KR20130102007A - Assist exposure apparatus - Google Patents

Abstract

The auxiliary exposure apparatus (AE) (10) is a device for aligning a substrate (G) in a predetermined posture A UV irradiation unit 32 for irradiating the resist on the substrate G with ultraviolet light (UV) of a predetermined wavelength; and a light emitting element in the UV irradiation unit 32 for emitting light A cooling mechanism 36 for cooling the light emitting element in the UV irradiation unit 32 to a set temperature and a light source for measuring the illuminance of ultraviolet irradiation by the UV irradiation unit 32. [ A measurement unit 38, and a control unit 40 and a memory 42 for controlling each unit in the apparatus.

Description

[0001] ASSIST EXPOSURE APPARATUS [0002]

The present invention relates to optical lithography, and more particularly to a co-exposure apparatus that irradiates ultraviolet light to a resist film applied on a substrate to be processed separately from a normal exposure process for transferring a mask pattern.

In a photolithography technique, a resist (photosensitive resin) is coated on a thin film (a film to be processed) deposited on a surface of a substrate to be processed, a photomask pattern (circuit pattern) is transferred to a resist on the substrate, It is a technique to write. The photolithography technology is a key technology that makes miniaturization and high density of an integrated circuit in a semiconductor device, an FPD (flat panel display), and the like.

Up to now, miniaturization of circuit patterns by optical lithography has been advanced in various ways. In recent years, trends in refinement are maintained by short-wavelength ultraviolet light used for exposure, the adoption of a phase shift mask and a chemically amplified resist. Specifically, the exposure wavelength of ultraviolet light is shifted from 248 nm (Krf) to 193 nm (Arf). Further, for example, in the halftone phase shift mask method, even in the light shielding portion of the photomask, a slight amount of light is transmitted to improve the resolution performance due to the interference between the amplitude of the light passing through the mask opening and the amplitude of the transmitted light around the mask opening . The chemically amplified resist can achieve high sensitivity by amplification reaction using an acid catalyst and achieve high developing contrast and high resolution.

Japanese Patent Laid-Open No. 2002-341525

However, as the miniaturization of the circuit pattern by the photolithography progresses as described above, the in-plane uniformity of the film thickness and line width of the resist pattern obtained on the substrate after the development process becomes large. That is, as the circuit pattern becomes finer, the film thickness of the resist pattern becomes thinner and the line width becomes thinner, and it becomes increasingly difficult to improve the in-plane uniformity of the resist pattern. Furthermore, in addition to the basic steps of resist coating, exposure, and development, optical lithography also involves a pre-treatment or post-treatment process, such as baking, between the basic processes, If the property is low, the rate of in-plane uniformity of the film thickness and line width of the resist pattern as a result of the final process is controlled. When a plurality of processes having low in-plane uniformity of process results are present, this problem becomes more complicated and more prominent.

With respect to this problem, many techniques have been conventionally proposed to individually improve the in-plane uniformity of each process result. On the other hand, the deviation (error) from the set value is measured by measuring the film thickness or the line width of the resist pattern as the final process result at several representative points on the substrate. For example, in the prebaking step preceding the exposure step A method of adjusting the heating temperature for each region in accordance with the deviation has been conventionally performed. Therefore, in the baking apparatus, area-divided type surface heaters are used, or pores capable of independently changing or adjusting the height of the proximity fins on the hot plate are formed. However, this conventional technique has a limitation in hardware, and the adjustment of the height of the proximity pin has a problem that the number of steps of the adjustment work is very large, and the achievement of uniformity in the surface is not good.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art described above and provides an auxiliary exposure apparatus capable of realizing a significant improvement in the thickness or line width of the resist pattern after development processing or the in-plane uniformity in optical lithography.

The auxiliary exposure apparatus of the present invention is characterized in that, in optical lithography, in addition to the exposure process for transferring the mask pattern onto the resist film coated on the substrate to be processed, the resist film on the surface of the substrate is irradiated with ultraviolet light of a predetermined wavelength An auxiliary exposure apparatus comprising: an ultraviolet light irradiation unit in which a plurality of irradiation areas provided with one or a plurality of light emitting elements for emitting the ultraviolet light are arranged in a first direction; A scanning mechanism for relatively moving the ultraviolet irradiating unit with respect to the substrate in a second direction intersecting with the first direction so as to expose a resist film on the surface of the substrate; Through the light emission driving section, the command value of the optical output for the irradiated area Illuminance characteristic acquiring section for acquiring a command value-illuminance characteristic indicating a illuminance relationship between an illuminated position on the substrate and a corresponding irradiated position on the substrate; An illuminance control section for controlling the light emission driving section based on the command value-illuminance characteristic for each of the irradiation areas so as to match or approximate a target value; and a control section for obtaining the command value-illumination characteristic And a temperature management mechanism for controlling the temperature of each of the irradiation areas to the same or approximate temperature when performing the above-mentioned exposure scanning.

In the above apparatus configuration, the resist on the substrate surface is irradiated with ultraviolet light having a light intensity independent from each of a plurality of irradiation areas arranged in a line in the second direction of the ultraviolet irradiation unit. The ultraviolet irradiating unit relatively moves on the substrate in the first direction by the scanning mechanism so that the entire resist on the substrate surface is subjected to ultraviolet irradiation scanning or exposure scanning.

During this exposure scanning, the illumination control unit controls the light emission driving unit on the basis of the command value-illumination characteristic for each irradiation area such that the illuminance of the irradiated position on the substrate opposite to each irradiation area coincides or approximates the target value . Here, the command value-illuminance characteristic is a characteristic (function) indicating the illuminance relationship between the command value of the light output for the irradiation area and the corresponding irradiated position on the substrate, and is acquired in advance by the illumination characteristic acquisition section.

