TW590980B - Micro-optical element and fixture thereon and method of manufacturing above two - Google Patents

Abstract

A micro-optical element and fixture thereon and method of manufacturing above two are provided. The structure consists of a Si substrate, two protection layers, and a thin film optical element, wherein the Si substrate has an opening. These protection layers is located on the surface of the Si substrate. The thin film optical element is located on the opening of the Si substrate. Because the micro-optical element and fixture thereon are manufactured by bulk micromachining and an absorptivity of a material of the thin film optical element is lower than that of polysilicon in wavelength region of visible light, it can improve optical efficiency.

Description

590980 --- new 92Π3562_year month said to work__ V. Description of the invention (1) " The technology to which the invention belongs j. The field This invention relates to a micro-optical element and its holder and production The invention particularly relates to a method for manufacturing a micro-optical element and a clamping device thereof using semiconductor micro-electromechanical technology. The previous technology of micro-optoelectronics in recent years basically uses the existing micro-package technology of the semiconductor industry, coupled with some micro-silicon processing technologies, combining optical components and systems on the same chip as integrated circuits can be regarded Photoelectric integrated circuit. Its advantages are small size, low cost, light weight, and avoiding alignment technology in optoelectronic systems. Not only the system is simplified, but reliability and life can be improved. Its manufacturing technology can also use existing semiconductor equipment without double investment. The conventional micro-silicon is separated on different surfaces by known micro-micro-layers. The surface-transmission method can be used to form a crystal crushing process and the "surface sacrificial layer is successfully produced." The seed film is mostly described in 1C Layer and sacrifice substrate technology The most commonly used micro-silicon processing technology for micro-optoelectronic systems is the so-called surface micromachining, which uses the mechanical structure deposited in the process in the case of damaging Shi Xi substrates. The most representative one is the processing method II. Due to the high processing technology of polycrystalline sand surface microlithic slab, it quickly gained the favor of the industry, government, and academia. : The manufacturing method of all parts and their fixtures is to use the feeding technology. The process is mainly to use the component structure τ selective # etch (). Z structure layer, and the specific part of the element structure layer and = Refer to Figure 1, which is a schematic diagram of the structure of an optical element that is conventionally processed from surface micro silicon.

Page 11 590980 __Serial No. 92113562_ year, month, day, date, revision_ 5. Description of the invention (2) Please refer to Figure 1, the micro-optical element 1 0 0 produced by surface micro silicon processing technology is mainly composed of a silicon The substrate 10, 2, a light source 104, a transmissive element structure 106, and a reflective element structure 108. The configuration is that the light source 104 is disposed on the substrate 102, and the transmissive element structure 106 and the reflective element structure 108 are formed on the substrate 102 and are adjacent to the light source 104. And 'Since the element structures 106 and 108 are produced by the surface microlithic processing technology, it can be seen from the first figure that the structure stands on the substrate 102 and is partially suspended in the air. . After the light 1 10 is emitted from the light source 104, it will be reflected by the transmissive element structure 106 'and then reflected by the reflective element structure 108. However, because the surface micro-silicon processing technology is more difficult to control than the general C process, and the conventional surface micro-silicon processing technology needs to use isotropic etching if it is to produce a floating microstructure like 1 in Figure i. . In order for the liquid to penetrate into the element structure layer smoothly, it is usually necessary to make a lot of extra etch holes in the element structure ^. But in the field of optics, Qian Yue window will undoubtedly reduce the optical quality of micro-optical components. In addition, the structure of the device made by the planar microlithic slab / processing technology is mostly polycrystalline slab, and the polycrystalline slab has extremely high absorption in the visible wavelength range, which is very unfavorable for visible optical applications. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a micro-optical device and a method for manufacturing the two in order to simplify the manufacturing process. 8. Another object of the present invention is to provide a micro-optical element and a clamping device thereof, and a method for manufacturing the foregoing two, so as to improve optical efficiency. A further object of the present invention is to provide a micro-optical element and its holding tool

