TW400537B - Method for manufacturing miniaturized device having corrugated diaphragm - Google Patents

Abstract

The invention provides a method for manufacturing miniaturized device having corrugated diaphragm, which utilizes different etch-back step to fabricate mini-circular corrugated diaphragm in one silicon chip for being used as a movable electrode plate, and the fixed electrode plate is composed of the aluminum film formed by thermal evaporating on a glass plate. Then, two electrode plates are joined to make the micro device, which could be applied in the fabrication of, for example, an actuator or the high sensitivity pressure gauge (capacitance typed) to achieve the benefit of lowering the manufacturing cost and the process time, and increasing the quantity in production and yield.

Description

V. Description of the invention (1) [Scope of the invention] The present invention relates to a method for manufacturing a micro-component with a wrinkled film, and particularly relates to a micro-round wrinkled film as a moving electrode, which is heated on a glass plate. "Evaporation film as a fixed electrode to produce a static method", Dagger 10 [Background of the Invention] In recent years, microelectronic machinery has been developed in various ways and applied to a variety of different fields. Micro actuators for micro-pump devices. There are many types of micropump actuation theories, such as the use of piezoelectric (We — zoelectric), air thermodynamic (thermopneumatic), fluid electrodynamic (electrohydrdynamic), electrostatic (Electr0-static) and electrochemical (electr0chemical) and other methods' among them, electrostatic actuators have the characteristics of other types of actuators are less affected by temperature and easier to manufacture. Generally speaking, the 'electrostatic type micro-device is driven by electrostatic forces that are attracted to two parallel electrode plates and attract each other. It is known from the past literature that when the mechanical structure of a micro-device involves a mechanical element with a large amount of deformation, it is often seen that a pleated film is used as one of the main core designs. Because the stress and strain of the wrinkled film are relatively uniform (linear), there will be no stress concentration. Its structure also has higher mechanical sensitivity than the general flat film; that is, the components are under the same load. Wrinkled film will produce a large change in deflection, which is a necessary feature of many micro-components. Therefore, for a mobile electrode of an electrostatic actuator,

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V. Description of the invention (2) 'Even other actuators or other micro-valves, pumps, pressure sensors, accelerometers and other micro-components can see the application of the wrinkle film theory, please refer to the "ACTUATORS" period and The micro formed by Dynamic with p + S i1i is about 4 5 0 β m and the depth is about 2 0. The folds 1 4 of the groove 12 are made of potassium hydrogen acid. This 0, the two electrodes are connected to the component after the substrate 2. However, the circle of (1) to learn the production rule-active I on engraved the wrinkle depth Figure 1 ", which was published by Yang et al. In " SENSORS & Publication A50 (1995) P15, 156, " Fabrication Testing of Electrostatic Actuators con Diaphragms ", a flow chart about the use of wrinkled thin film elements. As shown in "Figure 1", it is preceded by a thick Shi Xi wafer On 10, the groove 12 'defined by the EPW etching solution is used as the area for forming the thin film; then the (K0H) solution' uses anisotropic etching and etching technology to define a depth of about 4 # m in the film area. Figure 2 ", and then a diffusion system After adding boron to the wrinkles 14; please refer to "Figure 3" to etch the back of the silicon to form a wrinkle film 丄 6 to complete the mobile power by: 4 "Provide a glass substrate 20 to form a shawl The film 22 is used as a fixed electrode. The process of forming the microstructure as shown in FIG. 5 has the following disadvantages: It is known that the wrinkles are formed by anisotropic etching. , Ca n’t be used as enemy etiquette <,-Principles using active ions ^

Etching, RiE) 圚 Gu, J (Re) round wrinkle technology, w is about 1 0 # m for example, may respect Hong Lu Ji ~ J this takes several hours to dozens