The temperature management mechanism uses the command value-roughness characteristic when the roughness characteristic acquisition section obtains the command value-roughness characteristic for each irradiation area and when the roughness control section uses the command value-roughness characteristic during the subsequent exposure scanning. The temperature is controlled to be the same or approximate. By this, ultraviolet rays can be irradiated to the resist on the surface of the substrate at each position on the substrate at an exposure amount as set, and a desired secondary exposure treatment can be performed.

According to the auxiliary exposure apparatus of the present invention, it is possible to realize a significant improvement in the precision of the film thickness or the line width of the resist pattern after development processing or the in-plane uniformity in the photolithography.

1 is a block diagram showing a configuration on a process flow of an inline system for optical lithography to which the auxiliary exposure apparatus of the present invention can be applied;
2A is a diagram showing a format for partitioning a product area on a substrate in a matrix form in the embodiment;
FIG. 2B is a diagram showing a structure for calculating and mapping measured values of the film thickness (or line width) of the resist pattern for each unit area of the matrix section on the substrate. FIG.
2C is a diagram showing a structure for calculating and mapping a correction exposure dose for each unit area of a matrix section on a substrate.
2D is a diagram showing a structure for calculating and mapping a target value of roughness for each unit area of a matrix section on a substrate.
3 is a block diagram showing the configuration of the auxiliary exposure apparatus in the embodiment;
4 is a perspective view showing a configuration of a reflux conveying unit and a UV irradiation unit in the auxiliary exposure apparatus.
5 is a side view showing a configuration of a parallel transporting unit and a UV irradiation unit in the auxiliary exposure apparatus.
6 is a front view showing the entire configuration of the UV irradiation unit in the auxiliary exposure apparatus and the configuration of the main parts of the cooling mechanism.
7 is a bottom view showing the arrangement of the irradiation area and the light emitting element in the line shape irradiating unit of the UV irradiation unit.
8 is a block diagram showing an overall configuration of a cooling mechanism in the auxiliary exposure apparatus;
9 is a diagram showing a configuration of an irradiation area temperature control section in the cooling mechanism.
10 is a block diagram showing a configuration of a light emission driver and an illuminance measurement unit in the auxiliary exposure apparatus.
11 is a partially exploded front view showing a configuration of an illuminance meter moving mechanism in the auxiliary exposure apparatus.
12 is a graph showing an example (a linear function) of a command value-illuminance characteristic;
13 is a diagram showing a structure for storing attribute data of command value-illumination characteristics on a table in a memory;
14 is a diagram showing a structure for calculating and mapping command values for each unit area of a matrix partition on a substrate;
15 is a schematic plan view showing scanning between a substrate and a UV irradiation unit in the auxiliary exposure process of the embodiment;
16 is a schematic plan view showing the operation of auxiliary exposure processing in the embodiment;
17 is a sectional view showing one modification of the cooling mechanism.
Fig. 18 is a diagram showing the arrangement of irradiation areas and cooling plates in the modification of Fig. 17; Fig.
19 is a front view showing another modification of the cooling mechanism;
Fig. 20 is an enlarged front view showing a configuration in one group in the modification of Fig. 19; Fig.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

[Configuration of substrate processing system]

Fig. 1 shows a configuration on a process flow of a substrate processing apparatus to which the auxiliary exposure apparatus of the present invention is applicable in optical lithography. This substrate processing apparatus is, for example, an inline system for manufacturing an FPD and includes, as basic constitution, a resist coating unit CT, a mask exposure apparatus EXP and a developing unit DEP. The mask exposure apparatus EXP is a normal (regular) exposure apparatus for transferring a photomask pattern onto a resist on a target substrate G made of, for example, glass.

The substrate processing apparatus also includes a vacuum drying unit DP, a pre-baking unit PRB, and a cooling unit COL as standard equipment. The reduced-pressure drying unit (DP) exposes the substrate (G) immediately after the resist is applied to the resist coating unit (CT) for a predetermined time in a reduced-pressure atmosphere to evaporate the solvent contained in the resist to a predetermined level. The prebake unit PRB heats the substrate G to a predetermined temperature before the mask exposure processing to evaporate the residual solvent in the resist and improves the adhesion between the resist and the base film. The cooling unit COL cools the substrate G to a reference temperature immediately after the pre-baking process.

The auxiliary exposure apparatus (AE) 10 of the present invention is disposed, for example, between the reduced-pressure drying unit DP and the prebak unit PRB in the process flow. In this case, in the auxiliary exposure apparatus (AE) 10, for the purpose of improving the accuracy or the in-plane uniformity of the film thickness (or line width) of the resist pattern obtained after the development process, A special auxiliary exposure process is performed.

This substrate processing apparatus is provided with a resist pattern inspecting section 12, an input section 14, and an arithmetic processing section 16 in order to impart information or data necessary for auxiliary exposure processing to the auxiliary exposure apparatus (AE) The resist pattern inspecting section 12 is a resist pattern inspecting section that forms a film of the resist pattern obtained on the sample substrate G after the developing process is completed by the developing unit DEP (usually, after completion of the heating process by a post bake unit The thickness (or line width) is measured, for example, at several representative points (for example, several tens) on the substrate G. [

The calculation processing unit 16 is composed of a microcomputer including a memory and various interfaces and has functions of an interpolation unit 18, a correction exposure amount calculation unit 20 and an irradiation map (production) creation unit 22. The input unit 14 has a keyboard, a mouse, a touch panel, or the like, and has various conditions (for example, a keyboard, a mouse, or a touch panel) input to each unit in the system, , Initial value, and the like.

