TWI590491B - Method for producing nano-pattern, patterned stamp and optoelectronics device with nano-pattern - Google Patents

Description

Manufacturing method of nano patterning structure, patterned template and photoelectric element with nano patterning structure

The present invention relates to a patterned structure, and more particularly to a method of fabricating a patterned structure, a patterned template or substrate produced, and a photovoltaic element having a patterned structure.

Light-Emitting Diode (LED) is the most important issue in the application of various light sources. With the expansion of the application range, the demand for LED output light is greatly increased. More and more important. Most of the blue and green LED processes use sapphire substrates as their choice for epitaxial substrates. Through the patterned Sapphire Substrate (PSS) structure design, the Threading Dislocations (TDs) on the GaN epitaxial layer can be reduced during the epitaxial growth process to improve the internal GaN luminous efficiency and externality. Quantum efficiency. The patterned sapphire substrate also changes the direction and angle of light travel within the LEDs for the efficiency of LED excitation source extraction. Fig. 1 is a schematic view showing the direction of the light path of the patterned sapphire substrate. Wherein, the light-emitting layer (such as the multilayer quantum well MQW) 12 above the substrate 10 is sandwiched between the two epitaxial layers 11 and 13 of opposite electrical properties (such as P-type and N-type). The solid line in the figure represents the path of the light emitted by the luminescent layer 12 inside the LED of the unpatterned substrate 10, and the light that does not enter the critical angle of the LED Escape Cone 130 (e.g., 23.6°) is infinite within the LED. reflection. The dashed line in the figure represents the path of the light emitted by the luminescent layer 12 inside the LED of the patterned substrate (as indicated by a set of sidewalls 10a in the figure), and the patterned substrate can change the direction of the light to enter the LED escape cone. The ratio of light within the critical angle of 130 can be effectively increased, thereby increasing the luminous efficiency of the LED. Based on the aforementioned advantages, the importance of patterned sapphire substrates is also becoming increasingly apparent. In addition to the application of the aforementioned patterned substrate, the periodic structure is also often applied to the surface of an LED or solar cell component as a Surface Texture Anti-Reflection Coating (ARC) or a photonic crystal ( Photonic Crystal, PhC) and many other applications.

In recent years, nanotechnology has flourished. In 1965, Intel co-founder Gordon Moore proposed Moore's Law, predicting that the number of transistors on a wafer of the same size would be multiplied between one and a half years to two years. growing up. The semiconductor industry is also constantly following the predictions of Moore's Law, which will inevitably reduce the line width of components from the previous hundreds of micrometers to the current mainstream line width of less than 100 nanometers. On the optoelectronic component application, in addition to the scattering effect of the traditional micro-structure pattern, the nanostructure can also control the light travel by adjusting the pattern size to a dimension close to or smaller than the wavelength of the light. Many advantages such as collimation and polarization have been paid more and more attention. Therefore, many methods for making nanostructure patterns have been published.

Photolithography is the most common patterning method in the semiconductor industry. It is mainly placed between a component (or substrate) and an exposure source by a metal mask with a specific pattern. The exposure pattern block is defined by the reticle pattern. However, the size of the optical lithography process is limited by the imaging principle. In addition, the price of the optical lithography process equipment at the nanometer scale is not high, which makes the entry threshold higher in the field, and most manufacturers cannot invest in development. In addition to the optical lithography process, electron beam lithography (E-beam Lithography) and interference lithography (Interferometry Lithography) can be used to fabricate nanopattern structures.

Electron beam lithography uses an electron beam to expose a wafer or reticle. The first step is to design and trace the pattern or line, using a computer workstation or PC and using a drawing software (eg L-edit, OPUS or Auto CAD). Depicts a pattern or line and produces a file format for the GDS II. After the graphic file is created, it is input into the control computer of the electron beam exposure system. The graphic file is further converted into a data format that can be read by the application provided by the electron beam exposure system itself, and the electron beam can be controlled via the computer. The wafer, substrate or reticle on which the photoresist layer is formed is defined in accordance with the originally designed pattern and by the positioning movement of the susceptor in the xy direction. The defined pattern or line is then transferred to the wafer, substrate or mask used using an ICP dry etching apparatus. In order to successfully transfer the pattern defined by the electron beam to the substrate used, the selection of the substrate is generally made of materials such as germanium, glass or quartz. The biggest disadvantage of using the electron beam lithography technology to make the patterned base mold is that the process is very time consuming and is several times longer than the laser engraving lithography technology. If it is such a long time, problems such as focus error ( Focus error), you must re-exposure. Therefore, it is a time consuming method with low yield and high cost. The principle of interference lithography is to use the left and right symmetrical beam lines to interfere with each other to produce periodic light and dark stripes, which are irradiated on the photoresist on the surface of the substrate to define a pattern; this method can prepare large-area, periodic patterns, but It is not easy to prepare a non-periodic pattern. Since the laser light is Gaussian, the resulting interference fringes also have a Gaussian distribution, so the biggest disadvantage of using the interference lithography technique to make the patterned mold is that the pattern unevenness is easy to occur.

Based on the above-mentioned multiple considerations of making nano-patterns by lithography, the semiconductor industry continues to develop new nano-patterning techniques, and nano-Imprint Lithography (NIL) is one of them. The process of potential. Using nano transfer technology to make a patterned sapphire substrate, unlike the way in which reticle exposure is generally used to define graphics, this technique uses transfer to define the desired pattern, and the desired pattern depends on the graphics. For the surface of the mold for transfer. 2A-2G is a flow chart showing the production of a patterned substrate using a nano transfer technique. A resin layer or a photoresist layer (Fig. 2B) 21 is formed on the selected substrate (Fig. 2A) 20, and a mold core 23 having a special pattern is imprinted on the resin layer/photoresist layer (Fig. 2C). Then, demolding (Fig. 2D) and removing the resin or photoresist (Fig. 2E) outside the pattern to define the desired resin/resist pattern, and then dry or wet etching according to the pattern resin layer/photoresist layer 22. The etched substrate 20' (FIG. 2F) is formed, and finally the pattern resin layer/photoresist layer (2G) 22 is removed, and the pattern on the mold 23 is transferred onto the substrate 20 to complete the patterned substrate. 20'.

