TW201213628A - Method for fabricating submicro patterned sapphire substrate - Google Patents

Abstract

A method fabricates a submicro patterned-sapphire substrate capable of being used in GaN light emitting diode. The method includes the following steps: forming a etching mask layer on a sapphire substrate; forming a photo resist layer on the etching mask layer; making a photo mask to contact the photo resist layer; illuminating the photo resist layer with a beam of light through the photo mask, and developing the photo resist layer to transfer a submicro pattern from the photo mask to the photo resist layer; etching the blocking layer through the photo resist layer with the submicro pattern to form a first etching mask layer; and, etching the sapphire substrate having the first etching mask layer to obtain the submicro patterned sapphire substrate.

Description

201213628 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a method for fabricating a sub-micron patterned sapphire substrate. In particular, the present invention relates to a method for fabricating a gallium nitride emitting diode. Submicron patterned sapphire substrate. [Prior Art]

The light-emitting diode is a semiconductor component that was originally used as a light source for an indicator light or a display panel. However, with the appearance of a white light diode, it is also used for illumination. Compared with the traditional light source, the light-emitting diode has the advantages of high efficiency, long life and no damage, so it is regarded as a new light source in the 21st century. When a forward voltage is applied, the light-emitting diode emits monochromatic light, and depending on the chemical composition of the semiconductor material used, the light-emitting diode emits near-ultraviolet, visible or infrared light. However, the conventional light-emitting diode is still insufficient in luminous efficiency. Therefore, in order to simultaneously improve the quantum efficiency and light extraction efficiency inside the light-emitting diode, a patterned sapphire substrate is used as a substrate for the light-emitting diode. The blue!: base t can increase the internal quantum efficiency of the erbium bond by lateral worm growth to reduce the misalignment of the gallium nitride lattice. On the other hand, the 'pattern can be limited to the illuminating-polar body (4) I(9) gemstone substrate, and the material (4) is high in the freshly extracted sputum technology. The line width applied to the gallium nitride luminescent dichroic substrate is about In the micro-level. In order to further improve the luminous efficiency 201213628 2 times micron patterned sapphire substrate has been applied to the substrate by the method of 3 times micro (four) sapphire substrate in the luminescent diode, and then the photoresist is made. The substrate is etched to obtain a micro-patterned substrate. In addition, before the photoresist is produced, it is made by the material=product method or the chemical vapor deposition method—the etching depth of the thin film layer as the sublayer and the submicron patterned substrate, so that the light has more contact area and the light is increased. Extraction rate.

Second, in the prior art, there are = methods for making sub-micron patterned substrates. The first method is to lay the nanosphere on the substrate with polystyrene = as the #刻层层, however, this method is difficult to control in uniformity, which will lead to the wafer; Another method is to form a nickel layer on the substrate as an etch stop and then anneal to self-assemble the nickel. However, this method is time consuming and does not control the uniformity of the structure. Furthermore, the step-by-step exposure method commonly used in semiconductor processes can also obtain sub-micron patterned substrates. However, this method requires expensive equipment and a machine. - The above method of fabricating a sub-micron pattern has the disadvantage that the fabricated substrate structure is not 7G, time consuming or costly, and thus is disadvantageous for the production of the submicron patterned sapphire substrate. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method of fabricating a sub-micron patterned sapphire substrate that can be fabricated in a simple and stable process to produce a substrate having a sub-micron pattern to solve the above problems. According to a specific embodiment, the method for fabricating a submicron patterned sapphire 201213628 stone substrate of the present invention comprises the steps of: first, forming a memory engraved layer on a sapphire substrate; and then forming a photoresist layer on the engraved layer Afterwards, the photoresist layer is directly contacted by the photomask; after that, the light beam is transmitted through the photomask and then the photoresist layer is developed to transfer the sub-micron pattern on the photomask to the etching layer. The micro-structured photoresist layer etches the etch stop layer to form a first etch stop layer; finally, the sapphire substrate having the first scribe layer is etched to obtain a sub-micron patterned sapphire substrate. In this embodiment, the reticle directly contacts the photoresist layer, so that the light passing through the reticle avoids diffraction and causes the scale of the structure to be too large and the uniformity to be affected. Another aspect of the present invention is to provide a method of making a sub-micron patterned sapphire substrate to solve the above problems.