The interpolation section 18 performs interpolation processing on the film thickness (or line width) of the resist pattern on the basis of the measured value at the representative point of the substrate G obtained by the resist pattern inspecting section 12, (Precisely an estimated value) in another position or area on the image. 2A, the product area PA on the substrate G is partitioned into a matrix shape, and a measurement value of the film thickness (or line width) of the resist pattern for each unit area (i, j) of the matrix section (Or the estimated value obtained in the interpolation processing) A _ij is calculated and mapped as shown in Fig. 2B on a table constructed in the memory, for example. In the drawings, in order to facilitate understanding and illustration, the matrix partition is represented by 9 columns (j = 1 to 9). Actually, both the number of rows and the number of columns of the matrix divisions are at least several tens, and more than 100 in the large FPD substrate.

The correction exposure amount calculation unit 20 calculates the correction exposure amount B _ij for each unit area (i, j) of the matrix section on the substrate G, and maps the correction exposure amount B _ij on the table constructed in the memory as shown in FIG. 2C, for example. Here, the correction exposure dose B _ij is an exposure dose for bringing the difference (error) between the measured value and the set value closer to 0 with respect to the film thickness (or line width) of the resist pattern in each unit area (i, j).

When the resist used in this substrate processing apparatus is, for example, a positive type, the change in the film thickness and line width of the resist pattern becomes larger as the exposure amount increases at each position on the substrate G, and as the exposure amount becomes smaller, And the change in the line width becomes smaller. In this substrate processing apparatus, ordinary mask exposure processing by the mask exposure apparatus EXP and auxiliary exposure processing by the auxiliary exposure apparatus (AE) 10 are performed in multiple. Therefore, in the normal mask exposure processing in the mask exposure apparatus EXP, the auxiliary exposure processing by the auxiliary exposure apparatus (AE) 10 is expected, and the exposure amount is set to be smaller than that in the case where the auxiliary exposure processing is not performed desirable.

The irradiation map creating unit 22 calculates a target value C _ij of illuminance for each unit area (i, j) of the matrix partition on the substrate G and, for example, do. Here, when the ultraviolet irradiation time per unit area (i, j) of the matrix section in the auxiliary exposure apparatus (AE) 10 is t _S , C _ij = B _ij / t _S.

[Configuration and operation of auxiliary exposure apparatus]

3 shows the configuration of the auxiliary exposure apparatus (AE) 10 according to the embodiment of the present invention. This auxiliary exposure apparatus (AE) 10 has, as a hardware configuration, a flat conveying section 30 for conveying the substrate G in one horizontal direction (X direction) in a predetermined posture (for example, A UV irradiation unit 32 for irradiating a resist on the substrate G, which is carried by the flat conveying unit 30, with ultraviolet light (UV) of a predetermined wavelength, and a drive current for light emission for the light emitting element in the UV irradiation unit 32 A cooling mechanism 36 for cooling the light emitting element in the UV irradiating unit 32 to a set temperature and a light intensity measuring unit 34 for measuring the illuminance of ultraviolet irradiation by the UV irradiating unit 32 A control unit 40 for controlling each part in the apparatus (in particular, the flat conveying unit 30, the light emission driving unit 34, the cooling mechanism 36, and the illuminance measurement unit 38) And a memory 42 for storing or storing various programs and data used by the computer. The control unit 40 includes a microcomputer, and performs various necessary arithmetic processing and control described below according to a predetermined program.

The flat conveying section 30 includes a roller conveying path 46 in which a plurality of rollers 44 are laid out in the conveying direction (X direction), and a posture in which the substrate G is viewed on the roller conveying path 46 And a scan driver 50 for rotationally driving the rollers 44 via a transmission mechanism 48 having, for example, a belt, a gear, or the like. The roller conveying path 46 is connected to the conveying system of the front side vacuum drying unit DP and the conveying system of the rear side pre-baking unit PRB in the process flow (FIG. 1). The flat conveying section 30 conveys the substrate G which has undergone the reduced pressure drying processing by the reduced pressure drying unit DP into the auxiliary exposure apparatus AE 10 in a flat state, The substrate G is transported in a flat state for scanning with the auxiliary exposure process, and the substrate G after the auxiliary exposure process is transported to the prebake unit PRB in a pseudo order. Further, the control unit 40 is capable of detecting or grasping the current position of the substrate G through a position sensor (not shown) disposed on the roller transport path 46.

As shown in Figs. 4 and 5, the UV irradiating unit 32 is installed in the middle of the roller conveying path 46. Fig. The UV irradiating unit 32 is configured as a long unit extending straight in the horizontal direction (Y direction) orthogonal to the substrate transport direction (X direction). The UV irradiating unit 32 directs the line shape irradiating unit 54 downward And is disposed above the roller conveying path 46. It is also possible to provide a lifting mechanism for adjusting the height position of the UV irradiating unit 32, though the illustration is omitted.

6 shows the overall configuration of the UV irradiation unit 32 and the main configuration of the cooling mechanism 36. As shown in Fig. The UV irradiation unit 32 is provided with a plurality of surface mount type ultraviolet light emitting elements, for example, LED elements in a predetermined layout on a lower surface 52a of one support plate 52 extending straight in the unit longitudinal direction (Y direction) And has an irradiation section 54 having a line shape. The support plate 52 includes a metal having a high thermal conductivity, for example, aluminum.