At present, the transfer technology can be mainly divided into Nano-Imprint Lithography (NIL), UV-Nanoprint (UV-NIL), and flexible nano transfer. (Soft Lithography) and Laser-Assisted Direct Imprint (LADI).

The hot-pressing form of nano-transfer technology mainly uses electron beam lithography, X-ray lithography or conventional optical lithography to etch the negative or negative nano or micro pattern on the enamel substrate. The mold of nano transfer is imprinted on a thermoplastic polymer material (such as PMMA, photoresist, etc.) under high temperature and high pressure, when the temperature of the thermoplastic polymer material exceeds its glass transition temperature Tg (glass) At the time of the transform temperature, the material deforms with the external force, and a pattern opposite to the convexity of the mold is obtained. Finally, the nano-transfer is completed by dry etching to remove the residual polymer at the bottom. Ultraviolet hardening nanotransfer (UV-NIL) is mainly made of quartz glass with high transparency and high strength as a mold. Pressure is applied at room temperature, so that the photoresist coated on the substrate can be pressed into the mold. In the kernel, the UV light source is used for irradiation, and the photoresist is solidified by the polymerization reaction after being irradiated by the ultraviolet light. After the film is removed, the photoresist remaining at the bottom is removed by dry etching to obtain the desired transfer. Graphics. The flexible nano transfer technology utilizes a flexible polymer material such as PDMS as a mold and is coated with a Self-Assembly Monomer (SAM) to imitate the ink seal. The method is to contact the mold with SAM and the substrate coated with the metal film. Since the SAM and the metal film are prone to strong bonding, a nano pattern can be defined on the substrate. Laser-assisted direct transfer technology (LADI) can use a transparent quartz substrate as a mold to contact a mold with a nano-pattern and a germanium substrate. When laser light is transmitted through the quartz to the germanium substrate, the energy of the laser light is instantaneously made. When the substrate is melted, an additional pressure is applied to the mold to transfer the pattern on the mold to the substrate. The time required for this method is very short, about several hundred nanometers. It can be done in seconds.

These nano-transfer technologies are characterized by the fact that their mold cores can be repeatedly imprinted on the entire surface of the wafer and the substrate, so it is very suitable for mass production processes. Moreover, the uniformity of the nanostructure pattern produced by the same mold transfer is better, which contributes to the improvement of the yield and the reliability. Therefore, how to make a mold core with a nano-pattern structure is one of the main key technical projects for making a patterned sapphire substrate.

The present invention relates to a method of fabricating a nanopatterned structure, a patterned template or substrate produced, and a photovoltaic element having a nanopatterned structure. The use of a photovoltaic element with a patterned structure can effectively improve its light extraction efficiency.

According to the present invention, a method for fabricating a nano patterning structure is provided, comprising: providing a substrate having a photosensitive coating thereon; placing the substrate on a machine table and rotating the substrate; providing a mine The source is such that one of the laser sources is irradiated intermittently on the photosensitive coating on the rotating substrate, and the laser light is displaced outward from the center of the corresponding substrate along a radius of the substrate for intermittent exposure (eg, a specific period of exposure) to form an exposed region on the photosensitive coating; and developing to remove the photosensitive coating of the exposed region to form a photosensitive pattern, wherein the photosensitive pattern comprises a plurality of dot structures gradually from the center of the substrate Arranged in a spiral shape.

According to the present invention, there is provided a patterned template comprising: a plurality of holes formed on a template, and the holes are arranged in a spiral arrangement from a center of the proximity template.

According to the present invention, a photovoltaic element having a patterned structure includes a substrate, a first epitaxial layer over the substrate, a second epitaxial layer on the first epitaxial layer, and a second epitaxial layer. Having a first conductivity; an active epitaxial layer over the second epitaxial layer; a third epitaxial layer over the active epitaxial layer, and a third epitaxial layer having a second conductivity. Wherein, the substrate or the third epitaxial layer has a patterned structure, and the patterned structure comprises a plurality of nano patterns.

In order to make the above-mentioned contents of the present invention more comprehensible, the following specific embodiments, together with the drawings, are described in detail below:

The embodiment proposes a manufacturing method of the patterned structure, which can be used to obtain a patterned template as a mold for re-imprinting during nano transfer; or directly define a patterned structure on the substrate of the element. The photoelectric element of the patterned structure of the application embodiment can effectively improve the light extraction efficiency.

<Method of Manufacturing Patterned Structure, and Patterned Template or Substrate Produced>

Fig. 3 is a schematic view showing the construction of a patterned structure by a stenciling machine according to an embodiment. Laser source 31 (Laser Beam Recorder, LBR) laser source 31, such as (Ar/Kr laser), through the Electro-Optical Modulator (EOM) 32 to control the laser power, sound and light modulator (Acoustic- The Optical Modulator (AOM) 34 outputs a predetermined pattern signal and, in conjunction with the autofocus system 35, performs a laser exposure of a predetermined pattern on the substrate 40 on the spin base 36.

Figure 4A is a partial schematic view of the laser exposure of the substrate on the rotating pedestal in Figure 3. Figure 4B is a schematic view of a substrate having a patterned structure of the embodiment. As shown in Fig. 4A, for the exposure mode of the engraving machine, the rotation of the susceptor 36 (such as a circular pedestal, such as the R direction) and the displacement characteristics of the laser beam are used to make the exposure. The laser beam can be distributed for a specific time (depending on the signal of the predetermined pattern), and is gradually moved from the center of the susceptor 36 to the outside (such as the M direction) to perform intermittent exposure, that is, corresponding to the near substrate 40. The center of the circle 0 is displaced outward in one of its radial directions for specific (or unspecified) periods and intervals of exposure. In this manner, a plurality of dot structures 41 as shown in FIG. 4B can be quickly defined, and the dot structures 41 are arranged in a spiral shape gradually from the center 0 of the substrate 40.