590980 _Case No. 92113562_ Years and months Amendment _ V. Description of the invention (3) and the method of making the above two, so as to achieve a micro-optical element with a vertical optical axis. According to the above and other objectives, the present invention proposes a micro-optical element and a holder thereof, the structure of which is composed of an open silicon wafer, two protective layers, and a thin-film optical element. Among them, the protective layer is disposed on the surface of the silicon wafer, and the thin-film optical element is placed on the silicon wafer opening. The invention further proposes a method for manufacturing a micro-optical element and a clamping device thereof, which includes providing a silicon wafer, and usually the silicon wafer has a front surface and a back surface. Then, a deposition layer is formed on the front surface of the silicon wafer, and the material of the deposition layer needs to have a higher absorption rate in the visible wavelength range than crystalline silicon, and then a protective layer is formed on the back of the silicon wafer. Subsequently, a protective layer is defined to form a first opening, and the back of the silicon wafer is exposed. Then, a deposition layer is defined to form a micro-optical element, and the first opening is used as a mask to completely remove the exposed silicon wafer to form a second opening. In the present invention, since a micro-optical element processing technology (bu 1 k micromachining) is used to fabricate a micro-optical element and its holder, there is no need to open a lot of #etched holes in the element structure layer, thereby avoiding the low optical efficiency caused by the conventional knowledge. problem. In addition, the present invention adopts a material having a higher absorptivity in the visible light wavelength range and a lower crystalline silicon as the material of the micro-optical element, such as silicon nitride, silicon oxide, and its family, so the micro-optical element of the present invention can be applied to the visible light wavelength range. In addition, since the structure of the micro-optical element and the holder of the present invention can directly transmit light through the micro-optical element, it can be a micro-optical element with a vertical optical axis. In order to make the above and other objects, features, and advantages of the present invention clearer

10667twf2.ptc Page 13 590980 _ Case No. 92113562 V. Description of the invention (4) The correction is easy to understand. The following is a detailed description of the preferred embodiment and the accompanying drawings, as follows: Implementation Figure 2 A schematic cross-sectional view of a micro-optical element and a holder thereof according to a preferred embodiment of the present invention. Please refer to FIG. 2. The structure of the micro-optical element and the clamping device of the present invention is composed of a silicon wafer 200 with an opening 202, two protective layers 204, and a thin-film optical element 206. composition. The arrangement of the aforementioned components is that the protective layer 202 is disposed on the surface of the silicon wafer 200, and the thin film optical element 2 06 is placed on the silicon wafer 2 0 0 opening 2 0, of which the thin film optical element 2 0 6 The material needs to be a material with a low absorptivity in the visible wavelength range, such as silicon nitride, silicon oxide, and its family. In addition, the thickness of the silicon wafer 2000 is, for example, 300 micrometers, and the crystal orientation thereof is, for example, <100>. The included angle of the opening 200 2 of the silicon wafer 2000 may be 54.74 degrees, and the size of the opening 202 may be, for example, between 300 μm and 5000 μm. In addition, the surface of the opening 202 may be a reflecting mirror, and in order to improve the reflectivity, a layer of a highly reflective film may be added to the surface of the opening 202. Please continue to refer to FIG. 2. The material of the protective layer 204 is, for example, the same material as that of the thin-film optical element 206, such as silicon nitride, silicon oxide, and its group. The thin film optical element 206 in the present invention may be a grating for splitting a laser beam, a fresne 1 lens with focusing function, a quarter wave plate for changing polarization characteristics, and a half wave plate for changing polarization characteristics. , Micro lenses or micro lens arrays with focusing function, holograms, diffractive optical elements, etc. Figures 3A to 3E below are micro-optical 1 screens according to a preferred embodiment of the present invention. __ 议 11 Draw band 1 | __ | _1 骊 _ ___Circle 1 10667twf2.ptc Page 14 590980 _Case No. 92113562__Yueyueyue Amendment__ V. Description of the Invention (5) A cross-sectional view of the manufacturing process of the component and its sandwich. Referring to FIG. 3A, a silicon wafer 300 is provided, which has a front side 3101 and a back side 3303. Then, a deposition layer 302 is formed on the silicon wafer 300 front side 3 01, wherein the material of the deposition layer 302 has a higher absorption rate in the visible wavelength range than crystalline silicon, such as silicon nitride, silicon oxide, and its groups. Then, a protective layer 304 is formed on the silicon wafer 300 on the back surface 300, wherein the material of the protective layer 304 includes silicon nitride. In addition, the step of forming a deposition layer 3 2 on the silicon wafer 3 0 front 3 0 1 or forming a protective layer 3 4 on the silicon wafer 3 0 0 back 3 3 is, for example, a low pressure vapor deposition process (LPCVD) or electrical Pulp vapor deposition process (PECVD). Then, please refer to FIG. 3B to define the protective layer 304. The detailed process is described as follows. A photoresist layer 306 is formed on each of the deposited layer 3202 and the protective layer 304. The photoresist layer 306 For example, the photoresist of AZ 1500 has a thickness of about 2 microns. In addition, before the photoresist layer 306 is formed, a solution containing Hexamethyldisilazane (HMDS) is coated on the protective layer 304, the deposition layer 302, and the protective layer 304 to increase the photoresist and the silicon substrate. Adhesiveness. Then, a lithography process is performed to pattern the photoresist layer 306 adjacent to the protective layer 304. The lithography process, for example, sequentially performs a soft baking process, an exposure process, and a development process, and needs to be performed in the subsequent etching process. A hard roasting process. After that, the photoresist layer 300 is used as a mask, and an etching process is performed on the protective layer 300 to form a first opening 300, and the back surface 303 of the Shixi wafer 300 is exposed. It can be an inductive light and electropolymerization (ICP) dry etching process' or it can be a wet etching process. When the etching process is a wet etching process, an etching solution such as β hydrofluoric acid (HF) or buffered hydrofluoric acid (BHF) is used. ^ ^

