or immediately this image is being observed or measured thereafter with a few μ m zone on the semiconductor film of fusing of hundreds of nanosecond and crystallization.

Summary of the invention

Problem described above and the thing of being paid close attention to can be solved by the laser crystallization apparatus and the laser crystal method of following elaboration.

According to an aspect of the present invention, a kind of laser crystallization apparatus is provided, comprise the crystal optics system, be used for laser radiation to the film that is arranged on the substrate and fusing and this film of crystallization, described laser crystallization apparatus comprises: lighting source, be arranged on outside the optical path of laser, and launch the illumination light emission that is used to observe, to illuminate described film; Lamp optical system comprises the optical ring element, and this optical ring element has the optical path of the laser that is positioned at the center and illumination light is guided on the film along described optical path from lighting source; And viewing optical system, be used for showing the image of the substrate comprise film with enlarged image.

According to a further aspect in the invention, provide a kind of laser crystal method, comprising: emission laser; With laser radiation to the film that is arranged on the substrate, with the fusing and crystalline membrane; Utilize and observe illumination light illuminates laser radiation along the laser optics path zone, wherein illumination light is directed to film via reflection-type optical ring element, described optical ring element is with the coaxial setting of the optical path of laser and pass laser, and wherein the optical path of laser is arranged on the center; Amplification is observed illumination light and it is imaged as at least one image of the film that is in fusing or crystalline state through the reflection of film reflection; And pick up enlarged image.

Other advantages of the present invention will be set forth in the following description, and partly become clear according to this explanation, maybe can be recognized by putting into practice the present invention.By hereinafter specific means of pointing out and combination thereof can realize and obtain advantage of the present invention.

Description of drawings

Be included in the specification and constitute the description of drawings embodiments of the invention of a specification part, and principle of the present invention is described with the detailed description of above provide in a word bright and the embodiment that hereinafter provides.

Fig. 1 is the system configuration schematic diagram of the explanation embodiment of the invention;

Fig. 2 shows to observe the schematic diagram that lamp optical system is used the example of structure of polarization laser among Fig. 1;

Fig. 3 is the structural representation of explanation as the structure of the striped pipe of photoelectric detector example among Fig. 1;

Fig. 4 A to 4E is the schematic diagram that shows the timing diagram example of the fusing of the semiconductor film that is used for observing equipment shown in Fig. 1 and crystallization, and wherein Fig. 4 A shows the timing of crystallization pulse laser EL; Fig. 4 B shows the timing of the triggering signal P2 that is used to the scanning voltage SV that observes the triggering signal P1 of illumination light OL and be used for the striped pipe; Fig. 4 C shows the timing of observing illumination light OL; Fig. 4 D shows the timing of the scanning voltage SV of striped pipe 42; And accompanying drawing 4E shows the timing of the triggering signal P3 of image device;

Fig. 5 is the schematic diagram of the image that shows on the display unit in the key diagram 1;

Fig. 6 A, 6B show an example according to the observed result of the crystallization process of equipment shown in Fig. 1, wherein Fig. 6 A shows the light distribution of the excimer laser of irradiation, and Fig. 6 B shows the micro-image of the observed result of crystallization process in the display light irradiation area; With

Fig. 7 A, 7B show another example of the observed result of crystallization process, and wherein Fig. 7 A shows the light distribution of the excimer laser of irradiation, and Fig. 7 B shows the micro-image of the observed result of crystallization process in the display light irradiation area.

Embodiment

With reference to the description of drawings embodiments of the invention.Be included in the specification and constitute the accompanying drawing of the description of drawings embodiment of the invention of a specification part, and principle of the present invention is described with the detailed description of above provide in a word bright and the embodiment that hereinafter provides.In institute's drawings attached, represent corresponding part with identical reference number.These embodiment only are some examples, and do not depart from the scope of the present invention and smart situation of dashing under can carry out various changes and modification.

In ELA equipment, for Real Time Observation or measure the image in a few μ m crystallization processs zone, wherein in described zone with hundreds of nanosecond fusing and crystal semiconductor film, must meet from excimer laser crystallization optical system that is used for crystallization and the demand that is used for the microexamination system of image viewing.That is, must satisfy on the high-resolution of a few μ m in the ultraviolet light and the substrate approximately 1J/cm ²High light intensity, these are requirements of crystal optics system, and the high instantaneous resolution that satisfies high-resolution and the nanosecond of a few μ m in the visible light, these are requirements of microexamination system.

In order to address these problems, to be used for the observation lamp optical system of image viewing and microexamination system and to be incorporated into laser crystallization apparatus independently with the crystal optics system.The microexamination system comprises the microexamination optical system that the high instantaneous resolution of the high-resolution that can utilize a few μ m and nanosecond is observed.Following with reference to the structure of description of drawings present embodiment and the example of application.

Fig. 1 is the schematic diagram that shows the general survey of present embodiment laser crystallization apparatus 1.This equipment is laser crystallization apparatus 1, is used for throwing the image of phase modulation component and comprising reflection-type microexamination system with minification.In addition, this equipment has on the image viewing result's of microexamination system basis, just proofreaies and correct the function in the displacement of the substrate 26 of crystallization.

As shown in Figure 1, laser crystallization apparatus 1 comprises: crystal optics system 2, be used for the presumptive area place of laser radiation on substrate 26, and so that the semiconductor film that is arranged on the substrate 26 melts and crystallization, be used for crystallization; Reflection-type is observed lamp optical system 3, is used to apply illumination light, to observe the fusing and the crystalline portion of semiconductor film; Reflection-type microexamination optical system 4 is used for by fusing and the crystallization to take place hundreds of nanosecond in image measurement and a few μ m of the observation semiconductor film zone; And level driver 60.Present embodiment is characterised in that, because the imaging optical system 25 in the crystal optics system 2 has long-focus (50mm to 70mm), so be provided for the independently observation lamp optical system 3 of high intensity visible and reflection-type microexamination optical system 4 independently in the space between imaging optical system 25 and substrate 26 coaxially.That is, observe lamp optical system 3 and be independent of crystal optics system 2 and not mutual interference mutually with microexamination optical system 4.