'Explanation of the invention (3) hours, the process time is too long; when the cost is high, the high-energy R I roll and the cost of the R 1 E process equipment are too high. The sigh may cost tens of millions of dollars, so the part of the process (2) "Figure 2" of the step of engraving the Shi Xi wafer can only be engraved and the etching angle, which is about 54.7. The groove pleats the film at the relative position. There is enough space between the electrode and the electrode to reduce the number of wrinkle films. The area where the wrinkle film is formed will be limited. The wrinkles of T need to be etched on the back side by forming a wrinkle film on the back side as shown in Figure 3 When the surface is formed with an included angle (0 ^ shown in "Figure 3", the recesses originally formed in "Figure 1" must be kept at an appropriate distance "so that the sensitive aluminum electrodes can be joined and the wrinkles are thin after joining.臈 and gaps, but in this way can be formed on the silicon wafer, 疋 疋, Shi Xi wafer can be used as a sensor can not be improved, so of course the capacity of the actuator (3) the above-mentioned actuator manufacturing steps, It is as shown in "Figure 3", and a wrinkled film is formed by etching the silicon wafer on the surface, and then it is shown as "Figure: the sensitive, thin film electrode and junction electrode are joined. 1 " m range, while joining two: extremely However, the bonding stress may destroy the formed wrinkled film, which will have an impact on the yield of the actual production. Because of the purpose and summary of the invention, the object of the present invention is to provide a The manufacturing method of a component with a wrinkled film, such as an actuator or a pressure gauge, is expected to reduce the cost and process time, and also improve the yield and productivity.-'According to the above-mentioned object of the present invention, Miniature element

5. Description of the invention (4) At least: providing a dream substrate and a glass substrate, and a metal thin film is formed on the glass substrate; 'etching' to define a thin film region on the Shixi substrate; forming a protective layer on the thin film region; Define the pattern of the film area, and form a circular wrinkle by isotropic wet etching. Remove the protective layer, and dope an ion into the circular wrinkle to form a wrinkle film. Join the silicon substrate and the glass substrate to make the metal film. It is placed on the film area, corresponding to the wrinkled film; and the back side is carved with a substrate to expose the wrinkled film. Based on the complexity and repeatability of circular pleated films, Hu Jin will develop two series of computer programs to automatically generate circular patterns for use as photomasks for micro-processing. #Electrical components are composed of two electrode plates, which are respectively defined as a movable electrode plate on a silicon wafer and a fixed electrode plate on the glass of 740. Before the moving electrode plate in V f is formed on the thin film area, the Shixi substrate is formed with an insulating layer to protect Shi Ximei, which is not formed in the thin film area, with a non-isotropic engraving method. = Shell shell] 的 As a mask when digging out the groove, 纟 needs to be formed: 刖 二! One side of the Shi Xi substrate formed in the film region is coated with a layer of photoresist for protection on an HF side. Solution_ form a circle with concentric two: layer and then

V. Description of the invention (5) Fabrication method is doped with boron ions to the silicon substrate to complete the formation of the wrinkled thin-film electrode. The part of the electrode is formed on the glass substrate by thermal evaporation method di: The electrode needs to be made before-pre-alignment and alignment 'is based on-light film: the judgment of the process is almost completed, as for the engraved stone Xijing on the back, it can be used as a topped, which is easy to get the last Wrinkled pattern. The enemy's pleated engraving technology develops a round-shaped enemy robe with electrostatic components. At a low cost, it can quickly produce an integrated micro-electrode with a circular system. In addition, a new backside etching method is used to improve the disadvantages of bulk mi croma chining, and the utilization rate of the surface of the positive film. In the process design of the present invention, only two photomasks are needed to complete the fabrication of the electrostatic component. In addition, considering the mechanical strength of the thin film structure, we chose to make 2, Tier 2 ί ί: Wrinkle film for testing 'W Gray film * with film reflection light image to estimate the actuation ability when used as an actuator, the result 2.5. 5〆 = thin film At a voltage input of 15 volts, the center of the actuator thin film can produce a deflection change of about 1em. In order to make the above and other objects, features, and advantages of the present invention clear, a preferred embodiment is described below in detail with reference to the accompanying drawings, as follows. Description of the drawings: Figures 1 to 4 show conventional electrostatic components with a wrinkled film.