10667twf2.ptc Page 15 590980 Case No. 92113562 V. Description of the Invention (6) Next, Yan Qing performed another lithography process with reference to Figure 3C to pattern the photoresist layer 3 0 6 adjacent to the deposited layer 3 0 2, For an implementation example, refer to FIG. 3B. After the patterned photoresist layer 3 06 has been formed with the pattern of the micro-optical element 3 07 ', the photoresist layer 306 adjacent to the protective layer 3 04 is removed. Then, referring to FIG. 3D, using the photoresist layer 3 04 as an etching mask, an etching process is performed on the sunk layer 3 02 to form a micro-optical element 31 (), wherein the touch-etching process may be induction consumption The combined plasma dry etching process may also be a wet etching process. When this etching process is a wet etching process, the remaining etching solution used therein is, for example, hydrofluoric acid or buffered hydrofluoric acid. The photoresist layer 306 adjacent to the deposited layer 302 is then removed to complete the step of defining the deposited layer 302. Then, please refer to FIG. 3E 'with the first opening 3 08 as a mask, completely removing the exposed Shixi wafer 300' to form a second opening m2, wherein the step of forming the second opening 3 1 2 includes using A selective etching process is performed with a bell hydroxide (κ η). In addition, assuming that the crystal orientation of the silicon wafer 300 is <丨 00>, the opening size 313 of the first opening 308 is 5000 μm, and the thickness of the silicon wafer is 5000 μm, the second opening 3 1 2 is formed by etching. The minimum dimension 3, 5 is about 4,000 microns, and the crystal orientation of the second opening 3 12 is <1 1>. The included angle of the opening 312 of the Shixi wafer 3,00 may be 54.74 degrees. In the present invention, since the micro-optical element processing technology (bu 1 k micromachining) is used to fabricate the micro-optical element and its holder, there is no need to open a lot of extra holes in the element structure layer, thereby avoiding the low optical efficiency caused by the conventional knowledge. problem. In addition, the present invention uses more absorption in the visible wavelength range.