Present embodiment relates to laser crystallization apparatus and laser crystal method, it is characterized in that: crystal laser, for example excimer pulsed laser shines for example about 4mm of the semiconductor film that is used for crystallization that is provided with on the substrate 26 ²To 25mm ²The zone in so that realize fusing, curing and crystallization, make to utilize and observe in the light-struck μ m level of the illumination zone and state that occur over just in several 10 nanosecond cycles changes, be presented in real time with image to monitor on the screen 45c.

The microexamination system features of the image that changes with hundreds of nanosecond ultrahigh speed in the above-mentioned very small region of picking up a few μ m is: crystal optics system 2 is formed on the central shaft, and optical ring element 3A is set, its optical path reflection-type on every side that constitutes crystal optics system 2 is observed lamp optical system 3 and microexamination optical system 4, makes optical ring element 3A not stop the optical path of laser.This can realize observing or monitoring with the high spatial resolution of the high spatial resolution of a few μ m and nanosecond.The modified-image that only takes place with hundreds of nanosecond in irradiation has the crystallization process zone of crystal laser is picked up by microexamination optical system 4, and is stored in memory unit 45b, for example in the memory.Under observer's required condition for example with required speed, on monitor display screen 45c with rest image or video pictures after crystallization or show the variation of state in the crystallization process zone of a few μ m in real time.At this, the crystallization process zone refers to shine has crystal laser and from just being changed to solidification process up to the zone of finishing crystallization in fusion process.

At first, with reference to Fig. 1 crystal optics system 2 is described.Crystal optics system 2 comprises: LASER Light Source 21, beam expander 22, homogenizer 23, phase modulation component 24 (as phase shifter), imaging optical system 25 and the substrate fixed station 27 that substrate 26 is guided to the precalculated position.By the laser of beam expander 22 expansions from LASER Light Source 21, and the light intensity in the cross section is arrived phase modulation component with laser radiation, as phase shifter 24 subsequently by homogenizer 23 homogenizing.The excimer laser by phase shifter 24 has been for to have had the light modulated of required light distribution (for example negative peak light distribution), and is irradiated on the substrate 26 by imaging optical system 25 (as the quasi-molecule imaging optical system).

LASER Light Source 21 for example about 25 to 30 nanoseconds of output are wide, have for example 1J/cm ²Energy pulses laser, it is enough to melt the semiconductor film that is arranged on the substrate 26, and this semiconductor film is not a monocrystalline, for example is amorphous or polycrystal semiconductor film.Described laser is preferably the KrF excimer laser with 248nm.Other irradiates light comprises XeCl excimer laser, argon fluoride (ArF) excimer laser, argon (Ar) laser, YAG laser, ion beam, electron beam and xenon (Xe) photoflash lamp.For example, excimer light source 21 is the impulse hunting type, and for example has the frequency of oscillation in 100Hz to the 300Hz scope, and the pulse duration in the half breadth scope of 20 nanoseconds nanosecond to 100 for example.In the present embodiment, using half breadth is the KrF excimer laser of 25 nanoseconds.In addition, the light energy that shines the KrF excimer laser on the substrate 26 is 1J/cm ²Frequency of oscillation is for example 100Hz, and utilize the zone of excimer laser irradiation to be for example 2mm * 2mm size, make stage irradiation excimer laser, move substrate 26 by substrate control desk 27 with the stride of for example 2mm simultaneously, and the translational speed of substrate 26 is 200mm/sec like this.

Beam expander 22 expansion incoming laser beams, and comprise concavees lens 22a that is used for extensible beam and the convex lens 22b that is used to form collimated light beam, as shown in Figure 1.Homogenizer 23 is determined the sectional dimensions of incoming laser beam on the X-Y direction, and in the shape of determining the homogenizing beam intensity.For example, the cylindrical lens of a plurality of directions Xs is set along the Y direction, be arranged on a plurality of luminous fluxes on the Y direction with formation, each luminous flux is redistributing on the Y direction by the condenser of directions X, similarly, along the cylindrical lens of a plurality of Y directions that are provided with on the directions X, be arranged on a plurality of luminous fluxes on the directions X with formation, and each luminous flux redistributes on directions X by the condenser of Y direction.That is, as shown in Figure 1, homogenizer 23 comprises first homogenizer with first fly's eye (fly-eye) lens 23a and first condenser 23b, and second homogenizer that comprises the second fly lens 23c and the second condenser 23d.First homogenizer gets the laser incidence angle evenly in phase shifter 24 adjusted, and second homogenizer is with the position laser intensity homogenizing in cross section on the phase shifter 24.Therefore,, the KrF excimer laser is adjusted to the illumination light that cross section has required angular separation and uniform beam intensity by using homogenizer 23, and this KrF excimer laser irradiation phase shifter 24.

Phase shifter 24 is an example of phase modulation component, and is the quartz glass substrate that for example has step.Laser causes diffraction and interference at the edge of step, so that the cycle spatial distribution of laser intensity to be provided, and for example provides 180 ° phase difference on the right at edge and the left side.Have the phase place of phase shifter 24 modulating the incident lights of 180 ° of phase differences on the right with on the left side, have the light beam of symmetrical negative peak light distribution with formation.Step (thickness difference) d can draw from d=λ/2 (n-1), and wherein λ is a Wavelength of Laser, and n is the refractive index of the lens-substrate of phase shifter.According to this equation, for example can generate phase shifter 24 by forming step d on corresponding to the quartz glass substrate of predetermined phase difference.Can pass through the step on selectively etching and FIB (focused ion beam) the technology formation quartz glass substrate.For example, when the refractive index of quartz substrate was 1.46, the wavelength of XeCl excimer laser was 308nm, made that it is 334.8nm that the step of 180 ° of phase differences is provided.Phase shifter 24 has in this manner the step that forms, and described mode is the phase modulated incident beam forming the mode of negative peak light distribution, and with the phase transition half-wavelength of excimer laser.Therefore, be radiated at the light distribution that laser on the semiconductor film has the pattern of negative peak, wherein the part of corresponding phase conversion portion is in the minimum light strength.According to this method, under the situation of not using the normally used metal pattern that is used to cover excimer laser in the additive method, obtain required light beam light distribution.