According to a specific embodiment, the method for fabricating a sub-micron patterned sapphire substrate of the present invention comprises the steps of: first, fabricating a master mold having a sub-micron pattern; and then, filling a soft material into the master mold to convert a sub-module Therefore, the sub-mold will have a relative pattern with respect to the sub-micron pattern of the mother mold; the special material is filled with the m-pattern of the sub-module t; then, the sub-mold = the gem substrate is printed (four), therefore, the sub-form In the _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Substrate. In this embodiment, the submicron® sample on the photoresist layer is made of a mold having a two-stage®-like mold, thereby avoiding the diffraction layer caused by the diffraction-prevention method in the prior art. influences. The advantages and spirit of the present invention can be further understood from the following detailed description of the invention and the accompanying drawings. [Embodiment] Please refer to FIG. 1 and FIG. 2A to FIG. 2 (3. FIG. 1 is a flow chart showing the steps of a method for fabricating a sub-micron patterned sapphire substrate 3 according to an embodiment of the present invention. 2A to 2G are schematic diagrams showing the steps of the method of Fig. 1. As shown in Fig. 1, the method of the specific embodiment may include the step s1 to the step S22. In the step S10, the sapphire substrate is prepared. As shown in Fig. 2a, in step S12, an etch stop layer 32 is disposed on the sapphire substrate 3, as shown in FIG. 2B, wherein the material of the etch barrier layer 32 may be yttrium oxide or nitrided. Or bismuth oxynitride, which can be formed by general physical vapor deposition or chemical vapor deposition, such as plasma-assisted chemical vapor deposition (PECVD; Plasma Enhanced (5) such as (5)

Deposition) or high density plasma chemical vapor deposition (HDpcvD; High Density Plasma Chemicai Vapor Dep〇siti〇n) method in step S14, a photoresist layer 34 is disposed on the etch stop layer 32, as shown in FIG. . In step S16, the photoresist layer 34 is contacted with a mask μ as shown in FIG. In step S18, the exposure process is performed by irradiating the photoresist layer 34 with the light beam through the mask, as shown in FIG. 2D, and then the development process is performed on the photoresist layer to transfer the sub-micron pattern on the mask to the light. The resist layer 34 is as shown in FIG. In step S2G, the first etching layer is formed by etching the money engraving layer 32 through the photoresist layer 34 having the second micro-smear day, and then removing the photoresist layer 34, as shown in FIG. Then, in S22 201213628, the slab 30 having the first etch stop layer 32 is etched by a wet etching process to obtain the sub-micro pattern sapphire substrate 3, such as the above-mentioned wet etching process, using phosphoric acid and The nitric acid is mixed between j and 3 to the ratio of 5, wherein the temperature of the engraving is about 2 (10) to Mo.