The arrangement of the dot structures 41 can be changed by adjusting the parameters of the engraving machine. As shown in FIG. 5A, it is a schematic diagram of different working cycles and patterning of the laser switch. The pattern period D represents the distance between two points of the nano pattern inscribed by the laser beam, which can be controlled by the duty cycle of the laser switch (Duty Cycle). The Pattern Width d1 represents the width of the nanopattern and is determined by the size of the laser spot of the bundled laser. The pattern length d2 represents the length of the inscribed nano pattern, which is determined by the duty cycle of the laser switch (Duty Cycle).

By changing the parameters in the laser engraving, a periodic or random pattern distribution can be written on the target carrier, which is suitable for mass production and high-variability nano-pattern writing process. Taking the pattern of the same pattern width d1_1 as an example, the longer the laser opening time is, the longer the pattern length d2 is. For example, the pattern length d2_1 of the nano dot pattern 511 is smaller than the pattern length d2_2 of the nano dot pattern 512. The pattern length d2_2 of the nano dot pattern 512 is smaller than the pattern length d2_3 of the nano dot pattern 513 (d2_1<d2_2<d2_3), and the nano dot patterns 511, 512, and 513 are respectively circular, elliptical, and Long oval. The pattern period D between the dot patterns may be the same or different, for example, the laser off time D_2 between the nano dot patterns 512 and 513 is longer than the laser off time D_1 between the nano dot patterns 512 and 511. . According to the manufacturing method of the embodiment, the size range can be adjusted from sub-micron to nano-sized.

In addition, by changing the r and θ values of the LBR engraving machine, the periodic variation and pattern change between the nano dot patterns can be controlled to achieve multi-cycle multi-angle pattern writing; wherein r is a nano dot pattern and The distance from the center 0 of the substrate 40, θ is the angle formed by the nano dot pattern of the nano dot pattern and the outer adjacent track.

As shown in Fig. 5B, a partial schematic view of the pattern is formed. The nano dot pattern 515 and the nano dot patterns 524 and 525 on the outer adjacent tracks are at an angle of θ2, and the nano dot patterns 525 and the nano dot patterns 534 and 535 on the outer adjacent tracks are θ1. The angle between the angle θ1 and the angle θ2 may be equal or unequal, depending on the actual application. The track pitch P represents a helical pitch, and the gauge is fixed when the radial velocity M of the outward movement of the laser beam is constant.

Figure 6 is a schematic diagram of a spirally arranged patterning structure of the embodiment, wherein D represents a pattern period (Pattern Pitch). The trajectory of this spiral pattern can be expressed by the polar coordinate equation: ρ=ρ0+υtθ/2π. Where ρ0 is the distance between the first point and the center 0 of the laser. υ is the speed at which the laser beam moves radially and outward. t is the time for the two lasers to write a point laser off. The LBR engraving machine is used to perform a laser exposure nano pattern, and the pattern parameters may also include a design of a gauge period, a pattern width, a pattern length, and the like as described above.

In addition, since the laser exposure engraving technique uses the rotation of the rotating base 36 to match the displacement of the laser beam for exposure and engraving, since the rotating base 36 has its maximum rotational speed limit, there may be a small central area that cannot be exposed without a pattern. . Therefore, in practical application, a larger size substrate exposure stencil can be selected, and the manufacturing process of the mold core is completed by the above-mentioned process as shown in FIG. 3-4B to form a large patterned structure (as shown in FIG. 6). The area mold core 70 cuts a small area of the mold core 72 of the desired size for the patterned portion for the subsequent transfer process. Figure 7 is a schematic view showing a large area of the mold core cut out of a smaller area of the mold. Although the figure 7 is illustrated by taking four small-area mold cores 72 as an example, it is not limited thereto, and other pieces may be cut to obtain a larger or smaller area than the mold core 72. Mold, which can be determined according to the conditions of actual application.

After the mold core is manufactured according to the method of the above embodiment, it can be applied to various existing transfer technologies, such as hot press forming nano transfer printing technology (NIL), ultraviolet light hardening nano transfer (UV-NIL), Various technologies such as Flexible Lithography and Laser Assisted Direct Transfer (LADI).

<Non-structured patterning of different structures, sizes and cycles>

The use of laser exposure technology to define the pattern, and with dry etching, electroforming and injection molding technology can successfully produce a variety of depths, widths and periodic or non-periodic pores, columns and grating structures . The dot pattern described above has a structure size that can be bound to the micron and submicron levels, and even to line widths below 100 nm. As shown in the embodiment of FIG. 5A and FIG. 6 , after selectively adjusting the gauge period P of the hole, the width d1 of the pattern, the length d2 of the pattern, and the period D of the pattern, periodicity of different patterns can be produced. The mold of the nano dot pattern.

In one embodiment, the gauge period P of the hole, the width d1 of the pattern, the length d2 of the pattern, and the period D of the pattern are each fixed, and when the width d1 of the pattern is equal to the length d2 of the pattern, the hole is distributed in the hexagonal closest packed structure, such as Figure 8A shows. In another embodiment, the gauge period P of the hole and the pattern period D are each fixed. When the pattern width d1 is different from the pattern length d2, it is as shown in FIG. 8B. In still another embodiment, when the gauge period P of the hole, the width d1 of the pattern, the length d2 of the pattern, and the pattern period D are each a variable, an irregular pattern as shown in FIG. 8C can be produced. Regarding the adjustment of the parameters such as the gauge period P of the hole, the width d1 of the pattern, the length d2 of the pattern, and the period D of the pattern, the user can set it himself to obtain the mold of the desired nano pattern, so the present invention does not Limited.