The laser by phase shifter 24 is imaged on the substrate 26 with predetermined light distribution by differing the quasi-molecule imaging optical system 25 that is corrected, and described substrate is positioned at phase shifter 24 and has on the position of the relation of gripping altogether.Imaging optical system 25 comprises set of lenses, and it comprises for example a plurality of calcirm-fluoride (CaF ₂) lens and/or synthetic quartz lens.Imaging optical system 25 is a long-focus lens, have reduction gear ratio as 1/5,0.13 N.A.2 μ m resolution, ± performance of the depth of focus of 10 μ m and the focal length of 50mm to 70mm.

Imaging optical system 25 is arranged on optics with phase shifter 24 and substrate 26 and grips on the position altogether.In other words, substrate 26 is set at the position of gripping altogether with phase shifter 24 (imaging surface of imaging optical system) optics.Imaging optical system 25 comprises the aperture that is arranged between the lens.

About the substrate 26 that is used for crystallization, just processed film, for example semiconductor film is formed on the substrate via dielectric film usually, is formed with the dielectric film as coverlay on described substrate.As just processed semiconductor film, can use for example amorphous silicon membrane, polysilicon membrane, sputtered silicon film, germanium silicide film, dehydrogenation amorphous silicon membrane.As substrate, can use glass substrate for example, plastic, such as the Semiconductor substrate (wafer) of silicon.For the substrate 26 that uses in the present embodiment, on substrate, form the dehydrogenation amorphous silicon to such an extent that have preset thickness, for example thickness of 50nm.Substrate 26 removably is fixed on the substrate fixed station 27, and described fixed station can be fixed on substrate on the precalculated position and can move along X, Y and Z direction.

As mentioned above, laser crystallization apparatus 1 is the porjection type crystallizer, wherein crystal laser by homogenizing and by phase shifter 24 phase modulated to form light distribution with negative peak, thus with laser radiation to substrate 26.Light pattern causes the crystallization of carrying out on the horizontal direction, and can make the size of big crystal grain in the semiconductor film increase for example about 10 μ m.Crystallization process is with high rapid change, and finishes in the utmost point short cycle of several 10 nanoseconds to hundreds of nanosecond.Setting has the reflection-type microexamination system of a few μ m, microscopically to observe, to monitor or to observe the image of the crystallization process that changes with hypervelocity.Reflection optical system is characterised in that: than the object lens of being made up of the lens with hole, and do not exist because aberration and the caused loss of absorption.

Reflection-type microexamination system comprises: reflection-type is observed lamp optical system 3, is used to launch the illumination light that is used to observe; And reflection-type microexamination optical system 4, it can receive the light beam of crystallization process regional reflex in the substrate 26 and with image it is presented on the screen in real time.Partial reflection type microexamination optical system 4 is shared with partial reflection type observation lamp optical system 3, and is set between imaging optical system 25 and the substrate fixed station 27.Common sparing makes the optical path of the optical path of illumination light and crystal laser overlapping coaxially, and constitutes complex optics.This complex optics is observed the optical system of process for can carry out crystallization process and crystalline state simultaneously under the situation that does not have the phase mutual interference.Annular is observed illumination light and microexamination light can use the high spatial resolution of a few μ m and the high instantaneous resolution of several nanoseconds to observe, monitor or measure crystallization process.

In reflection-type microexamination system, will be applied on the substrate 26 by half-reflecting mirror 33 and reflective annular optical element 3A from the observation illumination light that observation lighting source 31 sends.Observation light by substrate 26 reflections returns and enters the photoelectric detector 42 of microexamination optical system 4 by the optical path opposite substantially with illumination light.

Observe lamp optical system 3 and be furnished with the optical ring system that under the situation that does not stop crystallization laser optics path, passes through the fenestra of crystal laser for the center.The illumination light of observing lighting source 31 from high brightness becomes annular by the reflective annular optical element 3A of following explanation, and is applied to coaxially on the substrate 26 along the crystallization excimer laser.

The observation light of substrate 26 reflections returns by the optical path of the optical ring element 3A opposite with the illumination light optical path, and by half-reflecting mirror 33 and detected in microexamination optical system 4 subsequently.In microexamination optical system 4, the observation light that has transmitted by half-reflecting mirror 33 is imaged on the front surface of photoelectric detector 42 by imaging len 41, described front surface is a light receiving surface, and image by photoelectric detector 42 and image intensifier 43 acquisitions, converted to picture signal by two-dimensional imaging device 44, and extract as view data by image processing parts 45.

In observing lamp optical system 3, for example, beam expander 32 will form directional light from the illumination light that high brightness is observed lighting source 31, and this illumination light is guided to ring light element 3A by half-reflecting mirror 33.And then illumination light is owing to planar annular speculum 34 turns to substrate 26, and is focused on the semiconductor film on the substrate 26 by convex annular speculum 35 and annular recessed speculum 36.Annular observation illumination light illuminates the crystallization process zone in the crystallization process.The observation light of crystallization process regional reflex on the semiconductor film arrives half-reflecting mirror 33 via the recessed speculum 36 of annular, convex annular speculum 35 and planar annular speculum 34 by the optical path opposite with the illumination light optical path.Observe light and pass half-reflecting mirror 33 and imaging len 41, and on the optical receiving surface of photoelectric detector 42, form the image of semiconductor film intercrystalline process area.