between. Please note that in the practical towel, the user or the designer can change the sub-micron 嶋 on the mask M to change the pattern of the sub-money-like blue y stone substrate. In the specific embodiment, the method can be grown on the sapphire substrate by using physical vapor deposition (pVD) or chemical phase deposition (CVD), and can be coated by spin coating. The photoresist layer 34 is on the etch stop layer 32. Please note that in practice, the thickness of the photoresist layer 34 is as thin as possible to facilitate the fabrication of the sub-micron pattern. For example, the photoresist layer 34 may be 〇·4γηι to 〇. shame. Further, the photoresist layer 34 is coated. It should also be kept clean to prevent the gap between the two of the photoresist layer 34 from being formed by the particles on the surface of the photoresist layer 34, causing the light beam to be diffracted and affecting the line width of the submicron pattern. In the step S16, the photoresist layer 34 is directly contacted with the photoresist layer 34, and then the subsequent exposure and development process is performed. Therefore, there is no gap between the mask Μ and the photoresist layer 34. When a light beam (e.g., 365 nm ultraviolet light) is irradiated onto the photoresist layer 34 through the mask μ, the diffraction caused by the voids can be prevented from causing the line width of the submicron pattern to become large. The mask Μ is in hard contact with the photoresist layer 34. For the method of contact, please refer to FIG. 3. FIG. 3 is a flow chart showing the detailed steps of the step S16 of the method of FIG. As shown in FIG. 3, step S16 further includes step S160 and step S162. In step S160, the photoresist layer 34 is soft baked, and then, in step S162, the mask M is biased so as to be in close contact with the photoresist layer 34 by 201213628. Two states, because when the photomask is in contact with the photoresist layer 34, the photoresist is removed. In addition, the cover and the photoresist layer 34 are in close contact to each other to provide a light gap. Μ Avoiding the vacancy between the two. In a specific embodiment, the photoresist layer 34 can be removed during development, that is, the layer portion is at f. However, in practice, the photoresist layer can also be blocked by negative photoresist and is not limited. Depending on the needs of the W, the present invention f, the above-mentioned step S20, can be __ system and the photoresist layer 34 having the sub-micron pattern is illusion 2

32, causing the _ floor 32 to have a photoresist layer ^0, the side barrier layer 32 having an under-micro pattern is the first-for-scratch barrier layer, please refer to FIG. 2G, as shown in FIG. 2G, step S22 The sub-micron patterned sapphire substrate 3 is obtained by etching the sapphire substrate 3 with the barrier structure 36 as a germanium layer and using a wet etching process. Since the wet etching process immerses the entire substrate in the etching solution for etching, the etching of the sapphire substrate has a certain degree of isotropic. In other words, the submicron patterned sapphire substrate 3 is etched according to the etching liquid used. The size of the pattern etched by the space may be greater than or equal to the size of the sub-micron pattern of the first etch stop layer 320. However, by the hard mask of step S16 and the photoresist layer 34 201213628 to avoid the diffraction phenomenon, the size of the sub-micron pattern of the first residual layer 32 can be controlled and the sub-micron patterned sapphire substrate 3 can be indirectly controlled. The size of the pattern A on it is maintained at the sub-micron level. On the other hand, as shown in FIG. 1G, the two etched portions (pattern A) on the sub-micron patterned sapphire substrate 3 can also be regarded as another sub-micron pattern B, since the etching liquid will have different degrees. Isotropic, so the size of the pattern B can easily reach the sub-micron level. In addition, in this embodiment, step S22 further removes the first surname barrier layer 320 after etching the sapphire substrate 30 to obtain the sub-micron patterned sapphire substrate 3, and is fabricated by the method of the specific embodiment. The sub-micron patterned sapphire substrate 3 can be directly used in a gallium nitride light emitting diode. The above specific example is to stencil the sapphire substrate by wet etching, so that the etched submicron pattern has a certain degree of isotropic. However, the method of the present invention can also etch a sapphire substrate by dry etching. ... See Figure 4A, Figure 4B, and Figure 4c. Figure 4A is a flow chart showing the steps of a method of fabricating a sub-micron patterned sapphire substrate 6 in accordance with another embodiment of the present invention. Figure 4B is a schematic diagram showing the step S50 of the method of Figure 4a. Figure 4C is a schematic view showing the sub-micron patterned sapphire substrate 6 produced by the method of Figure 48. As shown in FIG. 4A, the specific embodiment is different from the above specific embodiment, and the method of the specific embodiment includes step S5G and step S52. In step S50, (4) the photoresist layer 62 is transferred through the photoresist layer 64 having the sub-micron pattern, the photoresist layer 64 having the sub-micron pattern, and the side barrier layer 62 having the engraved name of 201213628. As shown in FIG. 4B, in: S52, the sub-micron patterned blue sapphire substrate 6 having the barrier plate shown in Fig. 4 is etched by a dry etching process, wherein the dry etching can be performed with an induced entangled m 〇 > UPled PIasma ) or anti-ship ion _ ' =1Ve !. Hing). It should be noted that since the other steps of the method of the specific embodiment are substantially the same as the steps corresponding to the above specific embodiments, the details are not described herein. The isotropic dry sculpt method produces a human micro = patterned sapphire substrate 6, so the cross-sectional view is as shown. In the practical towel, dry can be, but not new, electric spare time. Similarly, since the reticle of the present embodiment and the sub-micron pattern of =! can be directly transferred to the photoresist layer to have a barrier structure with a sub-micron pattern. Since the barrier structure 66 is a silver engraved layer 62 plus the thickness of the photoresist layer 64, by blocking =. 66 can be engraved with a deeper submicron structure patterned sapphire base. In addition, the anisotropic remnant and the collision structure of the dry side process can make the sapphire substrate have a submicron pattern. In the specific embodiment, the photomask is directly contacted with the photoresist layer disposed on the sapphire substrate, and then the exposure and development process is performed, so that the sub-micron pattern on the photomask is transferred to the photoresist layer and the side layer to form a second time. Micron pattern engraved layer or barrier structure. By having the sub-micron pattern of the surname: the second resistive structure, the sub-micropatterned sapphire substrate can be easily completed by a dry rice or wet residue process. Compared with the prior art, the reticle directly connected to the ri 11 201213628 touch photoresist layer can avoid the occurrence of diffraction during exposure and affect the line width of the second micro pattern. In addition, the process of this method can be used in Huang Guangwei. The shadow process end achieves the production of sub-micron patterns', thus having the advantages of shortening process time, good structural uniformity and low cost.