As shown in Figure 7, UV irradiation unit 32, a line-shaped irradiation section 54 of the irradiation area of a plurality of (nine) in the longitudinal direction (Y direction) of the support plate _{(52) SE 1, SE 2} , SE ₃ , ... , And SE ₉ , respectively. (N = 9) corresponds to the number (9) of columns of the matrix partition set in the product area PA of the substrate G, and the nth irradiation area SE _n (n = 1 to 9) corresponds to the matrix partition N "

In each irradiation area SE _n , one or a plurality (six in the illustrated example) of LED elements J ₁ , J ₂ , ... , J ₆ one column or a plurality of columns are arranged in (two rows in the example shown). One set of LED elements J ₁ , J ₂ , ..., J ₁ , J ₂ , ... provided in each irradiation area SE _n , J ₆ is electrically are connected in series, and simultaneously emitted by the same or common drive current I _n from the light emission driving unit 34, each irradiation area SE _n directly below the As will be described later with respect to Figure 10 The ultraviolet rays of a predetermined wavelength are irradiated to the resist on the surface of the substrate G (the nth column of the matrix section and the periphery thereof)

As shown in Fig. 6, under the line shape irradiating section 54, elongated diffusing plates 56 for widening the irradiation angle of each irradiation area SE _n are arranged in parallel. The light of the LED element is strong in directivity, intensifying the downward light intact, and weakening the downward light. The diffusion plate 56 is used to correct this. The light having passed through the diffuser plate 56 has a uniform illuminance within a predetermined area. On the back surface side of the line shape irradiating section 54, that is, the upper surface of the support plate 52, a plurality (nine) of flat plate Peltier modules PM ₁ to PM ₉ are arranged in a row. Each of the Peltier modules PM _n is positioned behind (directly above) the corresponding irradiation area SE _n and the cooling surface (heat absorbing surface) thereof is placed on the support plate (Not shown). A heat sink 60 of a fin structure is coupled to the upper surface of the Peltier modules PM ₁ to PM ₉ , and a cooling fan 62 is provided above the Peltier modules PM ₁ to PM ₉ .

As shown in Figure 8, the cooling mechanism 36 is installed at each of the irradiation area SE _n, 1 pair of Peltier module PM _n, RTD (58 (n)) and the irradiation area temperature control unit (64 (n)) . 9, the irradiation area temperature control unit 64 (n) has a bridge circuit 66, a differential amplification circuit 68, a comparator 70, and a Peltier drive circuit 72. [

The bridge circuit 66 and the differential amplifying circuit 68 extract the resistance change of the temperature-measuring resistor 58 (n) according to the present temperature T as a voltage signal. The comparator 70 compares the voltage signal (temperature detection signal) MT from the differential amplification circuit 68 with the reference signal ST _n indicating the set temperature T _n from the control unit 40 and generates a comparison error ΔT _n . The Peltier driving circuit 72 supplies the driving current to the Peltier module PM _n by, for example, the PWM driving method so that the comparison error? T _{n is set} to zero. The Peltier module PM _n is formed by arranging the p-type semiconductor and the n-type semiconductor alternately electrically in series via the electrodes, and when the current flows, the surface of the Peltier module PM _n from the cooling surface (heat absorbing surface) ). Thereby, the irradiated area SE _n (particularly the LED elements J ₁ , J ₂ , ..., J ₆ ) thermally coupled to the cooling surface of the Peltier module PM _n via the support plate 52 is cooled.

The set temperature T _n is a reference value for maintaining the temperature of each irradiation area SE _n (in particular, the temperatures of the LED elements J ₁ , J ₂ , ..., J ₆ ) at a set value. Normally, the set temperatures T ₁ to T ₉ are selected as common (same) values for all the irradiation areas SE ₁ to SE ₉ , and a temperature example lower than the ambient temperature, that is, a little (preferably several degrees Celsius) Lt; RTI ID = 0.0 > 20 C < / RTI > Naturally, the set temperatures T ₁ to T ₉ may be different between the irradiation areas SE ₁ to SE ₉ .

As described later, in order to increase the throughput of the auxiliary exposure processing, if the scanning speed is increased, the exposure time is shortened, and the illuminance required to obtain the desired correction exposure dose at each position on the substrate G opposed to each irradiation area SE _n becomes high . As a result, the emission intensity to be set for each irradiation area SE _n and further the driving current I _n increase. However, if the driving current is large, the heat generation amount of the LED element is remarkably increased. Moreover, unless the heat dissipation is quickly and efficiently performed as a semiconductor element sensitive to heat, the light output (radiation illuminance) thereof tends to become unstable.

In this embodiment, as will be described later, all the irradiation areas SE ₁ to SE ₉ are driven to emit light independently by the light emission driving part 34, and the respective irradiation intensities are independently controlled. Cooling mechanism 36 by a configuration having a respective research area per SE _n 1 sets of the Peltier module PM _n, RTD (58 (n)) and the irradiation area temperature control unit (64 (n)) as described above, the radiation A passive cooling operation is performed for each irradiation area SE _n so as to enhance the cooling in the irradiation area having a high illuminance and weaken the cooling in the irradiation area in which the irradiation illuminance is low. Therefore, active (open loop) cooling control (forced cooling) in which a temperature sensor (a temperature-resisting resistor) is not mounted is not preferable here. This is because, even when all of the irradiation areas SE ₁ to SE ₉ are uniformly cooled as well as when they are cooled individually for each irradiation area SE _n , for example, if active cooling (forced cooling) of 15 ° C or less is performed, The low irradiation area is because the LED temperature becomes too low and the time delay occurs until the illumination is stabilized.