For observing lighting source 31, high-intensity light source, for example xenon (Xe) photoflash lamp or visible laser source, as Ar laser, He-Ne (He-Ne) laser, can be used for allowing to observe with the instantaneous resolution of nanosecond, beam expander 32 preferably can utilize a small amount of lens to form directional light, with the loss of minimizing irradiates light, and can use for example non-spherical lens.Half-reflecting mirror 33 reflects from the illumination light of lighting source 31 and changes its direction, but transmission is by the semiconductor film reflection and from its observation light that returns.Optical path along the crystallization excimer laser is provided with planar annular speculum 34, convex annular speculum 35 and annular recessed speculum 36, thus they must be the annular and can not stop optical path.The fenestra of planar annular speculum 34 has the diameter of about 13mm in the position away from substrate 26 about 50mm, not stop excimer laser ground transmission excimer laser, suppose that the zone with this excimer laser of irradiation is approximately 2mm * 2mm to 5mm * 5mm on substrate 26, and the glancing angle of laser on substrate 26 is approximately 7 °.Reflection-type observation lamp optical system 3 can be considered and also can use other structure.

One of modification is as the method for observing illumination light with polarization laser.The use of polarised light can make illumination light fully with from substrate 26 reflections and be separated from its observation light that returns.Example of modification part of optical system has been shown among Fig. 2.As shown in the figure, at the front of beam expander 32 utilization polarizer 32A, and replace half-reflecting mirror 33 and use polarizing beam splitter 33A and quarter-wave plate 33B.Such structure allows polarization laser as light source.Quarter-wave plate 33B is set makes its crystallographic axis be offset 45 ° about the axis of homology of polarizer.Because this set, be configured to 90 ° by the resonance surface of the polarization of illumination laser of substrate 26 reflections and the resonance surface of observing polarization laser, make polarizing beam splitter allow illumination light to separate fully with illumination light

A kind of modification of optical ring element comprises planar annular speculum 34 is changed over the convex annular speculum.This structure allow convex annular speculum 36 be provided with the recessed speculum 35 of more approaching annular, or under the situation of not using annular recessed speculum 35 and convex annular speculum 36, allow illumination to be focused on the substrate 26.

In another kind of modification, convergent lens is set between half-reflecting mirror 33 and the planar annular speculum 34, and is arranged on outside the optical path of crystal laser.In this structure, can omit annular recessed speculum 35 and convex annular speculum 36, and planar annular speculum 34 can be provided with more near substrate 26, and can form its fenestra littler.

In another kind of modification, with longer distance annular recessed speculum 35 and convex annular speculum 36 are set, and planar annular speculum 34 is set betwixt.Other modification can be considered for the annular reflection optical system, as between phase shifter 24 and imaging optical system 25, planar annular speculum 34 being set, and a kind of in these modifications can be used.

Observation light by substrate 26 reflections arrives half-reflecting mirror 33, convex annular speculum 36, annular recessed speculum 35 and planar annular mirror 34 via the optical path opposite with the optical path of illumination light.Observing light passes half-reflecting mirror 33 and arrives microexamination optical system 4.

Except the optical ring element 3A and half-reflecting mirror 33 shared with observing lamp optical system 3, microexamination optical system 4 for example also comprises micro-imaging optical system 41, photoelectric detector 42, becomes image intensifier 43, image device 44 and imaging parts 45.

Pass the observation light of half-reflecting mirror 33 and handled by microexamination optical system 4, described microexamination optical system has for example at first by the described observation light of imaging len 41 imagings and subsequently with the function of enlarged image to its imaging.From the observation light in the crystallization process zone of a few μ m levels on the substrate 26 by imaging len 41 with the high-resolution imaging of a few μ m on the optical receiving surface 42a of photoelectric detector 42.The optical receiving surface 42a of photoelectric detector 42 is a slit shape, so that observe the crystalline state that changes with at a high speed.Optical receiving surface 42a is for being transformed into light the photolectric surface of electronics.Slit shape optical receiving surface 42a for example is the long rectangles of wide and several cm of several mm.The high spatial resolution that is formed on the crystallization process zone that has a few μ m resolution on the optical receiving surface 42a is strengthened by photoelectric detector 42 and image intensifier 43, and is adopted by image device 44 as high-definition picture.45 pairs of view data of image processing parts are carried out signal processing.Signal processing comprises, for example storage of the analysis of view data, view data and the view data demonstration on display unit 45c.

Photoelectric detector 42 is preferably for example photoelectric tube, as streak camera, as shown in Figure 3.For streak camera, can use the striped pipe, it can become the incident light image transitions photoelectron and convert thereof into light image subsequently once more, and the one dimension image is changed in time with the high instantaneous resolution of several nanoseconds.

Conventional striped pipe 42 is the vacuum tube of special purpose, and has the structure shown in Fig. 3.The formed image of incident light is focused on the slit shape optical receiving surface 42a and by its reception.Slit shape image is the one dimension image in the crystallization process zone.Optical receiving surface 42a becomes the photoelectron beam that produces among the photoelectron optical receiving surface 42a to pass scan electrode 42b-2 the incident light image transitions of one dimension.Scan electrode 42b-2 is furnished with a pair of electrode along X or Y scanning direction photoelectron beam.Apply scanning voltage SV from scanning circuit 42b-1 to scan electrode 42b-2.Scanning circuit 42b-1 according to such timing for scan electrode 42b-2 applies time dependent scanning voltage SV (referring to Fig. 3, Fig. 4 D), described timing is for passing through the timing from the described scanning circuit 42b-1 of triggering signal P2 (referring to Fig. 3, Fig. 4 B) control of timing controller (accompanying drawing 1,50).Photoelectron beam is according to the change of scanning voltage and being bent with the amount that changes, and the photoelectron beam image R of projection is presented at the time dependent diverse location place of fluorescent display screen 42c.The image projected R of institute is a high-definition picture, and wherein according to time sweep slit shape one dimension image, so that it becomes two dimensional image, and the instantaneous change of nanosecond is shown as the change that phosphor screen 42c goes up the position in the image that is received on the optical receiving surface 42a.Can whole be incorporated at least one among accelerating electrode 42d or the electronic multiplier 42e, to improve the sensitivity of striped pipe 42.