Referring to FIG. 5 and FIG. 6A to FIG. 6G, FIG. 5 is a flow chart showing the steps of the method for fabricating the sub-micron patterned sapphire substrate 8 according to another embodiment of the present invention, FIG. 6A to FIG. 6g. A schematic diagram showing the steps of the method of FIG. As shown in FIG. 5, the method of this embodiment may include steps S7 to S78. In step S70, a master 90' having a sub-micron pattern 9' is produced as shown in Fig. 6A. Then, in step S72, the soft material is injected into the master mold 90 to reproduce a sub-module 92, wherein the sub-module 92 cooperates with the master mold 90 to have a relative pattern 92 with respect to the sub-micron pattern 900, as shown in FIG. B and Figure 6C. Thereafter, in step S74, the imprint material is filled and filled into the opposite pattern 920 of the sub-mold 92, as shown in FIG. Thereafter, in step S76, the sapphire substrate 8 is imprinted by the sub-mold 92 (the embossed material 84 is formed on the sapphire substrate 8G to form the photoresist layer 82, and the photoresist layer 82 has a sub-micron pattern with the master 90. The same pattern is continued as shown in Fig. 6E and Fig. 6. Finally, in step S78, the sapphire substrate 80 is side-processed through the f-resist layer 82 to obtain a sub-micron patterned sapphire substrate 8, as shown in Fig. 6G. In the present embodiment, the 'female mold 90 can be, but is not limited to, Shi Xi composition.> In addition, in practice, the sub-micron pattern can be formed on the side mold 90 of the electron beam or the exposure machine. The soft material used to form the sub-mold 12 201213628 92 may be, but is not limited to, polymethyl phthalocyanine (PDMS) in this embodiment. In addition, the perfusion is filled in the sub-form. The imprint material in the relative pattern 920 of the mold 92 can be, but is not limited to, polymethyl methacrylate (PMMA) in the specific embodiment. Like the above specific embodiment, the specific embodiment The sapphire substrate 8〇 can also be carved through the money Wet lithography process name is read to obtain a paste-like reduction of the sapphire plate 8, the difference between the two other contact lithography process wherein j Yun engraved based dry anisotropic wet classification rather than engraved engraved based isotropic moment I,

In the practice, the above two types can be arbitrarily selected by the user or the demand of the two users. The present invention is not limited thereto. Therefore, by the method of the present embodiment, the photoresist layer can be formed through the mold to form a submicron pattern and disposed by direct contact. Since the photoresist layer does not need to pass through the exposure method of the prior art, it can avoid the shadowing of the sub-micron pattern of the photoresist layer by the diffraction county. The same method of making the photoresist layer is the same as the method of making the photoresist layer, which can avoid the disadvantages of the time-consuming or cost-oriented technology of the pioneer.