In the foregoing embodiments, the distance between two consecutive holes is, for example, 100 nm to 4000 nm, and the diameter, or the width and length of each hole are, for example, 50 nm to 3000 nm, and the height of the hole is, for example, 200 nm to 4000 nm. The material of the patterned mold core (template/substrate) is, for example, tantalum, tantalum carbide, gallium arsenide, aluminum oxide, indium phosphide, gallium nitride, tantalum, niobium, nickel, aluminum or plastic. However, the invention is not limited to the scope and materials set forth in the embodiments.

This technology can produce different imprinting molds according to the different techniques in the back-end process. The following is an example of a mold making method using three different materials.

<How to make molds of different materials> (A) Single crystal germanium wafer, glass and quartz substrate mold

Using laser technology to produce sub-micron or nano-scale patterns, the laser source used must be highly precise in positioning and focusing. The substrate used has a low reflectivity or even a transparent material, which does not cause interference from the reflected laser light from the substrate during the exposure process. Therefore, a transparent substrate material (such as glass, quartz).

The use of a single crystal germanium wafer as a substrate for laser exposure technology also has the advantage of easy dry etching. Although tantalum wafers have a reflectance of 40-50% for visible light waves, they are still within the tolerance of laser exposure technology, so tantalum substrates are often used in the production of high aspect ratio patterns.

9A-9E is a flow chart of a method for manufacturing a enamel material transfer mold. First, a positive or negative photoresist material is deposited on the selected substrate. The choice of the photoresist material depends mainly on the pattern to be fabricated, and is indistinguishable from the laser exposure technology; the same photoresist material can be used. It is an organic or inorganic photoresist. As shown in FIG. 9A, a photoresist 82 is applied to a substrate 81 (for example, a germanium substrate such as a single crystal germanium wafer, glass or quartz), and an organic positive photoresist is taken as an example. The substrate 81 which has been coated with the photoresist 82 is soft baked to remove excess solvent, and the photoresist 82 is laser exposed by a laser source 83 as shown in FIG. 9B to define a pattern to be formed, including The exposed area 82a and the non-exposed area 82b. The exposed substrate 81 is subsequently subjected to a developing process, as shown in Fig. 9C, the photoresist of the exposed region 82a which is reacted with the laser is removed using a suitable developer, and the photoresist of the non-exposed region 82b is left on the substrate 81. pattern. Thereafter, as shown in FIG. 9D, the substrate 81 is dry etched using the pattern as an etch mask; wherein the difference in the reaction rate of the etching gas in the dry etching with respect to the material of the photoresist 82 and the substrate 81 is directed to the uncovered photoresist The substrate 81 of the region is etched. After the etching is completed, the residual photoresist (i.e., the photoresist of the non-exposed area 82b) is removed to obtain a mold 81' for transfer, as shown in Fig. 9E.

(B) metal substrate mold

The metal transfer mold can be produced by electroforming. 10A-10F is a flow chart of a method for manufacturing a metal material transfer mold in the embodiment. A photoresist 92 of a suitable thickness and a suitable material is applied to the selected metal substrate 91, similar to the above-described process for transferring the mold core, as shown in FIG. 10A. The photoresist 92 is laser exposed by a laser source 93 as shown in Fig. 10B, including an exposed region 92a and a non-exposed region 92b to define the pattern to be fabricated. The exposed substrate 91 is then subjected to a developing process, and as shown in FIG. 10C, the photoresist of the exposed region 92a is removed to leave a photoresist pattern of the non-exposed region 92b on the substrate 91. Thereafter, a metal layer 95 is deposited on the surface of the substrate 91 by chemical plating, for example, having a thickness of, for example, 0.3 mm to 1 mm, and a metal material such as nickel or aluminum, as shown in Fig. 10D. Further, after peeling off the metal layer 95 and the substrate 91, a metal mold transfer 95' having a reverse pattern can be obtained as shown in Fig. 10E. If the mold is to be obtained in the same pattern as the photoresist pattern of the non-exposed area 92b, a metal layer can be further electroplated on the metal mold 95' as shown in FIG. 10E and peeled off. Another metal mold core 96 is shown in Fig. 10F. The metal mold cores 96 and 95' are complementary patterns.

(C) Plastic substrate mold

The method of making a plastic material transfer mold is similar to that of a metal mold core, and can be referred to the figure 10A-10F. A photoresist is also applied to the selected metal substrate, a photoresist pattern is defined after the laser exposure and development process, and a metal layer is plated on the surface of the substrate. After the metal layer and the substrate are peeled off, the obtained metal mold having the opposite pattern is placed in an injection molding machine to perform injection of the plastic mold. The plastic mold core obtained by injection molding has the same pattern as the photoresist pattern but is opposite to the metal mold core used for injection molding.

<Nano patterning mold making and its application to LED components> Embodiment 1: Applying a patterned substrate to an LED element

In the first embodiment, a nano-transfer enamel mold is formed as described above, and then the enamel mold is imprinted and etched as a stamp to obtain a nano-sized patterned substrate. Comparing the LED elements having the conventional flat substrate and the patterned substrate of the embodiment, it was found that the patterned substrate of the embodiment did improve the light-emitting efficiency of the LED element.