The high-resolution two-dimensional image that is formed on the phosphor screen 42c of striped pipe 42 is strengthened by image intensifier 43 brightness, forms high brightness two dimension high light image thus.That is to say that image intensifier 43 has following function.Picked up by the imaging len (not shown) by the high-resolution two-dimensional image that striped pipe 42 is obtained, and be imaged on once more subsequently on the photolectric surface of image intensifier 43.Photolectric surface is formed on the inwall of vacuum tank.The electron lens that the photoelectron that discharges from photolectric surface is set in the vacuum tank quickens, assembles and reduces, and drops on the phosphor screen in the image intensifier 43.The image that its brightness is strengthened by above-mentioned acceleration and minimizing effect is displayed on the phosphor screen of image intensifier 43.

Be presented at two-dimentional high light image on the phosphor screen of image intensifier 43 by image device 44, for example the two-dimensional CCD image device picks up, and is converted into view data.Because CCD image device 44 picks up and has the very image of a little light, preferably suppresses dark current and improves the S/N ratio.Therefore, the CCD image device of low temperature (for example, from bearing tens degrees centigrade approximately to the liquid nitrogen temperature) cooling of use down is preferred.

At imaging parts 45, for example under the control of the control circuit 45a of PC, to handling from the view data of CCD image device 44 and subsequently with its storage.Data processing comprises for example calculates scheduled time crystal region width later.View data and the data of being calculated are stored in memory unit 45b such as the memory, and are simultaneously displayed on as required on the display unit 45c.The people who is responsible for crystallization process can use the data that are presented on the display unit 45c to monitor the crystallization process.In addition, because view data is stored among the memory unit 45b, so under the control of control circuit 45a, extract required image and it is presented on the image-display units 45c as rest image or slow moving image.

Utilize this structure of microexamination optical system 4, can carry out necessary observation with the high spatial resolution of the high instantaneous resolution of several nanosecond and a few μ second.Laser crystallization apparatus 1 comprises timing controller 50.Timing controller 50 controls are used for as crystal laser source 10, observe various types of timings of lighting source 31 and microexamination optical system 4.Fig. 4 a to 4e shows these examples regularly.Synchronous with the radiation pulses of crystallization pulse laser EL (Fig. 4 A), timing controller 50 sends and begins to shine triggering signal P1 (Fig. 4 B) that observes illumination light OL and the triggering signal P2 (Fig. 4 B) that begins to apply for striped pipe 42 scanning voltage SV.When observation lighting source 31 received triggering signal P1, illumination light OL (Fig. 4 C) was observed in its emission.When the scanning voltage generator 42b of striped pipe 42 received triggering signal P2, scanning voltage generator 42b beacon scanning electric current 42b-1 produced for t _sThe scanning voltage SV that changes in time of time cycle, and scanning voltage SV is applied to scan electrode 42b-2 (Fig. 4 D).When scanning voltage applies when finishing, timing controller 50 be image device 44 transmission triggering signal P3 (Fig. 4 E), and image device 44 will become, and two dimensional image picks up as view data on the phosphor screen of image intensifier 43.

For example, Fig. 5 is the schematic diagram as the view data of above-mentioned acquisition, and the observed result of the semiconductor film that changes in the crystallization process has been described.Accompanying drawing shows the image that the time produced of the one dimension image that scans presumptive area in the semiconductor film in time, and described image changes in time.Trunnion axis is represented the position on the semiconductor film, and vertical axis is represented elapsed time.Be irradiated onto about 25 nanoseconds on the substrate 26 of crystallization by phase modulated and crystallization pulse laser with negative peak light distribution.Therefore, the zone that semiconductor film shone is melted, and fusion temperature has certain distribution, and is promptly according to the negative peak light distribution, low in the center, and in the high distribution in its both sides.When stopping crystal laser, the temperature of irradiation area begins to cool down.The temperature gradient of the corresponding negative peak light distribution of the temperature gradient in the cooling cycle, and begin to be cured or crystallization at the center of fusing.Crystallization position, promptly solid liquid interface moves to the outside according to time gradient from central cross.The semiconductor film that changes in the crystallization process carries out imaging by this way by the microexamination optical system, described mode is for being applied simultaneously on the crystallization process zone from observing the observation illumination light that lighting source 31 sends, and can realize with the image viewing of spatial resolution with a few μ m and the instantaneous resolution of several nanoseconds thus and/or measures crystalline state.Describedly be viewed as for example observation of crystalline state, and as crystal region size and the measurement of time in the crystallization process.

Under observation, although its actual be hundreds of μ m or large scale more, picture traverse can be configured to any required size.In Fig. 5, for simplicity's sake, the laser part with a peak pattern is shown, and width can be for example 10 μ m with enlarged image.The height of image can be configured to any required moment.At this, time range is configured to the application time corresponding to scanning voltage SV, t _s=300 nanoseconds.

When silicon thin film melted, it became metal, reflect visible light so well.On the other hand, crystalline portion is visible light transmissive well, especially ruddiness.Therefore, in viewed in reflected light, as bright image, and crystal region is observed as the case image with observed in the melting range.In Fig. 5, curing (crystallization) zone of silicon thin film is represented in the shadow region, and white portion is represented the melting range.The upper end of Fig. 5 is bright pattern (white portion) in whole width range corresponding to the instant moment after melting.Observe, the black part of crystallization at first appears at the center, and then the therefrom outside expansion of mind-set.That is to say that solid liquid interface moves to the outside from the center.In Fig. 5, show the one dimension image of time dependent presumptive area, process in time can be observed in Fig. 5 crystallization and advances downwards.The center in zone is adjusted to the negative peak part of laser beam, just the part that changed by phase shifter 24 of the phase place of KrF excimer laser.In this section and since the phase place of KrF excimer laser in its both sides by anti-phase, so the intensity of excimer laser is because interference therebetween and significantly reduce (desirable is zero).Therefore, the film temperature after the fusing is minimum, and begins the nucleus formation of silicon thin film the crystallization from this position.Therefore, according to the temperature gradient in the fusing, the crystal grain in Fig. 5 is grown downwards.The crystallite dimension of growth is approximately 6 μ m, and for example described crystal grain is the crystal grain of crystallization in the PMELA of present embodiment equipment.Therefore, can utilize the spatial resolution of a few μ m and the instantaneous resolution of several nanoseconds to observe crystallization process as image.