The right sapphire substrate has a etched barrier layer, and the above method can firstly etch the secondary layer and pass through the process with the sub-micron structure to obtain the sub-micron patterning: and FIG. 8A to FIG. 'Figure 7 is shown according to this section: Example of the production of sub-micron patterned sapphire substrate 8 === Figure: Figure VIII to Figure 8 (four) Green diagram 7 is not intended. Note that the etch stop layer 800 is further included in the sapphire substrate 201213628 80 of the present embodiment. As shown in FIG. 7, the specific embodiment is different from the previous embodiment in that the method of the specific embodiment further includes steps S76〇, s78〇, step+S782, and step S784. In step S76, the sapphire substrate 8Q is imprinted by the sub-mold 92 and the imprint material μ is formed on the sapphire film 80. Similarly, the photoresist layer 82 has a sub-micron pattern with the master mold 90. 9〇〇 The same pattern, as shown in Figure 8 and Figure 8-2. In step S78, the photoresist layer 82 having the sub-micron pattern is transferred to transfer the second micro-pattern on the photoresist layer 82, as shown in FIG. In the step pass, remove the light D as shown. Finally, in the step reading, the sub-micron patterned sapphire substrate 8 is obtained by etching the sapphire substrate 80 with 裎2 layers 8〇0, as shown in FIG. 8e: the method of the present embodiment is The other steps are the same as the above-mentioned specific steps; the corresponding steps are generally in the same, and therefore will not be described here. In this embodiment, after the sub-micron pattern to the money engraving layer 8GG, the silk layer 82 is transferred to the seventh layer. The sound 800 ship #卩 is removed and etched only through the etch stop f: 丄 substrate 8 。. However, in another embodiment, the photoresist layer can also be retained and the etch stop can pass through the barrier structure. The sapphire substrate enters (four) into the sapphire substrate. Therefore, whether the photoresist layer is retained or not can be inspected according to the user's above-mentioned production of the sub-micron _ gemstone substrate 201213628 Directly contacting the photoresist layer on the sapphire substrate and exposing it to form a sub-micron structure on the surface of the ruthenium; or directly forming a photoresist layer having a structure of ym and directly imprinting it on the sapphire substrate. The method of the invention can avoid dimming during exposure Shadow 2: The method of making the photoresist layer accurately develop the desired sub-micron pattern. The sub-micro-reversed sapphire substrate can be obtained by the sapphire substrate side of the human micro-pattern. Get this.

The legal system can avoid the prior art consumption of P + 2 or more. The details of the details can be more clearly understood. The characteristics and spirit of the present invention can be more clearly understood than the preferred embodiment of the present invention. The material of the invention is purely closed. In the case of land reduction, it is intended to cover the scope of patents of various changes and equal arrangements. Therefore, the specific mouthpieces of the present invention should be interpreted broadly according to the above description, with all possible variations and arrangements of equivalence. Total 盍

15 201213628 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing the steps of a method for fabricating a r-micron patterned sapphire substrate in accordance with an embodiment of the present invention. Figure 2A to Figure 2G show the steps of the method of Figure 1 _ J Hui.