In this embodiment, even if the scanning speed is set high to increase the throughput of the auxiliary exposure processing, or even if the irradiance roughness greatly differs between the irradiation areas, from the end to the end of the line shape irradiating part 54, ₁ to SE ₉ can be stably and accurately maintained at the respective set temperatures T ₁ to T ₉ . This is very important in carrying out the exposure amount correction processing using the respective command value-illumination characteristics for each irradiation area SE _n as described later.

Fig. 10 shows the configuration of the light emission driver 34 and the illuminance measurement unit 38. As shown in Fig. The light emission driving section 34 includes an LED driver 74 (n) for each irradiation area SE _n . One set of LED elements J ₁ , J ₂ , ..., J ₁ , J ₂ , ... provided in each irradiation area SE _n , J ₆ is electrically constitutes a load circuit of the LED drivers (74 (n)) in a serial connection. The control unit 40 outputs the digital signal DV _n of the voltage value display as the command value V _n of the light emission output for each irradiation area SE _n . The digital signal DV _n is converted into an analog voltage signal AV _n by a digital-analog converter (DAC) 76 (n), and the analog voltage signal AV _n is given to the LED driver 74 (n). LED drivers (74 (n)), LED elements in the constant current source, and having a circuit, the art survey area the driving current I _n accordance with the command value (voltage signal) V _n from the control unit 40 to the constant current SE _n J _1, J ₂ , ... , And supplies it to J _6. Thus, the LED elements J ₁ , J ₂ , ... , J is _6, and the light-emission drive by the same or common drive current I _n, emits a predetermined wavelength of ultraviolet light.

Generally, LED devices are subject to individual differences and aging. Therefore, the driving current be supplied to the same, the individual LED elements J _1, J _2, ... _n in each irradiation area SE , J ₆ are different from each other, and the combined output thereof also changes with the elapse of time, and it is never uncommon that the irradiance illuminance or the irradiated intensity of each of the irradiated areas SE ₁ to SE ₉ varies with each other, to be.

In this embodiment, in consideration of the characteristics of such an LED element, the illuminance measuring unit 38 is provided and the light amount of the light emitted from the light emitting unit 34 is measured through the light emission driving unit 34 and the illuminance measurement unit 38 in the control unit 40 And the roughness characteristic acquisition operation is performed periodically.

The illuminance measuring unit 38 includes an illuminometer 80 for measuring the illuminance of ultraviolet rays and an illuminance meter moving mechanism 80 for moving the illuminometer 80 in the direction of the irradiation line (Y direction) (Not shown). The illuminometer 80 has a photoelectric conversion element, for example, a photodiode near the top portion 80a, and generates an electric signal (illuminance measurement signal) ML corresponding to the light intensity of the ultraviolet light incident on the light receiving surface . The roughness measurement signal ML output from the roughness meter 80 is sent to the control unit 40 via an analog-to-digital converter (ADC)

11, the illuminance meter moving mechanism 82 is provided with an illuminometer 80 so as to be at the same height as the surface of the substrate G when the light receiving section 80a of the illuminometer 80 moves on the roller conveying path 46 The carriage 86 and the illuminometer 80 are mounted on a rail 88 mounted on the carriage 86 and extending in parallel with the UV irradiating unit 32 in the Y direction by, for example, a linear motor So that the illuminometer 80 can be stopped or stopped at an arbitrary position on the rail 88. The external wiring (electric cable) of the light meter 80 is accommodated in the cable bear 90. The UV irradiation unit 32 and the rail 88 are provided in the middle of the adjacent rollers 44. When the roughness characteristic acquisition operation is not performed, the carriage 86 and the illuminometer 80 are placed on the roller conveying path 46) to the outside (side).

Here, the illuminance characteristic acquisition operation in this embodiment will be described. This illuminance characteristic acquisition operation is performed periodically, for example, at a constant device operation time or every predetermined day of the month. The controller 40 controls the light emission driving unit 34, the cooling mechanism 36, the illuminance measurement unit 38, and the light emission control unit 34 to stop the flat conveying unit 30 (with no substrate G on the roller conveying path 46) Lt; / RTI >

Under the control of the control unit 40, the cooling mechanism 36 operates in exactly the same manner as when auxiliary exposure processing is performed. That is, the cooling mechanism 36 maintains the temperatures of the irradiation areas SE ₁ to SE ₉ of the UV irradiation unit 32 at the set temperatures T ₁ to T ₉ , respectively, in accordance with the reference signals ST ₁ to ST ₉ from the control unit 40 A passive cooling operation is performed. As described above, the respective set temperatures T ₁ to T ₉ may be normally selected to the same value.

On the other hand, the light emission driving unit 34 and the illuminance measurement unit 38 operate in conjunction with each other under the control of the control unit 40 as follows. That is, the light emission driving section 34 first drives the first irradiation area SE ₁ to emit light with a drive current of a predetermined value. In accordance therewith, the illuminance measurement unit 38 moves the illuminometer 80 to a position directly under the first irradiation area SE ₁ . The illuminometer 80 outputs the illuminance measurement signal ML at each position. Control portion 40 while the fine moving the light meter 80 back and forth in line direction (Y direction), by monitoring the light intensity measurement signal ML from the light meter 80, first, the highest immediately illuminance in the vicinity of the bottom of the irradiated area SE ₁ The position (peak position) P ₁ is determined, and the position of the illuminometer 80 is adjusted to the peak position P ₁ .