10667twf2.ptc Page 16 590980 _Case No. 92113562_Year Month Revision_ V. Description of the invention (7) Materials with low crystalline silicon are used as materials for micro-optical components, such as silicon nitride, silicon oxide, and their families, so the present invention The micro optics can be used in the visible wavelength range. In addition, because the structure of the micro-optical element and the holder of the present invention can directly transmit light through the micro-optical element, a micro-optical element with a vertical optical axis can be achieved. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

10667twf2.ptc Page 17 590980 _Case No. 92113562_ Years and Months Revision _ Brief Description of Drawings Figure 1 is a schematic diagram of the structure of a micro-optical element and its holder made by conventional micro-silicon processing technology; FIG. 2 is a schematic cross-sectional view of a micro-optical element and a clamping device according to a preferred embodiment of the present invention; and FIGS. 3 A to 3 E are micro-optical elements according to a preferred embodiment of the present invention. A cross-sectional view of the manufacturing process of the component and its clamping. Graphical description 100 micro-optical elements 102 silicon substrate 104 light source 106 transmissive element structure 108 reflective element structure 110 light 200, 300: silicon wafer 2 0 2, 3 0 8, 3 1 2: opening 2 0 4, 3 0 4: Protective layer 2 0 6, 3 1 0: Thin film optical element 301: Front surface 303: Back surface 3 0 2: Deposited layer 3 0 6: Photoresist layer 307: Pattern 313, 315: Size

10667twf2.ptc Page 18

Claims (1)