C: \ Program Files \ Patent \ P-0223TW. Ptd Section IM9 V. Description of the invention (6) Production flow chart; The drawing edge shows the implementation of the micro device manufacturing process according to the micro device embodiment of the present invention. Figures 14 ~ 16 5 patterns of the three photomasks shown in the examples are shown; and the knowing party: i I: 8: the actuators and exercises formed by the method of the present invention are illustrated. [Description of the embodiment] This embodiment uses, etc. Directions, including # poles, can be developed in "Figure 5 ~] n J. The thin film of the micro cell is first described with reference to the flow of the". ". The substrate formed by the pleated film. Since the silicon substrate is etched by silicon 10 As the wrinkle direction produces different conditions. With the crystal pattern of the Shixi wafer, the rate of ^ 0 σ ^ hetero-etching depends on the direction of crystal crystallization # θ Φ ^ 1, the silicon crystal etching in the specific direction of the plant is the most efficient, one. § The rate of two η nf will be sequentially weakened according to the order of the following dream crystals. (100) > (1 1〇) > (i 1 丄), so in this example: early crystal silicon (100) Silicon substrate 10 (4-inch p-type silicon substrate, 8 — 120 hm — cm, polished on one side, thickness 325 ~ 37 5 # m). After obtaining the silicon substrate 1Q, the steps of preliminary cleaning (Umtial cleaning) must be performed first. The standard rca cleaning procedure is used to remove particles and impurities on the surface of the Shixi wafer. Then, please refer to "Figure 6". An insulating layer 3 2 is formed on the silicon substrate 丄 above, for example, a layer of silicon dioxide (Si〇2) having a thickness of about 6,000 A formed by wet oxidation (wet oxidation).

C: \ ProgramFiles \ Patent \ P-0223TW.ptd on page 9), ί. Its main function is to protect the silicon substrate 10 portion where the wrinkled film is not formed when the wrinkled film area is etched later. Next, referring to "Figure 7", the surface and surface of the insulating layer 3 will be formed as described in "Figure 14 I. ji J, a, ji J, a thin gland cover 1" to define a grooved, Q, 34. The method used is anisotropic etching with a solution of potassium hydroxide (KOH). To etch away the 282 layer 3 2 on the thin film region 34, the silicon substrate 1 It needs to be immersed in the solution of BOE for about 71 ', and then the surface of the silicon substrate 10 is etched at a temperature of about 60 t, &: it is corrected to 30 wt% KOH for about twenty minutes In this way, a money engraving depth of about 6. 1 / im can be engraved. The sensitive folds to be formed will be made in the film region 34 of this groove. Then, refer to "Figure 8" and repeat the above A protective layer 3 β is further formed on the etched part, for example, a silicon dioxide layer having a thickness of about 800 Å is also formed by a wet process. The main function of the protective layer is to provide a smooth etching mask for wrinkles when wrinkles are formed. After drawing the stripes, please refer to "Figure g", and form the desired wrinkled film in the film area 3 as described above. The method used is a completely different isotropic etching method from the conventional j-energy R I E technology. It is also because of the formation of thin wrinkles with wet engraving technology, so it is known that R〗 E requires investment; the price equipment can be eliminated, and the speed of the process does not need to be as much as R 丨 ^ 辄More than hours. The pattern of the photomask 2 required for the wet etching of the wrinkles in this example is shown in FIG. 15 and is a photomask having two concentric circular stripes 4 2. When making round wrinkles, the base ^

10 = the old side (ie, the side without the film area 3 4) needs to be coated with a photoresist (ph0t0resist), and then, under the mask of the photomask 2, remove the film with B0E solution first The silicon dioxide layer 3 6 'on the area 34 is approximately immersed the entire silicon substrate 10 in the b oe solution for about nine minutes], thereby removing the silicon dioxide layer 3' with a thickness of about 8000 A. 6 'and form a plurality of circular recesses 3 6 2 as shown in the figure. Then 'immerse the Shixi substrate 10 in, for example, a solution of HF_HN03_H2〇, and prepare a mixed solution with a volume ratio of about 1: 10: 5, and after about four minutes of operation time, a plurality of grooves of about 10 vm can be generated. 38. A desired circular wrinkle is formed in the film area 34. However, if the pattern of the mask 2 is changed, wrinkles with different patterns can be defined, for example, wrinkles with spiral lines (convoluted). Therefore, the shape of the wrinkle film of the present invention can be made according to the requirements, and the required wrinkle pattern can be produced by providing the photomask 2 ", and Shi Xi is removed to perform an ion dispersion (dif fus ide» Grade DIA. X 〇 中 '将 Boron For example, the parts around 2.5 / z 'Boron silicide slope into' so the substrate 10 wrinkle surface doping process using the shape ion method, using BN-HT 1100, 0 4 ") in N2 ( In silicon, the boron film 4 m (boros i1i-remove this BSG at a temperature of 110 ° C) will be wrinkled after seeing "silicon dioxide 36 in the figure 10". Thin film. In this embodiment, a flattened diffusion device (Boron Nitr Part No. F40040 > Size 4 " 1 0 1) and 02 (2 50 m 1) diffusion process of boron ions are used. The operating strips take about 1 time. 5 hours can produce 0. In addition, cate glass (BSG) will also form during the boron ion diffusion process.