In Fig. 5, the example of the laser beam with a negative peak has been described., in actual crystallization process, regulate excimer laser to such an extent that comprise a plurality of negative peaks with light distribution by the phase transition mask.Illustrated among Fig. 6 A, 6B and Fig. 7 A, the 7B and used laser beam to carry out the observation example of crystallization process with a plurality of peak values.

Fig. 6 A, 6B show when using the black and white mask to form to have the irradiation excimer laser of the rectangle light distribution that contains peak value and trough, in several 10 μ m zones for the observed result of time cycle of hundreds of nanosecond from the crystallization process that is melted to crystallization.Fig. 6 A illustrates the light distribution of excimer laser, and wherein trunnion axis is represented the position and vertical axis is represented the relative intensity of laser, and Fig. 6 B represents the micro-image observed by means of streak camera.As above illustrated with reference to accompanying drawing, the image of being observed by streak camera is the image that produces by time sweep one dimension image on the presumptive area on the time dependent semiconductor film.At this, Fig. 6 B shows negative-appearing image, and expresses than described in Fig. 5 and anti-phase black and white image.That is, show melt portions, and show crystalline portion with white image with black image.The transverse width of accompanying drawing is 66 μ m, and vertical axis is corresponding to elapsed time, and the top of time is the starting point of time, and the time is process downwards, and whole height was equivalent to for 500 nanoseconds.Use has the black and white mask at line/interval of 5 μ m, and the excimer laser of wavelength that will have 248nm is with 0.42J/cm ²Intensity be radiated on the amorphous silicon membrane with 50nm thickness.It should be noted that used optical system is 1/5 scaled-down version, and N.A. is 0.125, as shown in Figure 6A, the peak intervals 10 μ m of excimer laser.In Fig. 6 B, as mentioned above, black region is the melting range, and white portion is a crystal region, and the zone of middle color is unfused amorphous silicon region.Because the irradiation of laser, amorphous silicon membrane fusing around the peak value part of light, and in the part corresponding to the trough of light, can not melt.Observe: crystallization starts from the both sides of melt portions and from then on passes in time, and crystallization was finished in postradiation 87 nanoseconds.

Fig. 7 A, 7B show another example that uses the phase shift mask to realize crystallization.Be similar to Fig. 6 A, 6B, Fig. 7 A shows the light distribution of excimer laser, and Fig. 7 B is the image that shows the crystallization process observed result.The intensity of removing excimer laser is 0.65J/cm ²In addition, illuminate condition and Fig. 6's is similar.Shown in Fig. 7 A, by using the phase shift mask, realize the remarkable change of excimer laser light distribution, and in the part of the recess of corresponding black and white mask, light intensity peak occurs.In addition, even in the light intensity trough, light intensity is low too, the light distribution that has relative small intensity difference on the whole therefore occurs.When the excimer laser irradiation with four peak values is to amorphous silicon membrane, melted the whole zone of shining, shown in Fig. 7 B.Described crystallization starts from 43 nanoseconds after the illumination.Crystallization is from the part of three paddy of corresponding light distribution, just as required from the minimum part of fusion temperature.Subsequently, crystallization is towards the peak value progress of light intensity, and perhaps solid liquid interface moves, and 125 nanoseconds behind excimer laser irradiation are finished crystallization.

From the above as can be known, the present invention can observe and come across after the rayed crystallization process from the hypervelocity of the nanosecond that is melted to crystallization of the silicon thin film of 125 nanosecond period only.In addition, can determine, also can control the crystallization of silicon thin film by the intensity distributions of regulating irradiates light.

Utilizing an example observing the crystallization process result to comprise focuses substrate 26 to the imaging plate of imaging optical system 25.Defocus, promptly the difference in height between the imaging plate of excimer laser and the substrate semiconductor-on-insulator film is caused by following several reasons.When the semiconductor film of imaging plate from substrate 26 of crystal laser (excimer laser) removed, fail to form the laser intensity in the anti-phase zone lower according to design.Therefore, the temperature of this part after fusing makes nucleus postpone than the temperature height at image space place, causes the delay that crystallization begins like this.In addition, it is not minimum part nucleation at laser intensity not only that nucleus tends to, and in other parts nucleation at random.Therefore, the chance that exists more crystal grain of growing to be in contact with one another, and the size of crystal grain-growth becomes littler.That is, the quality of crystal silicon film has descended.

The defocus reason of crystallizer in crystallization process for example comprises that substrate 26 is smooth inadequately, because fixedly large tracts of land substrate 26 caused bendings, and because the skew of the caused picture position of variations in temperature of imaging optical system 25.Imaging optical system 25 changes (increase) its temperature according to the high-energy excimer laser.Like this, for example, temperature change is 1 ℃ in imaging optical system 25, and image space for example changes 10 μ m.Consider the depth of focus of imaging optical system 25, for example be approximately ± depth of focus of 10 μ m that the side-play amount of image space is not negligible little just.

Can observe the skew of the image space of imaging optical system 25 in the following manner.T-T shown in Fig. 5 center shows at excimer laser irradiation and crossed scheduled time t behind the substrate 26 that carries out crystallization _MTime.Measure the width W (dash area) of above-mentioned moment crystal region by image processing parts 45.Image processing parts 45 use a kind of known pattern recognition techniques, according to the picture pattern calculating side-play amount of crystal silicon film.Institute's offset calculated is used for decision and whether is lower than predetermined acceptable defocus amount, and subsequently with its output.If image processing parts 45 decision institute offset calculated are unacceptable defocus amount, it is according to the position calculation correcting value of substrate 26.Platform driver 60 is on the basis of position correction amount, and the short transverse of the substrate 26 that calculates along above-mentioned image processing parts drives substrate fixed station 27, proofreaies and correct described position along the short transverse of substrate 26 thus.