Subsequently, the control unit 40 instructs the light emission driving unit 34 to output light emission command values V _{1 -1} , V _{1 -2} , ..., m (m is an integer of 2 or more) , V _{1 -m} , and outputs the light emission output command values V _{1 -1} , V _1-2 , ... , Illuminance measurement signals ML output from the illuminometer 80 in response to V _{1 -m} are introduced, and the illuminance measurement values L _{1 -1} , L _{1 -2} , ..., L _{1 at the} peak position P ₁ , And L _{1 -m} are obtained. Then, the light emission output command values V _{1 -1} , V _{1 -2} , ... , V _{1 -m} and the illuminance measurement values L _{1 -1} , L _{1 -2} , ... , And L _{1 -m} are plotted on the graph to obtain, for example, the command value-illumination characteristic? ₁ (in the case of n = 1) of the linear function as shown in FIG. This command value-roughness characteristic? ₁ is expressed by the expression? = A ₁ V + b ₁ , where a ₁ is the slope of the straight line of the primary function and b ₁ is the intercept.

Control portion 40 controls the second to ninth josa area SE ₂ to SE ₉ to also, the light emitting driving part 34 and the illumination through the measuring part 38, and repeats the operation of the the same, and each command value-illuminance characteristics alpha ₂ to alpha ₉ are acquired.

In this embodiment, in order to enhance the accuracy of the auxiliary exposure process, the irradiation area with respect to the n-th column, the area of SE _n and matrix compartment substrate G on the opposing, for (for example, approximating the art survey area SE _n to the next one The illuminance characteristics? _N-1 and? _{N + 1 of the} illuminated areas SE _{n -1} and SE _{n +1} , respectively. In this case, the illuminometer 80 receives the respective ultraviolet light from the adjacent irradiation areas SE _{n -1} and SE _{n +1} at the first peak position P ₁ immediately below the first irradiation area SE ₁ and measures the illuminance.

The control unit 40 performs predetermined attribute data (gradients) defining the main command value-illumination characteristic? _N and the adjacent command value-illumination characteristics? _N-1 and? _{N + 1} acquired for each irradiation area SE _n as described above , Intercept) are stored on a table, for example, as shown in Fig. Every time the illuminance characteristic acquisition operation is performed periodically, the table contents are updated by replacing with newly acquired command value-illumination characteristics? _N ,? _N-1 ,? _{N + 1} .

Subsequently, auxiliary exposure processing in this embodiment will be described. Under the control of the control section 40, not only the light emission drive section 34 and the cooling mechanism 36, but also the parallel transport section 30 operate. The flat conveying section 30 conveys the substrate G which has undergone the reduced pressure drying processing by the reduced pressure drying unit DP into the auxiliary exposure apparatus AE 10 in a flat state, The substrate G is transported in a parallel manner for scanning of the auxiliary exposure process. Here, the transport speed v is pyeongryu, the scanning speed in the auxiliary exposure process, each unit area of the matrix blocks of the substrate G (i, j) of time t _S come party ultraviolet irradiation is related. That is, if the proportional constant is K, v = K / t _S is inversely proportional.

The control unit 40 sets the latest command value-roughness characteristics? _N and? _N-1 (FIG. 2) held in the irradiation map (FIG. 2D) input from the arithmetic processing unit 16 and the table of the memory 42 prior to the auxiliary exposure processing , 14 with reference to γ _{n + 1} (Fig. 13), and calculates the command value V _ij for each substrate matrix for each unit area (i, j) of a block on the g, for example, a table on which is constructed in the memory 42 As shown in Fig.

Here, each command value V _ij is determined or selected so as to obtain the desired roughness C _ij by adding all of the main command value-roughness characteristic α _j and the adjacent command value-roughness characteristics β _j-1 , γ _{j + 1} . (I, 2) to (i, 9) in the i-th row of the matrix section, the desired illuminance C _{1 , 1} The respective command values V _{i , 1} to V _{i , 9} of the i-th row are determined or selected so as to obtain C _{1 ,} C ₉ . Thus, for example, by the command value V _{1, 1} to V _{1, 9} variables La and roughness C _{i, 1} to C _{i, 9} to its original value, the command value-illuminance characteristics (a linear function) α _n ,? _n-1 ,? _{n + 1} (n = 1, 2, ..., 9) are solved. Alternatively, a numerical value suitable for the variables (command values V _{1 , 1} to V _{1 , 9} ) of the command value-roughness characteristics? _N ,? _N-1 ,? _{N + 1} method to be filled repeatedly roughness C _{i, 1} to C _i, computing a _9, and roughness C _{i, 1} to C _i, until the calculated value of ₉ close to the respective desired value for the assigned predetermined count employing, as appropriate do.

On the other hand, the control unit 40 operates the cooling mechanism 36 in exactly the same manner as in the operation of obtaining the roughness characteristic. That is, the cooling mechanism 36 performs the passive cooling operation so that the temperatures of the irradiation areas SE ₁ to SE ₉ of the UV irradiation unit 32 are maintained at the set temperatures T ₁ to T ₉ , respectively.

15, the control unit 40 causes the substrate G and the UV irradiating unit 32 to perform scanning through the light emission driving unit 34 and the flat conveying unit 30 for the auxiliary exposure process. In this scanning, when the unit areas (i, 1) to (i, 9) of the ith row of the matrix section on the substrate G pass directly under the UV irradiation unit 32, gives a (74 1) to (74 9) of each command value V _i, V _i to _{1, 9} of the i-th rows on. Thereby, the unit area of the i-th row (i, 1) to (i, 9) in the relative UV irradiation line direction from the line-shaped irradiation section 54 of the unit (32) (Y direction) irradiation area independent light per SE _n from Shaped ultraviolet ray having an output is irradiated with the setting illuminance C _{i , 1} to C _{i , 9} for a certain period of time. Here, the constant time irradiation of the i-th row may be either continuous irradiation or pulse irradiation.