1. Production of nano transfer printing mold

Please refer to FIG. 11A-11F for a flow chart of a method for fabricating a nano-transfer enamel according to the first embodiment. As shown in Fig. 11A, a 6-inch wafer was used as the substrate 101, and a 100 nm-thick inorganic positive-type photoresist 102 was sputtered thereon as shown in Fig. 11B. Next, as shown in FIG. 11C, the substrate 101 is placed on a rotating base such as the aforementioned engraving machine (LBR), and the laser source 103 of the engraving machine exposes the photoresist 102, including the exposure area 102a and The non-exposed regions 102b define a pattern (such as a plurality of dot structures 41 as shown in FIG. 4B). Among them, the engraved line speed CLV 4.0 m / s, power 3.0 mW. After the laser exposure is completed, the area (exposure area 102a) which reacts with the laser is removed using an alkali solution. As shown in Fig. 11D, the developing solution used is potassium hydroxide (KOH) at a concentration of 0.05 M, and the development time is 45 sec. After the development was completed, the remaining developer was removed by immersing in deionized water for 10 minutes. The developed 6-inch wafer substrate is placed in a reactive ion etching apparatus for etching the tantalum substrate 101. As shown in FIG. 11E, the etching gas is argon (Ar, 9 sccm), hexafluoride. Sulfur (SF ₆ , 25 sccm), etching power 100 W, etching vacuum value 5 mTorr, etching time 1 minute 50 seconds. After the etching is completed, the residual photoresist on the substrate 101 (the photoresist of the non-exposed region 102b) is removed using an acid solution to form a patterned substrate 101' as shown in FIG. 11F; wherein the photoresist-dissolving solution configuration is, for example It was HCl (37%): H2O = 2:1 (volume ratio), soaking time was 10 minutes, and after completion, it was immersed in deionized water for about 15 minutes to remove residual hydrochloric acid.

2. Experiment and analysis of 矽模仁

The following is a comparison of the optical characteristics of two sets of different patterns and the optical characteristics of the LED components used in the experiment.

Scanning electron microscope (SEM) was used to observe the surface of the enamel containing inorganic photoresist before the dry etching (corresponding to the 11th chart), and it was found that the formed holes were flat and neat in shape (see Fig. 1). 12A and 12B are the results of surface analysis using an atomic force microscope (AFM) after the exposure and development, before the dry etching, the inorganic mold containing the inorganic photoresist. Among them, the pattern of the die model represented by Fig. 12A is: gauge period P = pattern period D = 800 nm, pattern width d1 = pattern length d2 = 350 nm; Figure 12B represents the model of the die model: rail The interval period P = pattern period D = 600 nm, the pattern width d1 = pattern length d2 = 250 nm. 2A and 2B are images taken by scanning electron microscopy (SEM) for the enamel mold containing inorganic photoresist before the dry etching after exposure and development, wherein the pattern of the enamel mold represented by FIG. 2A is: The gauge period P = pattern period D = 800 nm, pattern width d1 = pattern length d2 = 400 nm; Figure 2B represents the pattern of the 矽 model: rail period P = pattern period D = 600 nm, pattern width d1 = pattern length d2 = 300 nm.

3. Nano-patterned substrate obtained by stamping and etching

13A-13F are schematic flow diagrams of using a stencil embossing etch to make a patterned substrate. A resist film (Fig. 13B) such as a photoresist 132 is formed on the selected substrate (Fig. 13A) 131, and the substrate 131 is, for example, a sapphire substrate. The patterned substrate (the mold core 101) having the special pattern prepared as described above is imprinted on the photoresist 132 (Fig. 13C), and then the photoresist outside the pattern is demolded and removed to define the desired The photoresist pattern 132' (Fig. 13D) is further dry or wet etched according to the photoresist pattern 132' (Fig. 13E), and finally the photoresist pattern 132' is removed, and the patterned substrate 131' can be completed ( Figure 13F). 3A and 3B are AFM measurement diagrams and actual drawings of a nano-patterned sapphire substrate imprinted by the above-described method, wherein FIGS. 3A and 3B are patterned by a period of 800 nm and 600, respectively. The mold of nm is embossed.

Table 1 shows the height values of the imprinted substrate patterns for the mold cores of the pattern period of 800 nm and 600 nm and different duty cycles (Duty Cycle).

Of course, in addition to the embossing etching of the enamel mold to form the patterned substrate as shown in FIGS. 13A-13F, it is also possible to directly apply the LBR to the substrate as shown in FIGS. 14A-14F (eg, with etching). A photosensitive coating layer having a barrier property or a composite layer formed by etching the barrier layer and the photosensitive coating layer is formed with a nano-pattern structure, and a pattern structure is defined on the substrate by etching. A coating such as a photoresist 142 is formed on the substrate 141 (for example, a sapphire substrate). And as shown in FIG. 14C, the substrate 141 is directly disposed on the rotating base of the engraving machine (LBR), and the laser source of the engraving machine exposes the photoresist 142 (including the exposed area 142a and the non-exposed area 142b). ). After exposure development, a coating pattern corresponding to the non-exposed regions 142b is formed on the substrate 141 as shown in Fig. 14D. The substrate 141 is etched by using the photoresist pattern as a mask, as shown in FIG. 14E. After the etching is completed, the photoresist pattern is removed to form a patterned substrate 141' as shown in Fig. 14F.

Taking the patterned substrate 141' shown in Fig. 14F as an example, the duty cycle (Duty Cycle) can be defined as a/b. In one embodiment, when the duty cycle is 0.6-0.8, the height is 150 nm-200 nm, and the distance between adjacent two points of the same gauge is 550 nm-650 nm. In one embodiment, when the duty cycle is 0.4-0.6, the height is 200 nm-350 nm, and the distance between adjacent two points of the same gauge is 750 nm-850 nm. Of course, the invention is not limited thereto.

Further, although the patterns shown as the patterned substrates 131' and 141' are trapezoidal bumps, they are not limited thereto, and may be other patterns such as a conical pattern or a hemispherical pattern.

4. Fabricating LED components with patterned substrates

Whether it is to use a nano-transfer technology to create a patterned substrate, or to define a pattern directly on the substrate in LBR mode, it can be used as a patterned substrate for an applied photovoltaic element (such as an LED). Please refer to FIG. 15A-15C, which is a schematic diagram showing the manufacturing process of the LED component with the patterned substrate. First, as shown in Fig. 15A, a patterned substrate 151' having a patterned structure on the first surface 151a is provided.