As Another Application, description is utilized the method for laser crystallization apparatus 1 position substrate 26 of the present invention.Wherein form the method for crystallising of negative peak light distribution, can relatively easily determine to form the position of crystal grain by phase shifter 24.Photoelectric detector 42 and image intensifier 43 are temporarily removed from the optical path of imaging optical system 41.Subsequently, image device 44 is moved to the position of micro-imaging optical system 41, so that correct in such a way position substrate 26.For example, according to alignment mark substrate 26 is placed precalculated position on the X-Y-Z fixed station 27.After the reference alignment mark carries out the accurate adjustment in position, can begin crystallization process.On the screen of display unit 45c, show crystallization process, and just determine position at the semiconductor film of crystallization according to display.When detecting skew, if but skew exceeds receiving amount, and then image processing parts 45 can detect automatically according to alignment mark and be offset and proofread and correct.In addition, when shining crystal laser, can realize automatically being used for accurate adjustment by offset correction at every turn.Further, the anti-exposure process that will carry out after also being fed back to based on the result of the offset correction of alignment mark.

Below, illustrate that the present invention uses the reason of reflection-type microexamination system in the various microexamination system that uses in laser crystallization apparatus.Usually, microexamination system comprises that use is by the catoptrical system of substrate 26 reflections and the system of use transmitted light.Directly assemble in the microexamination system of observing light at microcobjective. microcobjective must place reflection-type and transmission-type substrate 26 near.The definite size that needs microcobjective.This causes a problem, even applying the method for reflection of observing illumination light for substrate 26 from the identical lopsidedness ground of irradiation crystal laser exactly, as hereinafter described, also be difficult under the situation that does not stop crystallization laser optics path, microcobjective is arranged in the space between laser crystallization optical system 25 and the substrate 26.In applying the method for observing light from behind obliquely, also there are some problems, as can becoming noise by the reverberation that reflects such as the rear surface of the substrate 26 of glass substrate, and by being difficult to by the performed focusing of glass substrate inclination transmission.

Reflection-type is observed lamp optical system 3 and is had the following advantages, and described optical system adopts has fenestra so that do not stop the reflective annular optical element 3A in crystallization laser optics path, and the coaxial observation light of utilization and crystal laser throws light on.For example, described advantage comprises owing to the absorption that lacks lens causes the small loss of observing light there is not aberration, and does not use microcobjective and can carry out imaging.Therefore, than observing the microexamination system that light tilts to enter and above-mentioned observation light is directly assembled by microcobjective, the reflection-type microexamination system of use reflection-type observation lamp optical system 3 is fit to as the microexamination system of laser crystallization apparatus 1.

Be similar to above-mentioned use reflection-type and observe the reflection-type microexamination system of lamp optical system 3, transmission microexamination system is fit to for the optics setting, this transmission microexamination system adopts similar annular optical element 3A, with from the coaxial observation illumination light of identical side-irradiation and crystal laser, and in described system, microcobjective is arranged on the rear surface., also there are some restrictions in this system, and for example substrate 26 exists its material by visible light transmissive to make, and must be set on the substrate fixed station 27 of stationary substrate 26 by the fenestra of observing light, and the aft section of platform 27 can not be used for other purpose.

Further, the semiconductor film on the processed substrate 26 (for example amorphous silicon membrane, polysilicon membrane) time is become metal in fusing, and the reflectance of visible light is very high.On the other hand, unfused silicon fiml and crystal silicon film be the transmits red visible light very well, makes the reflectance step-down.In this respect, the catoptrical method that is used to observe is applicable to how silicon thin film is melted with the high-contrast of crystallization and observes.

Microexamination optical system 4 described in the present embodiment not only has above-mentioned structure, and has the structure that is omitted part or other structure according to the following stated.

In a kind of modification, comprise accelerating electrode 42d or electronic multiplier 42e at striped pipe 42, and when being enough for the susceptibility of CCD image device 44 as the intensity of the master image of striped pipe 42 output, perhaps when the susceptibility of CCD image device 44 is very high, can omit image intensifier 43.

In another modification, use the gate CCD image device 44 that is commonly called as, it has the structure of omitting striped pipe 42 and integrated image booster 43 and CCD image device 44.Gate CCD image device only applies voltage at predetermined instant for the photoelectron multiplier, so that write down this two dimensional image this moment on phosphor screen, and then obtains two-dimensional image datas by CCD image device 44.Therefore, the situation of striped pipe 42 is used in contrast, can obtain alphabetic data in presumptive area., use the high instantaneous resolution of several nanosecond to be controlled to be the high voltage that photoelectron multiplier 42e applies,, in wide viewing area, obtain two dimensional image so that at predetermined instant.

The invention is not restricted to the foregoing description, and can make amendment.In addition, in use can omit a part of the present invention.

For example, can omit the mechanism of the substrate skew that is used for calibration of laser crystallizer 1,, provide and observe semiconductor film simply and melt variation with crystallization in time so that observed result is not being fed back under the situation of laser crystallization apparatus 1.

As mentioned above, according to the present invention, can be by image with the high instantaneous resolution Real Time Observation of the high spatial resolution of a few μ m and nanosecond and the fusing and the crystallization of measuring semiconductor film, or after crystallization, observe immediately and measure.In addition, for example feed back by crystallization according to the observation, laser crystallization apparatus and method for crystallising can be provided, wherein crystallization process is stable and realizes that effectively crystallization is to produce high-quality semiconductor film.

The invention is not restricted to the foregoing description, and under the situation that does not break away from spirit of the present invention, can the implementation phase in carry out various modifications.In addition, the foregoing description comprises the various stages, and obtains various types of inventions by disclosed a plurality of composition requirements are carried out appropriate combination.For example, can from some composition requirements shown in the embodiment, some composition requirements have been deleted.

Provided the foregoing description disclosed herein, can make any technical staff of this area can make and use the present invention.Those skilled in the art can realize the various modifications of these embodiment at an easy rate.

For those skilled in the art, expect other advantages and modification at an easy rate.Therefore, the present invention is not limited to aspect widely this illustrate and specific detail that illustrates and representative embodiment at it.Therefore, under the situation of the spirit and scope that do not break away from total inventive principle that claims and equivalent thereof limit, can carry out various modifications.