3 is a flow chart showing the detailed steps of the photomask contacting photoresist layer of the method of FIG. 1. FIG. 4A is a flow chart showing the steps of a method for fabricating a submicron patterned sapphire substrate according to another embodiment of the present invention. Figure. Figure 4B is a schematic diagram showing the step S50 of the method of Figure 4A. Figure 4C is a schematic view showing a sub-micron patterned sapphire substrate produced by the method of Figure 4A. Figure 5 is a flow chart showing the steps of a method of making a sub-micrometer patterned sapphire substrate in accordance with another embodiment of the present invention. Figures 6A through 6G show the sound maps of the steps of the method of Figure 5. Figure 7 is a flow chart showing the steps of a method of making a sub-micrometer patterned sapphire substrate in accordance with another embodiment of the present invention. Figures 8A through 8E are pictorial diagrams showing the steps of the method of Figure 7. 16 201213628 [Description of main component symbols] S10~S22: Process steps 3, 6: Sub-micron patterned sapphire substrate 30, 60: sapphire substrate 32, 62: etch stop layer 34, 64: photoresist layer 320: first etch stop Layers A, B: Patterns S160 to S162: Flow Steps S40 to S52: Flow Steps S70 to S78: Flow Step 66: Block Structure S760, S780 to S784: Flow Step 90: Master Model 900: Submicron Pattern 92: Submodule 920 : Relative pattern 80: sapphire substrate 800: etch stop layer 82: photoresist layer 84: embossed material 8: sub-micron patterned sapphire substrate 17

Claims (1)

201213628 VII, 2, 3, Scope of application: = method of seeding, sub-micron patterned sapphire substrate, using - human micro-pattern - sub-micron patterned sapphire substrate ^ The following steps are included: Method for forming a sapphire substrate a photoresist layer; a photoresist layer is formed on the etch barrier layer; the photomask layer is contacted by the reticle having the submicron pattern; and the light beam is transmitted through the reticle to transmit the photoresist layer The photoresist layer on the photomask and the m-th micro-pattern of the mask is etched to form the first veneer layer; and the eta field is etched to etch the sapphire pattern having the first etch stop layer Sapphire substrate. In order to obtain the method described in the patent application, the method further comprises the following steps: softly baking the photoresist layer and then contacting the photoresist layer with the photomask. The method of claim 1, wherein the beam is an ultraviolet light, and the method of claim 1 is as follows: the step comprises the following steps: forming the i-th engraving, moving _ Photoresist layer. 5. The method of claim 4, further comprising the following steps: 18 201213628 etching the sapphire base having the first etch stop layer by a wet etching process. 6, 2, please patent (4)! In the method described, the step further comprises the step of forming the first remaining layer of the fish to form a barrier structure by the photoresist layer of the rice structure. ..., there are ^ people 7, the method described in item 6 of the scope of interest, the following steps include the following steps to make a miscellaneous y stone substrate with the structure. 8. The method of claim 4, wherein the physical vapor deposition process is formed on the substrate. The staging layer is a 9' other grade to transfer the coating layer to the spin, and the second method, the tool comprises the following steps (4) to form a blue f stone substrate, the method will be ι=:=Τ The second micro_material builds Ke 19 201213628 The formation of the _ fine layer 'fine material has the micro-transmission through the photoresist layer to the sapphire substrate sapphire patterned sapphire substrate. The method of claim 5, wherein the sapphire dt-, the barrier layer and the photoresist layer are disposed on the remaining S layer, the method further comprises the following steps : the photoresist layer having the submicron pattern is left to transfer the submicron pattern to the etch stop layer; and the == microstructure structure of the sapphire substrate is processed to obtain the process This time, the sapphire substrate is patterned. yPlease take the _12 item of the township, and the following steps include the following steps: after removing the micro sample to the _ barrier layer, remove the photoresist. 14. The method described in claim 11 (4) Step: 豕 further includes the following steps: - etching the sapphire substrate to obtain the sub-micron pattern ^ the method described in the scope of claim u, who further includes the following steps: Λ 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该The method of claim 11, further comprising the step of: fabricating the master by an electron beam etching method. 17. The method of claim 11, further comprising the step of: fabricating the master by an exposure machine etching process. twenty one