590980 Case No. 92113562_Year_Month_Amendment VI. Application scope 1. A holder for a micro-optical element includes: a silicon wafer having at least one opening; two protective layers disposed on the surface of the silicon wafer; and At least one thin-film optical element disposed on the at least one opening of the silicon wafer. The angle of the at least one opening of the silicon wafer in the holder of the micro-optical element as described in item 1 of the patent scope is requested. It is 5 4. 7 4 degrees. 3. The micro-optical element and its holder as described in item 1 of the patent scope, wherein the surface of at least one opening σ is a reflecting mirror with a reflection function. The clamping device of the micro-optical element mentioned above further includes _ a retroreflective film is located on the surface of the mirror to improve the reflectance. The opening size of the at least one opening of the silicon wafer is between 300 μm and 5000 μm. As described in the patent scope of claim 1, the holder of the micro-optical element is provided with the protective layer. The material includes silicon nitride. 7. As claimed in the patent scope: The micro-optical element clamping device described in item 1, wherein the material of the at least one thin-film optical element has a higher absorption rate in the visible light wavelength range than crystalline silicon. 8 The clamping device of the micro-optical element according to item 5, wherein the material of the at least one thin-film optical element includes silicon nitride, silicon oxide, and one of its groups. 10667twf2.ptc Page 19 590980 _Case No. 92113562_Year Month Amendment __ Sixth, the scope of patent application 9. The holder of the micro-optical element as described in the first scope of the patent application, wherein the at least one thin-film optical element Includes a thumb that splits the laser beam. 10. The clamping device for a micro-optical element according to item 1 of the scope of patent application, wherein the at least one thin-film optical element includes a fresnel lens having a focusing function. 1 1. The holder of the micro-optical element according to item 1 of the scope of the patent application, wherein the at least one thin-film optical element includes one of a quarter wave plate and a half wave plate which changes polarization characteristics . 1 2. The holder of the micro-optical element according to item 1 of the scope of patent application, wherein the at least one thin-film optical element includes one of a micro lens and a micro lens array having a focusing function. 1 3. The holder of the micro-optical element according to item 1 of the scope of the patent application, wherein the at least one thin-film optical element includes a hologram. 1 4. The holder of the micro-optical element according to item 1 of the scope of patent application, wherein the at least one thin-film optical element includes a diffractive optical element. 15. A method for manufacturing a clamping device for a micro-optical element, comprising: providing a silicon wafer having a front surface and a back surface; forming a deposition layer on the front surface of the silicon wafer, wherein the material of the deposition layer is Absorptance in the visible wavelength range is more low than crystalline silicon; forming a protective layer on the back surface of the silicon wafer; defining the protective layer to form a first opening and exposing the back surface of the silicon wafer; defining the deposition layer To form a micro-optical element; and 10667twf2.ptc Page 20 590980 _Case No. 92113562_Year Month Amendment __ VI. Scope of Patent Application The first opening is used as a mask to completely remove the exposed silicon wafer to form a second opening. 16. The method for manufacturing a micro-optical element as described in item 15 of the scope of the patent application, wherein the material of the deposited layer has a higher absorption rate in the visible wavelength range than that of spar. 1 7. The method for manufacturing a micro-optical element holder as described in item 15 of the scope of patent application, wherein the material of the deposited layer includes silicon nitride. 1 8. The method for manufacturing a micro-optical element holder as described in item 15 of the scope of patent application, wherein the material of the protective layer includes silicon nitride. 19. The method for making a clamping device for a micro-optical element according to item 15 of the scope of patent application, wherein the step of defining the protective layer includes: forming a photoresist layer on the protective layer; performing a lithography process, Patterning the photoresist layer; and performing an etching process on the protective layer, the etching process uses the photoresist layer as an etching mask. 2 0. The method for manufacturing a micro-optical device as described in item 19 of the scope of patent application, wherein before forming the photoresist layer on the protective layer, it further comprises coating the protective layer with A solution of methyldisilazane (HMDS) to remove Si-OΗ bonds in the protective layer. 2 1. The method for manufacturing a micro-optical element as described in item 19 of the scope of patent application, wherein the thickness of the photoresist layer is about 2 microns. 2 2. The method for manufacturing a micro-optical element holder as described in item 19 of the patent application scope, wherein the etching process includes an inductively coupled plasma (I CP) dry etching process. 10667twf2.ptc Page 21 590980 Case No. 92113562 Item No. 9113562 mentioned in the revised version of Yuan Xueguang's micro-production system 9 11 No. Fan Li specially invited Zhong Wei as a fan girl 13 · Please 2 apply for six methods · 4 J 2 set The engraving process of wet etching and enclosing process is described in the above. The element is described in the elementary optical micro-production system. 3 2 Fan Li specially invites the use of such as the fluorine nitrogen encapsulation solution engraving 0 to use the process JF Η Η Β (Β This acid has fluorine and its hydrogen * ι ^ .Ν, the phase method is eased, JL (} 5 J / F 2 set (Η Light micro work. The layer before the item in the description of the system protects the definition. The layer, the method of blocking the light side, is shaped, and the 26 layer is placed on the middle layer to accumulate and cover the fan. The application of Yuan Ruguang's microfabrication is more soluble. Λ-ο \) y, the DJ Μ layer of January S, alkane phosgene, which is formed on the silicon layer in a dimorphic base. Shen contains the one coated on the cloth. The middle layer of the cool package should be removed. It should be made by Yuan Xueguang with 7 2 fluids. Fan Li specially requested the application of Yuan Xueguang. The above-mentioned items in the key block should be blocked by: Step by step, the resistance of the layer of light, accumulate the process of Shenhua to make the case carved definition map # Set one in the middle, go through the process, and make the layer. The eclipse 28 is a piece of interlayer that is described by Yuan Xueguang, which is described in item 7 2. Fan Li specially asked for the middle piece. Yuan Yuanxue, Zuo Guangmi, made 2 in the thick layer and 2 In the 5th chapter of the book, J-Kao Qibiao 1 requesting the application of the 29 sets of folders described in the above description should be included in the process of etching, etc. ο the law of the formula system Set-up method of drying • 30 sets of set-ups described in Yuan Xueguang's micro-manufacturing system 7 2 No. 4 Guili special invites Zhongrucheng to etch wet encapsulation system to etch the middle I 10667twf2.ptc Page 22 590980 _ Case No. 92113562 _ Month and Day __ VI. Patent application scope 31. The method for making a micro-optical element as described in item 30 of the patent application scope, wherein the etching The etching solution used in the process includes one of hydrofluoric acid (HF) and buffered hydrofluoric acid (BHF). 32. The method for manufacturing a micro-optical element holder according to item 15 of the scope of patent application, wherein the step of forming the second opening includes a selective etching process using potassium hydroxide. 3 3. The method of manufacturing a micro-optical element holder according to item 15 of the scope of the patent application, wherein the step of forming the deposition layer on the front surface of the silicon wafer includes a low pressure vapor deposition process (LPPCD). 3 4. The method for manufacturing a micro-optical device as described in item 15 of the scope of patent application, wherein the step of forming the deposition layer on the front surface of the silicon wafer includes a plasma vapor deposition process (PECVD). 10667twf2.ptc Page 23