Thus, as shown in Fig. 16, when the substrate G passes directly under the UV irradiating unit 32, the illuminance of each unit region (i, j) on the irradiation line (each row of the matrix partition) Auxiliary exposure is performed. When the auxiliary exposure process is completed, the substrate G is sequentially sent to the pre-bake unit PRB, the cooling unit COL, the mask exposure apparatus EXP and the development unit DEP. As a result, on the substrate G taken out from the developing unit DEP, the film thickness (or line width) of the resist pattern showing the desired accuracy and in-plane uniformity is obtained.

[Other Embodiments or Modifications]

Cooling of the auxiliary exposure unit (AE) (10) according to the above described embodiments mechanism 36 are each irradiated area SE _n for each pair of the Peltier module in the UV irradiation unit (32) PM _n, one trillion people area temperature control unit (64 (n)) and the RTD (temperature sensor) (58 (n)) installed, and RTD (58 (n)) is detected the temperature T is the set temperature T _n, one trillion people area temperature control unit (64 to match to the ( n) is configured to supply the driving current I _n to the Peltier module PM _n by closed-loop control.

17, it is also possible to provide a configuration in which the drive current I _n is supplied to the Peltier module PM _n by the open loop control without using the RTD (temperature sensor) 58 (n) It is possible. In this case, each of the illumination area temperature control units 64 (n) may be constituted only by the Peltier drive circuit 72. [ However, the control unit 40 applies correction according to the command value V _n to the reference signal ST _n given to each of the illumination area temperature control unit 64 (n). That is, the command value V _n reference signal ST _n to the larger enhanced relatively cool to and the command value V _n weaken the relatively cool to the smaller to be applied to the LED driver (74 (n)) of the light emission driving unit 34 Calibration is performed.

In the case where the cooling mechanism 36 is constructed by the open loop control method, it is preferable to minimize the temperature interference between the adjacent irradiation areas SE _n and SE _{N +1} . Therefore, as shown in Figs. 17 and 18, for example, a configuration in which the support plates 52 (n) and 52 (n + 1) are placed on the irradiation areas SE _n and SE _{N +1} , respectively It can be suitably adopted. In this case, each of the support plates 52 (n) and 52 (n + 1) is mounted on a resin holder 92 having a low thermal conductivity, for example. The heat insulating portion for preventing temperature interference between irradiation areas adjacent to each other is also applicable to the closed loop control method.

As another modified example of the cooling mechanism 36, for example, as shown in Figs. 19 and 20, several successive irradiation areas SE _n , SE _{N +1} , SE _{N +2} a to the one group, each group pair of the Peltier module PM _M, may take a configuration in which the illumination area temperature control unit (64 (M)) and the RTD (temperature sensor) (58 (M)).

As described above, the number of rows of the matrix partitioned on the substrate G, that is, the number of the irradiation areas SE divided on the UV irradiation unit 32 is generally several tens or more or more than 100. Among them, the respective irradiance levels set in several successive irradiation areas SE _n , SE _{N +1} , SE _{N +2} are approximately approximate and not extremely different. Accordingly, in the cooling mechanism 36, a pair of Peltier module PM _M, by the illumination area temperature control unit (64), (M) and the RTD (temperature sensor) (58) (M), a continuous or close-up of each group The irradiation areas SE _n , SE _{N +1} and SE _{N + 2} can be stably and accurately co-cooled.

As for the cooling mechanism 36, various other modifications are possible. For example, the Peltier module is an optimal cooling means with excellent responsiveness. However, instead of the Peltier module, the responsiveness is reduced, but it is also possible to use, for example, a water cooling type cooling means.

As another modification, the cooling mechanism 36 may be a temperature management mechanism that controls the temperature of each irradiation area SE _n of the UV irradiation unit 32 to a set temperature higher than the ambient temperature (room temperature).

The UV irradiation unit 32 can also be modified in various ways. In particular, the layout in which the LED elements are arranged in each irradiation area SE _n is arbitrary, and for example, a configuration in which a plurality of LED elements are arranged in a staggered shape is also possible.

The auxiliary exposure apparatus (AE) 10 in the above-described embodiment has the flat conveying section 30 that conveys the substrate G in a flat state, and fixes the UV irradiation unit 32 at a predetermined position in the scanning direction . However, a scanning method in which the substrate G is fixed, for example, on a stage, a UV irradiation unit 32 is moved in the scanning direction on the stage, or a scanning method in which both the substrate G and the UV irradiation unit 32 are moved is also possible .

In the substrate processing apparatus (Fig. 1) in the above embodiment, the auxiliary exposure apparatus (AE) 10 is arranged between the reduced pressure drying unit DP and the prebak unit PRB in the process flow. However, the auxiliary exposure apparatus (AE) 10 can be disposed at any position in the process flow if it is between the resist coating unit CT and the developing unit DEP. The auxiliary exposure apparatus AE is provided between the pre-bake unit PRB and the cooling unit COL, between the cooling unit COL and the mask exposure apparatus EXP, or between the mask exposure apparatus EXP and the development unit DEP, It is also possible to arrange the light source 10.