Claims (19)

1, a kind of laser crystallization apparatus comprises the crystal optics system, and this crystal optics system also melts laser radiation and this film of crystallization to the film that is arranged on the substrate, and described laser crystallization apparatus is characterised in that and comprises:

Lighting source is arranged on outside the optical path of described laser, and launches the illumination light that is used to observe, to illuminate described film;

Lamp optical system comprises the optical ring element, and described optical ring element has the described optical path of described laser in the center, and described illumination light is guided on the described film along described optical path from described lighting source; With

The microexamination optical system, it shows a width of cloth enlarged image, this image comprises the piece image one of at least of the fusing in the laser radiation zone in the described film or crystalline state.

2, laser crystallization apparatus according to claim 1, it is characterized in that: described optical ring element comprises the planar annular speculum, this planar annular speculum is arranged on the described optical path of described laser, and reflection and guiding arrive described film from the described illumination light of described lighting source.

3, laser crystallization apparatus according to claim 1, it is characterized in that: described optical ring element comprises annular recessed speculum and convex annular speculum, it is arranged on the described optical path of described laser, and reflection and guiding arrive described film from the described illumination light of described lighting source.

4, laser crystallization apparatus according to claim 1, it is characterized in that: described lamp optical system comprises one or more lens and the half-reflecting mirror that is arranged on outside the described optical path, and the guiding of described lens and half-reflecting mirror arrives described film from the described illumination light of described lighting source via described optical ring element.

5, laser crystallization apparatus according to claim 1, it is characterized in that: described optical ring element comprises planar annular speculum and annular recessed speculum and the convex annular speculum on the described optical path that is separately positioned on described laser, described planar annular mirror reflects and guiding arrive recessed speculum of described annular and convex annular speculum from the described illumination light of described lighting source, and the described illumination light that the recessed speculum of described annular and convex annular mirror reflects and guiding are reflected by described planar annular speculum arrives described film.

6, laser crystallization apparatus according to claim 5 is characterized in that: described microexamination optical system comprises:

The optical system that comprises described optical ring element, it amplifies and imaging is arranged on fusing or at least one image of crystalline state or at least one image of fusing that is changing or crystalline state in the laser radiation zone in the described film on the described substrate; With

Image device, it picks up the described image by the described film of described micro optical system expansion.

7, laser crystallization apparatus according to claim 5 is characterized in that: described microexamination optical system comprises:

The optical system that comprises described optical ring element, it amplifies on the photoelectron surface and imaging is arranged on fusing or at least one image of crystalline state or at least one image of fusing that is changing or crystalline state in the laser radiation zone in the described film on the described substrate;

Photoelectric detector, the electronics that its multiplication is produced by the lip-deep one dimension image of described photoelectron, and guide described electronics to first phosphor screen of this photoelectric detector, with two dimensional image by described one dimension image formation time scanning; With

Image intensifier is imaged onto described two dimensional image on its photoelectron surface, and quickens and reduce the electronics that is sent by the lip-deep image of described photoelectron, to form high brightness two dimension high light image on second phosphor screen of this image intensifier; And

Image device, it picks up described high brightness two dimension high light image on second phosphor screen of described image intensifier.

8, laser crystallization apparatus according to claim 1, it is characterized in that: described laser is excimer laser, and wherein said crystal optics system comprises phase modulation component, described phase modulation component becomes to have the light of predetermined light distribution with the excimer laser phase modulated of incident, has wherein passed the described film of described laser radiation of described phase modulation component.

9, laser crystallization apparatus according to claim 8 is characterized in that: described microexamination optical system comprises:

The optical system that comprises described optical ring element, it amplifies and imaging is arranged on fusing or at least one image of crystalline state or at least one image of fusing that is changing or crystalline state in the laser radiation zone in the described film on the described substrate; With

Image device, it picks up the described image by the described film of described optical system expansion.

10, laser crystallization apparatus according to claim 1 is characterized in that: described microexamination optical system comprises:

The optical system that comprises described optical ring element, it amplifies and imaging is arranged on fusing or at least one image of crystalline state or at least one image of fusing that is changing or crystalline state in the laser radiation zone in the described film on the described substrate; With

Image device, it picks up the described image by the described film of described optical system expansion.

11, laser crystallization apparatus according to claim 7 is characterized in that: described photoelectric detector is the striped pipe.

12, laser crystallization apparatus according to claim 10 is characterized in that: described image device is the cooling CCD image device.

13, laser crystallization apparatus according to claim 1 is characterized in that: described micro optical system is shared the described optical ring element of described lamp optical system.

14, laser crystallization apparatus according to claim 1 is characterized in that: also comprise:

The image processing parts are used to handle the described image by described microexamination optical system detection;

The platform driver, it has the function of regulating the position of described substrate according to the position data of the described substrate that is obtained by described image processing parts.

15, laser crystallization apparatus according to claim 1 is characterized in that: described film is amorphous silicon film or polysilicon film.

16, a kind of method of laser crystallization is characterized in that comprising:

Emission laser;

With described laser radiation to the film that is arranged on the substrate, so that described film melts and crystallization;

Optical path along described laser, utilize and observe the zone that illumination light illuminates laser radiation, wherein via reflection-type optical ring element, described illumination light is guided to described film, the optical path of described optical ring element and described laser is provided with and passes described laser coaxially, and the described optical path of wherein said laser is arranged on the center;

Amplify also imaging from the observation illumination light of the reflection of described film, as at least one image of fusing in the described film or crystalline state; And

Pick up described enlarged image.

17, laser crystal method according to claim 16 is characterized in that: during described film is arrived in described laser radiation or after described film is arrived in described laser radiation, realize the illumination of described observation illumination light to described film.

18, laser crystal method according to claim 16 is characterized in that: the step of picking up described image also comprises:

As view data, wherein said enlarged image is fusing or at least one image of crystalline state or at least one image of fusing that is changing or crystalline state in the described film with described enlarged image;

Handle the described view data of described film;

According to the result of image processing, calculate the position data of described substrate; And

According to described position data, regulate the position of described substrate.

19, laser crystal method according to claim 16 is characterized in that: described substrate is a glass substrate, and described film is formed in amorphous silicon film or polysilicon film on the described glass substrate.

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