= Using about 40 minutes in the 9A sequence under the condition of 9 〇 0 t, and then soaking for about 50 minutes in the soilization process of the "bron dilution" step, it will help to remove BSG, so it will be shaped ::: Wrinkle film for boron 'However, besides, it is an enemy pleated film, so the beryllium pleated film should be used depending on the application of the phase centroid diffusion diffusion process to form the desired pleated film. The production of the fixed electrode plate will be described with "Fig. 11". AfeU11 "shows that a metal thin film 18 is formed on the glass soil u ', for example, a glass (4 inches in diameter, 0.5 mm in thickness, and a density of 4 inches in diameter by Py rex # 7740 by a thermal evaporation method). 2.23g // cm3, the thermal expansion coefficient is about 5 × 10—7 (0 ~ 30Q ° C)), forming an aluminum film with a thickness of about 0.5. Among them, the photomask 3 shown in FIG. 16 is used to define the pattern of the aluminum film in the 1J1 fixed electrode. A groove 44 formed on the photomask 3 is caused when the miniature component of the present invention is used as an actuator. The actuator is used in a medical micropump to measure, for example, the characteristics of red blood cells in the blood. The red blood cells can be dripped in through the center of the groove 44 and enter the actuator along the channel of the groove 44 for measurement. After the aluminum film 22 is vapor-deposited on the glass substrate 50, it must be placed in a mixed solution of Η3Ρ04: ΗΝ03: CH3C00H: Η20, and a volumetric solubility ratio of about 50: 2: 1 0: 9 to control the temperature at About 60. (: Left and right, soak for about 50 seconds. Finally, the micro-device manufacturing is completed through the process of "Figures 12 and 13". As shown in "Figure 12", the glass substrate 20 and the silicon substrate 10

V. Description of the invention (10) When bonding (anod i c bond i ng), it is necessary to perform pre-position alignment first, for example, it is completed by Kar 1 Suss A1 i gner machine. In addition, for example, a photoresist can be used as a bonding agent during bonding. After three minutes of preliminary positioning (pre-bonding), the bonding is changed to, for example, a Kar 1 Suss SB6 Bonder machine, under operating conditions: temperature 4600 ′, voltage 100 ′, current 2.10] 11 six (1113 fork ·), Under atmospheric pressure, it takes about 50 minutes. When the maximum current drop is one third of the original value, it indicates that the joining process is almost complete. Then, "as shown in Fig. 13", the backside etching of the stone evening substrate 10 is not stopped until the collar film 40 is exposed. It can be seen that the boron ion diffusion performed in "Fig. 10" has two purposes: one is to form a 2.5-thick thin-film electrode, and the other is to be used for back-etching (etch-stopped). If the above-mentioned application of the micro-component formed by the method of the present invention is used as an actuator ', the comparison of "Figures 16 and 17" can be used to explain the actuator formed by the conventional method as "Figure 4", and The method of the present invention forms actuators such as "drawer 3". The number of actuators that can be formed on a substrate of the same load area can be clearly seen. Not like the conventional method to keep-quite large, huge, so 7 = on the substrate surface has increased a lot, of course, the yield will also increase. [Effects of the present invention] The manufacturing process of the present invention only needs to throw a single wafer (1) from the perspective of the broken substrate used, which can save wafer costs. (2) Only three masks can be used in the manufacturing process.