Further, the auxiliary exposure apparatus (AE) of the present invention is applicable not only to a case where a positive type resist is used but also to an application using a negative type resist. The substrate to be processed in the present invention is not limited to the glass substrate for FPD, but may be a substrate for another flat panel display, a semiconductor wafer, an organic EL, various substrates for solar cells, a CD substrate, a photomask, and a printed substrate.

10: Auxiliary exposure device (AE)
12:
14:
16:
30:
32: UV irradiation unit
SE (1) to SE (9), SE (n): irradiation area
34:
36: cooling mechanism
38: illuminance measurement unit
40:
42: Memory
50:
52:
54:
56: diffuser plate
58 (1) to 58 (9), 58 (n): RTD (temperature sensor)
PM (1) to PM (9), PM (n): Peltier module
60: Heatsink
64 (1) to 64 (9), 64 (n): irradiated area temperature control section
74 (1) to 74 (9), 74 (n): LED driver
80: Roughness meter
82: Roughness meter movement mechanism

Claims (16)

An auxiliary exposure apparatus for irradiating ultraviolet light of a predetermined wavelength to a resist film on a surface of a substrate, in addition to an exposure process for transferring a mask pattern onto a resist film coated on a substrate to be processed in optical lithography,
An ultraviolet irradiation unit comprising a plurality of irradiation areas provided with one or a plurality of light emitting elements emitting the ultraviolet light in a first direction;
A light emitting driver for supplying a driving current for emitting light to the light emitting element for each of the irradiation areas;
A scanning mechanism for relatively moving the ultraviolet irradiating unit with respect to the substrate in a second direction intersecting the first direction so as to expose a resist film on the surface of the substrate;
For each of the irradiation areas, a command value-illuminance characteristic that indicates an illuminance relationship between a command value of light output for the irradiation area and a corresponding irradiated position on the substrate through the light emission driving unit Wow,
Controlling the light emission driving section based on the command value-illuminance characteristic for each of the irradiation areas such that the illuminance of the irradiated position on the substrate facing each irradiation area coincides or approximates the target value during the exposure scanning, An illuminance control unit,
Having a temperature management mechanism for controlling the temperature of each irradiation area to the same or approximate temperature at the time of acquiring the command value-illuminance characteristic and then performing the exposure scan for each of the irradiation areas, Secondary exposure apparatus. The method of claim 1,
The light emitting device is a surface-mount LED device,
The said ultraviolet irradiation unit is the auxiliary exposure apparatus provided with the said LED element in the support member with high thermal conductivity in each said irradiation area. The method of claim 2,
The said temperature management mechanism is a secondary exposure apparatus which has a cooling mechanism couple | bonded with the said support member. The method of claim 3,
The cooling mechanism,
A Peltier module attached to the support member toward the cooling surface;
A heat sink connected to the heat dissipation surface of the Peltier module,
And an illumination area temperature control unit for supplying a predetermined current to the Peltier module under constant current control. 5. The method of claim 4,
The auxiliary exposure apparatus, wherein the Peltier module and the illumination area temperature control unit are provided for each of the irradiation areas. The method of claim 5,
For each of the irradiation areas, an auxiliary temperature sensor is separately attached to the support member, and the illumination area temperature controller supplies a driving current to the Peltier module to match the temperature detected by the temperature sensor with a set temperature. Exposure apparatus. The method of claim 5,
For each said irradiation area, the said illumination area temperature control part supplies the drive current according to the said command value to the said Peltier module. 8. The method according to any one of claims 5 to 7,
And a heat insulating portion for preventing thermal mutual interference between two adjacent irradiation areas. 5. The method of claim 4,
All of the irradiation areas are divided into a plurality of groups along the arrangement direction, and the Peltier module and the illumination area temperature control part are provided for each group. 10. The method of claim 9,
Wherein a temperature sensor is separately attached to the support member for each group and the illumination area temperature control unit supplies a driving current to the Peltier module so that the temperature detected by the temperature sensor matches the set temperature, . 11. The method according to claim 9 or 10,
And a heat insulating portion for preventing thermal mutual interference between adjacent two groups. The method according to any one of claims 1 to 7, 9 and 10,
Wherein the illuminance characteristic acquiring section
Receiving the ultraviolet light emitted from each of the irradiation areas in accordance with a predetermined command value at the same height position as the surface of the substrate when the ultraviolet light is irradiated from each of the irradiation areas during the exposure scanning, A photoelectric conversion element for outputting a signal indicative of the intensity,
An illuminance measurement unit for obtaining a measured value of illuminance based on an output signal of the photoelectric conversion element,
And a function determination section for plotting a plurality of the command values and the illuminance measurement values respectively corresponding thereto to determine a function suitable for the command value-illuminance characteristics. The method according to any one of claims 1 to 7, 9 and 10,
Wherein the scanning mechanism has a substrate conveying portion of a reflux type in which the substrate is conveyed at a constant speed in the second direction in a posture for viewing the substrate. The method according to any one of claims 1 to 7, 9 and 10,
And a stage for fixing the substrate, wherein the scanning mechanism moves the ultraviolet irradiating unit in the scanning direction on the stage. The method according to any one of claims 1 to 7, 9 and 10,
Wherein the product area on the substrate is divided into a matrix and the row direction and the column direction of the matrix are respectively associated with the first and second directions, And the illumination target value is set for each unit area of the matrix. 16. The method of claim 15,
Wherein the illumination target value is set based on a measurement value of a film thickness or a line width of the resist pattern after development processing at each position on the substrate or an error between an estimated value and a set value due to interpolation.

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