In one embodiment, the patterned structure may include a plurality of nano patterns arranged in a spiral shape near the center 0 of the substrate. And the nano patterns may be periodically or non-periodically distributed. In one embodiment, the nanopatterns have a circular cross section or an elliptical cross section. The distance between two consecutive nanometer patterns is, for example, about 100 nm to 4000 nm, and the diameter, or width and length of each nano pattern is, for example, about 50 nm to 3000 nm, and the height of the nano pattern is, for example, about 200 nm. 4000 nm.

Then, as shown in FIG. 15B, a first epitaxial layer 153 is formed on the patterned substrate 151' and covers the patterned structure, and a second epitaxial layer 154 is formed on the first epitaxial layer 153, and The second epitaxial layer 154 has a first conductivity; an active epitaxial layer 155 is formed on the second epitaxial layer 154; and a third epitaxial layer 156 is formed on the active epitaxial layer 155, and a third The epitaxial layer 156 has a second conductivity. Thereafter, as shown in FIG. 15C, a first electrode 157 and a second electrode 158 are respectively connected to the second epitaxial layer 154 and the third epitaxial layer 156.

Photoelectric elements that can be used are, for example, light-emitting diodes, solar cells, photodetectors, or photodiodes. Taking the light-emitting diode as an example, the active epitaxial layer 155 in FIG. 15C is, for example, a light-emitting layer, and the second epitaxial layer 154 and the third epitaxial layer 156 are respectively one of different conductivity N-type material layers and A P-type material layer. In the embodiment, the distance T between the light-emitting layer (active epitaxial layer 155) and the patterned substrate 151' is, for example, 3 μm or more.

5. Light-emitting efficiency of LED components using patterned substrates

Fig. 16 is a graph showing the growth of the LED element in the patterned substrate (nPSS) of the embodiment, the pattern period is 600 nm, and the current and the output power of the conventional flat substrate (CSS). Table 2 series shows the percentage of the increase in the output power of the patterned component substrate (nPSS) of the embodiment when the current is 20 mA, 100 mA, and 200 mA, compared with the conventional flat substrate. For the pattern specifications represented by the curves npss (600 nm-1) and npss (600 nm-2), see Table 1.

From the curve trend of Fig. 16 and the related data of Table 2, it is clear that the nano-patterned substrate produced in the examples can be used to increase the luminous efficiency of the LED.

Fig. 17 is a graph showing the growth of the LED element in the patterned substrate (nPSS) of the embodiment, the pattern period is 800 nm, and the current and the output power of the conventional flat substrate (CSS). Table 3 series shows the percentage of the output power of the LED element having the patterned substrate (nPSS) of the embodiment as compared with the conventional flat substrate when the current is 20 mA, 100 mA, and 200 mA. For the pattern specifications represented by the curves npss (800 nm-1), npss (800 nm-2), npss (800 nm-3), and npss (800 nm-4), see Table 1.

From the curve trend of Fig. 17 and the related data of Table 3, it is clear that the nano-patterned substrate produced in the examples can be used to increase the luminous efficiency of the LED.

Fig. 18 is a graph comparing the current and the output power of the LED substrate grown in the patterned substrate npss (800 nm-1), npss (600 nm-1), and the conventional flat substrate (CSS). In Table 4, when the currents are 20 mA, 100 mA, and 200 mA in Figure 18, the LED components have patterned substrates npss (800 nm-1), npss (600 nm-1) compared to conventional flat substrates, and their output power is compared. The percentage increase.

From the trend of the curve in Figure 18 and the relevant data in Table 4, it can be clearly seen that the nano-patterned substrate produced in the examples, whether npss (800 nm-1) or npss (600 nm-1), It can be used to increase the luminous efficiency of LEDs. Among them, when the current is 200 mA, the light-emitting efficiencies of the patterned substrates npss (800 nm-1) and npss (600 nm-1) are as high as about 35% and 42%, respectively.

6. Apply patterned substrate to flip-chip LED component

The above embodiments are applicable to LED elements and solar cell elements having an anti-reflection layer. 19A and 19B show two flip-chip type LED elements with patterned substrates, respectively. The arrows in the figure represent the direction of light. The LED component and the solar component bonded to the 矽 substrate structure by a Flip-Chip packaging process, and the nano-scale structure fabricated on the original substrate surface of the component can provide a structured pattern surface and can improve the LED The light extraction efficiency of the component, or the light incident ratio of the solar component.

As shown in Fig. 19A, similar to Fig. 15C, the patterned structure in the LED element corresponds to the first surface 151a of the substrate to form the patterned substrate 151'. Therefore, the first epitaxial layer 153 is formed on the first surface 151a of the substrate and covers the patterned structure. The LED elements are bonded to a package structure 161.

As shown in FIG. 19B, the substrate has a first surface 152a and an opposite second surface 152b. The first epitaxial layer 153 is also formed on the first surface 152a, and the patterned structure on the patterned substrate 152' is located. On the second surface 152b.

Embodiment 2: Making a rough surface on the surface of the LED element by the above patterning method

In the first embodiment, the application level patterned substrate is used in the LED component, and in the second embodiment, the surface of the LED component is imprinted and etched by the surface of the LED component as described above, or The structural roughness is written directly on the surface of the LED component. The second embodiment can also improve the light extraction efficiency of the LED element.

Please refer to FIG. 20A-20G for a schematic diagram of a process for fabricating a rough surfaced LED component using a nano transfer technique. First, as shown in FIG. 20A, an LED structure is provided, including a substrate 191, a first epitaxial layer 193, a second epitaxial layer 194 having a first conductivity, an active epitaxial layer 195, and a device. The third conductivity layer is a third epitaxial layer 196. Next, as shown in FIG. 20B, a resist film such as photoresist 197 is formed on the third epitaxial layer 196, and the mold core 131' having a special pattern as described above is imprinted as shown in FIG. 20C. On photoresist 197; the photoresist outside the pattern is then demolded and removed to define the desired photoresist pattern 197', as shown in Figure 20D. The third epitaxial layer 196 is then embossed and etched according to the photoresist pattern 197' (Fig. 20E), and the photoresist pattern 197' is removed to form a patterned third epitaxial layer 196', as shown in Fig. 20F. Shown. Then, as shown in FIG. 20G, a first electrode 198 and a second electrode 199 are respectively connected to the second epitaxial layer 194 and the patterned third epitaxial layer 196' to complete the fabrication of the LED element.