Not only does this reduce by half 'not only the time required for this process is also shorter, the error is. 'The smaller the number of photomasks used, the finished system can also reduce the φ caused by the alignment during the process. ^' The etching solution used in the back surface etching of the present invention is ΚΟΗ ', and the etching of the D surface name or other processes has EPW is used as an etchant because EPW is highly toxic, so it can reduce the risk of the process. (4) This f is not as thin as conventional boards when it joins silicon substrates and glass substrates. (5) In the present invention, after the silicon substrate and the glass substrate are joined, the backside is engraved with a stone substrate, which can protect the structure of the formed wrinkle film, and at the same time, it can block the intrusion of the etching solution during etching. The gap between the two electrode plates. (+6) Since the broken substrate is the way of etching the entire back surface, when the etched barrier layer of the film is etched, the wrinkle pattern will naturally emerge. It is quite easy to grasp. (7) The backside etching method of the present invention is different from the conventional method, which mainly improves the disadvantages of the traditional overall microfabrication and improves the utilization rate of the substrate surface. The conventional backside money engraving method often causes The area between the V-grooves (not shown in Figure 17) cannot be used, thus greatly reducing the utilization rate of the wafer surface. 'By improving this disadvantage,' the process of the present invention can make full use of the surface of the entire substrate to make the component Production has increased significantly.

(8) The present invention uses an isotropic wet etching technique to produce a circular pleated film. 'This isotropic wet etching only takes about four minutes in the process cost' to reach an etching depth of about 10 m, Compared with the traditional RIE

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Non-isotropic etching, the same depth of etching, it must take tens of hours, it is obvious that the speed increase; m is small: to the wet etching only cost tens of yuan of etching solution cost: wrinkled f? Compared with R1E equipment, which requires thousands of dollars in expenses, the cost is also greatly reduced. Therefore, using the isotropic wet etching technology of the present invention saves time compared to high-energy RI E equipment, it can provide a fast and affordable way to make a circular wrinkled film "In summary, although the present invention has been compared with The preferred embodiment is disclosed above, but it is not intended to limit the present invention. 'Any person skilled in the art can make some modifications and retouches without departing from the spirit and scope of the present invention, for example, if the enemy folds the electrode plate's folds The pattern is changed into a convoluted line, similar to a strain gauge (strain guage) wire. The fixed electrode plate on the other side can be converted into a piezoresistive pressure gauge without an aluminum coating. It can measure low pressure, wind pressure or blood pressure. Shewei provides a measure of south sensitivity. Similarly, the actuator can also be reversed as a capacitive accelerometer. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application. 【Illustration of Symbols】 10 12 14

• Broken substrate. · Groove: Wrinkled Wrinkled film Metal film Glass substrate • Aluminum film

V. Description of the invention (13) • Insulation film area • Protective layer • Grooves • Boron film circular stripes • Grooves • Recesses • Photomask 3 2 ··· 3 4 ··· 3 6 · ·· 3 8 ·· 4 0 ··· 4 2 ··· 4 4 ·· 3 6 2 ·· 1 2 3 3 IIB · C: \ PrograniFiles \ Patent \ P-0223TW_ptd page 16

Claims (1)