21A-21G, which is a schematic flow diagram of directly writing a rough surface of a structure on a surface of an LED component using a stenciling machine (LBR). Similarly, an LED structure as shown in Fig. 21A is provided (Fig. 21A). A photoresist 197 is formed on the third epitaxial layer 196 (FIG. 21B), and the LED structure is directly disposed on the rotating base of the engraving machine (LBR), so that the laser source of the engraving machine is applied to the photoresist 197. After exposure, the photoresist pattern 197' is defined after development (Fig. 21C). The photoresist pattern 197' can then be thinned to achieve the desired height of the photoresist pattern 197" (Fig. 21D). The third epitaxial layer 196 is then etched according to the photoresist pattern 197" (Fig. 21E), And removing the photoresist pattern 197" to form a patterned third epitaxial layer 196' (FIG. 21F). Thereafter, as shown in FIG. 21G, a first electrode 198 and a second electrode 199 are respectively disposed. The two epitaxial layers 194 are connected to the patterned third epitaxial layer 196' to complete the fabrication of the LED elements.

In conclusion, the present invention has been disclosed in the above embodiments, but it is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

10, 20, 81, 131, 141, 191. . . Substrate

10a. . . Side wall

12. . . Luminous layer

11,13. . . Epitaxial layer

130. . . Escape angle cone

20’. . . Patterned substrate

21, 82, 92, 102, 132, 142, 197. . . Photoresist

82a, 92a, 102a, 142a. . . Exposure area

82b, 92b, 102b, 142b. . . Non-exposed area

twenty two. . . Pattern photoresist

twenty three. . . Mold

31, 83, 93, 103. . . Laser source

32. . . Electro-optic modulator

34. . . Acousto-optic modulator

35. . . Autofocus system

36. . . Rotating base

40, 101. . . Substrate

41. . . Dot structure

511, 512, 513, 515, 524, 525, 534, 535. . . Nano dot pattern

70. . . Large area

72. . . Small area

81’. . .矽模仁

91. . . Metal substrate

95. . . Metal layer

95’, 96. . . Metal mold

101’. . . Patterned substrate

132', 197', 197"... photoresist pattern

131', 141', 151'. . . Patterned substrate

151a, 152a. . . First surface

152b. . . Second surface

153, 193. . . First epitaxial layer

154, 194. . . Second epitaxial layer

155, 195. . . Active epitaxial layer

156, 196. . . Third epitaxial layer

196’. . . Patterned third epitaxial layer

157, 198. . . First electrode

158, 199. . . Second electrode

161. . . Package structure

O. . . Center of the substrate

P. . . Gauge period

r. . . LBR engraving machine radius of rotation

θ. . . Offset angle of LBR stereotype machine

D. . . Pattern cycle

D_2, D_1. . . Laser off time

D1, d1_1. . . Pattern width

D2, d2_1, d2_2, d2_3. . . Pattern length

T. . . Distance between active epitaxial layer and patterned substrate

Fig. 1 is a schematic view showing the direction of the light path of the patterned sapphire substrate.

2A-2G is a flow chart showing the production of a patterned substrate using a nano transfer technique.

Fig. 3 is a schematic view showing the construction of a patterned structure by a stenciling machine according to an embodiment.

Figure 4A is a partial schematic view of the laser exposure of the substrate on the rotating pedestal in Figure 3.

Figure 4B is a schematic view of a substrate having a patterned structure of the embodiment.

Figure 5A is a schematic diagram of different duty cycles and patterning of the laser switch.

Figure 5B is a partial schematic view of the formation of a pattern.

Fig. 6 is a schematic view showing a spirally arranged patterning structure of the embodiment.

Figure 7 is a schematic view showing a large area of the mold core cut out of a smaller area of the mold.

Figure 8A illustrates an application embodiment to produce a periodic nano dot pattern.

Figure 8B illustrates an application embodiment to create another periodic nano dot pattern.

Figure 8C illustrates an application embodiment to produce a nano dot pattern that is non-periodic.

9A-9E is a flow chart of a method for manufacturing a enamel material transfer mold.

10A-10F is a flow chart of a method for manufacturing a metal material transfer mold in the embodiment.

11A-11F are a flow chart showing a method for fabricating a nano-transfer enamel according to the first embodiment.

Fig. 12A and Fig. 12B show the results of surface analysis using an atomic force microscope after the exposure and development, before the dry etching, the inorganic mold containing the inorganic photoresist.

13A-13F are schematic flow diagrams of using a stencil embossing etch to make a patterned substrate.

Figures 14A-14F are schematic diagrams showing the flow of a nanoscale pattern structure on a coating of a substrate using a direct engraving machine (LBR).

15A-15C are schematic diagrams showing the manufacturing process of the LED component with the patterned substrate.

Fig. 16 is a graph showing the growth of the LED element in the patterned substrate (nPSS) of the embodiment, the pattern period is 600 nm, and the current and the output power of the conventional flat substrate (CSS).

Fig. 17 is a graph showing the growth of the LED element in the patterned substrate (nPSS) of the embodiment, the pattern period is 800 nm, and the current and the output power of the conventional flat substrate (CSS).

Fig. 18 is a graph comparing the current and the output power of the LED substrate grown in the patterned substrate npss (800 nm-1), npss (600 nm-1), and the conventional flat substrate (CSS).

19A and 19B show two flip-chip type LED elements with patterned substrates, respectively.