6. Scope of patent application A method for manufacturing a micro-component with a wrinkled film, including at least the following steps: 3 Provide a silicon substrate and a glass substrate 'the glass substrate is formed with a metal film; ~ on the silicon substrate, etching Define a thin film area; form a protective layer on the thin film area; define the pattern of the thin film area and form it with an isotropic full name—solid ^ 6 4 feathers · A circular wrinkle to remove the protective layer, and Ions are doped into the circular wrinkle to form a wrinkled film; 'to join the silicon substrate and the glass substrate, so that the metal film is placed in the film region, corresponding to the wrinkled film; and A silicon substrate 'to expose the wrinkled film. 2. The method for making a micro-wrinkled thin film as described in item 1 of the scope of the patent application, wherein the metal film is an aluminum film of 0.5em that is obtained by thermal evaporation. 3, as thick as 3. The microfabrication method for wrinkled thin media as described in item 1 of the scope of the patent application, wherein an insulating layer is first formed on the substrate that includes 7 ^ pieces before forming the film area. i 3 In the silicon 4, as described in item 3 of the scope of the patent application, the micro-wrinkled film is made __ The manufacturing method, wherein the insulating layer is made of a wet oxidation method ^ • the thickness of the piece is about 6000A Silicon oxide layer. 'Formed' 5 The method for manufacturing a wrinkled film as described in item 4 of the scope of patent application, wherein before forming the film region, The silicon dioxide layer C: \ Program Files \ Patent \ P-0223TW. Ptd page 17 6. Scope of patent application — — It takes about 7 minutes to remove it with a Beta E solution. 6. The method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of the patent application, wherein the film region is etched with a KOH solution for about 20 minutes using an anisotropic etching method to form a depth of about 20 minutes. A groove for 6/1 Arn. 7. The method for manufacturing a micro-component with a wrinkled film as described in item 6 of the scope of the patent application, wherein the concentration of the KOΙ solution is about 30 wt%, and the operating temperature is about 60. (:. 8. The method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of the patent application, 'wherein the protective layer is formed by a wet oxidation method and has a thickness of about 8000 A. A silicon layer is used as a mask when the recesses are etched. 9. A method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of the patent application, wherein the recesses are not formed before the recesses are formed. One side of the silicon substrate formed in the area is coated with a layer of photoresist protection. 1 ◦ The manufacturing method of a micro-component with a wrinkled film as described in item 1 of the scope of the patent application, wherein the formation of the wrinkle is preceded by a B 〇E solution, the operation time is about 9 minutes to remove the protective layer of about 8 〇 〇 〇A; and then a HF-Η N 0 3-Η 2 0 solution with a volume ratio of 1: 10: 5, The operation time is about 4 minutes 'to form the wrinkles with a depth of about 10 / zm with a button. 11. A method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of patent application', wherein the wrinkles are thin It is formed by doping a deletion ion by a diffusion method. C: \ Program Files \ Patent \ P-〇223TW. Ptd No. 18 Buy /, 'Applicable patent scope is as described in claim 11 of the patent scope, a method for manufacturing a micro-element with a pleated film, wherein the boron ion diffuses The operating conditions of the process are. • Using a flat-type diffusion device, N2 and O2 were formed at a temperature of about 110 ° C for about 1.5 hours to form a thin film of boron of about 2.5 / zm. 'As in the method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of the patent application, it is required to perform a pre-positioning alignment before joining the silicon substrate and the glass substrate. 4. The method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of the patent application, wherein the bonding of the silicon substrate and the glass substrate uses a photoresist as a bonding agent at a temperature of about 460 t: The voltage is about 100 volts. The maximum current is about 2 · 1 m A, which takes about 50 minutes to complete. 5. According to the method for manufacturing a micro-component with a wrinkled film as described in item 14 of the scope of the patent application, it is judged that the joining process is almost completed by reducing the maximum current to one-third of the original time. 6. The method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of the patent application, wherein the silicon wafer is etch-stopped by etching the silicon wafer on the back surface. 7. The method for manufacturing a micro-component with a wrinkled film as described in item 1 of the scope of patent application, wherein the micro-component comprises an actuator and a sensor. 8. A method for manufacturing a micro-component with a wrinkled film 'includes at least the following steps: C: \ ProgramFiles \ Patent \ P-0223TW.ptd Page 19 6. The scope of the patent application provides a silicon substrate and a glass substrate; on the silicon substrate, a thin film area is defined by etching; a protection is formed on the thin film area Layer; defining the pattern of the film region to form a circular wrinkle by isotropic wet etching; removing the protective layer and doping an ion into the circular wrinkle to form a wrinkle film; bonding the silicon substrate and The glass substrate; and the silicon substrate is etched on the back surface to expose the wrinkled film. 19. The method for manufacturing a micro-element with a wrinkled film as described in item 18 of the scope of patent application, wherein the micro-element includes a piezoresistive pressure gauge and a capacitive accelerometer. C: \ Program Files \ Patent \ P-0223TW.ptd page 20