20A-20G are schematic diagrams showing the process of fabricating a rough surfaced LED component using a nano transfer technique.

21A-21G is a flow chart showing the rough surface of the surface of the LED element directly written by the engraving machine (LBR).

P. . . Gauge period

D. . . Pattern cycle

D1. . . Pattern width

D2. . . Pattern length

Claims (31)

A method for fabricating a nano patterning structure, comprising: providing a substrate having a photosensitive coating thereon; placing the substrate on a machine and rotating the substrate; providing a laser source One of the laser sources is irradiated with the photosensitive coating on the rotating substrate, and the laser light is exposed from the center of the corresponding substrate along a radius of the substrate to be exposed at intervals. Forming an exposed area on the photosensitive coating; and developing and removing the photosensitive coating of the exposed area to form a photosensitive pattern, wherein the photosensitive pattern comprises a plurality of dot structures, gradually emerging from a center of the substrate Spiral distribution. The manufacturing method of claim 1, further comprising: etching the substrate with the photosensitive pattern as a mask; and removing the remaining photosensitive coating to transfer the photosensitive pattern to the substrate. The manufacturing method of claim 1, wherein the substrate has an etch barrier layer and a photosensitive coating layer on the etch barrier layer, the method further comprising: transferring the photosensitive pattern to the etch by etching a barrier layer; removing the unetched photosensitive coating; transferring the pattern of the etch barrier layer to the substrate by etching; removing the etch stop layer that is not etched. The manufacturing method of claim 1, further comprising: plating a metal layer on the photosensitive pattern; and stripping the metal layer from the substrate to obtain a patterned metal opposite to the photosensitive pattern template. The manufacturing method of claim 4, further comprising: re-plating a second metal layer on the stripped pattern of the metal layer; and stripping the second metal layer from the metal layer to obtain One of the same patterns of the photosensitive pattern is a second patterned metal template. The manufacturing method of claim 4, further comprising: forming a plastic layer on the stripped metal layer pattern; and peeling the plastic layer from the metal layer to obtain the same pattern as the photosensitive pattern A patterned plastic mold. The manufacturing method according to claim 6, wherein the plastic layer is formed on the pattern of the metal layer by injection molding. The manufacturing method of claim 1, wherein the laser light is irradiated to the photosensitive coating on the rotating substrate at a specific time interval, and the laser light is from a center edge of the corresponding substrate The radius of the substrate is displaced outwardly for intermittent exposure with a particular period. The manufacturing method according to claim 1, wherein the continuous two-point structure formed has a distance dimension of about 100 nm to 4000 nm. The manufacturing method according to claim 1, wherein each of the dot structures formed has a diameter, or a width and a length dimension of about 50 nm to 3000 nm. The manufacturing method of claim 1, wherein the The material of the substrate includes tantalum, tantalum carbide, gallium arsenide, aluminum oxide, indium phosphide, gallium nitride, tantalum, niobium, nickel, aluminum or plastic. A patterned template includes: a plurality of holes formed on a template, and the holes are arranged in a spiral shape from a center of the template, wherein each of the adjacent holes is away from a center of the template The difference in pitch is a certain value. The patterned template of claim 12, wherein the holes are periodically distributed. The patterned template of claim 12, wherein the holes have a circular cross section or an elliptical cross section. The patterned template of claim 12, wherein the distance between the two consecutive holes is about 100 nm to 4000 nm. The patterned template of claim 12, wherein each of the holes has a diameter, or a width and a length dimension of about 50 nm to 3000 nm. The patterned template of claim 12, wherein the holes have a height dimension of about 200 nm to 4000 nm. The patterned template according to claim 12, wherein the template material comprises bismuth, tantalum carbide, gallium arsenide, aluminum oxide, indium phosphide, gallium nitride, germanium, antimony, nickel, aluminum or plastic. . A photovoltaic element having a patterned structure, comprising: a substrate; a first epitaxial layer over the substrate; a second epitaxial layer on the first epitaxial layer, and the second epitaxial layer a first conductivity; an active epitaxial layer over the second epitaxial layer; a third epitaxial layer over the active epitaxial layer, and the third epitaxial layer having a second conductivity; The substrate or the third epitaxial layer has a patterned structure, and the patterned structure includes a plurality of nano patterns, wherein a distance difference between each adjacent nano pattern from a center of the substrate is a certain value . The photovoltaic device of claim 19, wherein the first surface of the substrate has the patterned structure, the first epitaxial layer being formed on the first surface of the substrate and covering the pattern Structure. The photovoltaic element according to claim 19, wherein the first epitaxial layer is formed on a first surface of the substrate, and the second surface of the substrate opposite to the first surface has The patterned structure. The photovoltaic device according to claim 19, further comprising a first electrode and a second electrode respectively connected to the second epitaxial layer and the third epitaxial layer. The photovoltaic element according to claim 22, wherein the third epitaxial layer has the patterned structure, and the second electrode is located above the patterned structure. The photovoltaic element according to claim 19 is a light emitting diode, a solar cell, a photodetector, or a photodiode. The photovoltaic element according to claim 19, wherein The active epitaxial layer is a light emitting layer, and the second epitaxial layer and the third epitaxial layer are an N-type material layer and a P-type material layer. The photovoltaic element according to claim 19, wherein the nanopatterns have a circular cross section or an elliptical cross section. The photovoltaic element according to claim 19, wherein the continuous two nanometer pattern has a distance dimension of about 100 nm to 4000 nm. The photovoltaic element according to claim 19, wherein each of the nano pattern holes has a diameter, or a width and a length dimension of about 50 nm to 3000 nm. The photovoltaic element according to claim 19, wherein the nano patterns have a height dimension of about 200 nm to 4000 nm. The photovoltaic element according to claim 19, wherein the nano patterns are arranged in a spiral shape near the center of the substrate. The photovoltaic element according to claim 30, wherein the nano patterns are periodically distributed.