TW200423248A - Method for aligning etched wafer - Google Patents

Abstract

A method for aligning an etched wafer comprises the following steps: providing a silicon wafer; axially defining a plurality of rows of rectangular external frames using the center of the wafer as a center, in which each row of rectangular frames has a plurality of rectangular frames, the center of each row of rectangular frames is located on an axis passing through the center of the wafer, the sides of two adjacent rectangular frames in each row are parallel or perpendicular to each other, and the sides of a rectangular frame in each row are parallel or perpendicular to the axis; performing a pre-etching on said plurality of rectangular frames to etch out V-shaped grooves; using a rectangular frame free of lateral etching as a rectangular frame with correct lattice orientation; and adjusting the orientation of the wafer so that correct lines formed by alignment of the center axis of the rectangular frames forms into a new horizontal base line, in which the horizontal base line is used as a lattice orientation to perform etching of the remaining portion of the wafer.

Description

200423248 (ii) Description of the invention, the invention relates to a crystal plane alignment method, especially a crystal plane alignment method suitable for inspecting and correcting the crystal lattice direction of the wafer. 5 10 15-First, the substrate used by the general optical fiber array module is a base with a v-shaped groove. The method for making the substrate is a silicon wafer coated with silicon nitride. And dry type engraving 'Transfer the square structure with V-shaped groove pattern to the Shixi wafer with nitride stone Xi, and then pass the residue of the potassium hydroxide chemical solution, because of the lattice surface of Shi Xijing (100) (110) (111) and Nitrile Xixi have different rates of rottenness, that is, the square structure transferred by dry touch engraving on Z Shixi wafer is engraved into a so-called Shixi wafer. The optical fiber soil seat with the v-shaped groove is as shown in FIG. 5A, and FIG. 58 is an enlarged view of the second domain in FIG. 5A. However, the chemical relationship is anisotropic corruption, and the remaining precision and quality of the groove structure are determined by the calibration axis accuracy of the Huangguang process mask reference = Shixi wafer lattice plane ⑽). Therefore, check the wafer in advance The axis of the grid (rigid) and the step of precisely aligning it with the light army are the key to the silicon wafer V-groove process. Taking M ^ Sun and Moon people ashamed because of this, the essence of this positive invention #s to think about a few questions, "Shixi wafer chemical etched crystal facet alignment method", ,,,,, Finally, this invention that benefits the world is completed. 、 Contents of the invention 20 A 厶 J 厶 厶 〇 i + t

The alignment method, value, and green are used to etch the lattice surface of a silicon wafer. B. Examine the correct crystal H in the wafer crystal. TA Is the direction of the day-to-day margin correct? Direction. 5 Another object of the present invention is to check whether another type of silicon wafer is chemically etched on the lattice plane alignment of 楹 徂 2 ^ and determine whether it is effective and quickly check the crystal lattice direction of the wafer and determine the correct The lattice direction is corrected. The column i = to achieve the above-mentioned purpose. The present invention is related to-a method for aligning chemical surnames of Shixi wafers. The method (2) (3) of the present invention includes the following ", a silicon wafer; Circles such as 1A, 2A, and the rectangular frame shown in the circle are defined on the circle. The rectangular frames of the plural columns are all parallel to the horizontal reference line or inclined by 01 degrees, 0 · 2 degrees, etc. (from + 2 15, ^ degrees), and after etching, observe whether there is a side name phenomenon in the moments of each plural sequence. If there is no side description phenomenon, it means the center line of the bottom of the V-shaped groove in the rectangular frame of the column. It passes through the central axis of the lattice plane (⑽), which is also parallel to the two sides between the angle of the rectangular frame and the horizontal reference line tilted +2 to _2 degrees. The standard of the photomask is calibrated according to the central axis, and then the chemistry is performed. Etching can ensure the accuracy and quality of the lattice surface of the V-shaped groove (111). The fourth method of calibrating the lattice surface, as shown in Figure 4A, includes the following steps: Provide a Shi Xi wafer; use this wafer The center of the circle is the center point, and a circular frame of a plurality of columns is defined in each axial direction of 0.1 degrees; each column has a plurality of Shape the outer frame, and then pre-etch the plurality of circular outer frames to form a rectangular etching pattern; take the rectangle with no differential row phenomenon as the rectangle with the correct crystal orientation; 20 200423248 and adjust the wafer direction to make the correct rectangle The straight line formed by the central axis is a new horizontal reference line, and the standard of the photomask is calibrated with this horizontal reference line, and then the wafer chemistry is performed, and the v-groove can be accurately carved, and the crystal can be ensured. Accuracy and quality of the grid (111). 5 Because the present invention does improve the efficacy, it applies for an invention patent according to law. 4. Embodiments The present invention provides a method for aligning the crystal plane of a silicon wafer by chemical etching. The main principle is Use the geometrical figures arranged horizontally or axially to determine the axis of the correct lattice direction by etching the V-groove side etch or the phenomenon of differential rows after the pre-etching of the geometrical figure, and then use that direction The axis is used as a new reference line, and after the wafer direction is adjusted, the chemical etching step is continued to obtain a high-quality and high-precision v-groove structure. The present invention provides four types of judgments. Method U of etching the lattice plane axis direction. One is to define the pre-etched area as a rectangle, and arrange the rectangular frame along the horizontal axis. J, as shown in FIG. The fixed angle is arranged from +2 to -2 degrees, with an interval of 0 "degrees. After the V-shaped groove is etched in the area defined by the rectangular frame, observe the etching of the V-shaped groove. If the etching is as shown in Fig. 1C, 2 occurs. The lattice direction of the axis area of the column is incorrect. If the money is engraved: the situation is as the first = no, no side etch occurs, indicating that the lattice direction of the axis area of the column is correct, the lattice direction of the column formed by this rectangle is the lattice The direction of the lattice of the surface (110) can be used as a new reference line to adjust the direction of the silicon wafer to perform the chemical etching of the silicon wafer V-groove. 200423248 The other 10 rules are shown in Figures 2-8 to 20 and 3A to 3D. The basin judges the lattice: the correct method is the same as the first method, which is judged by the V-groove phenomenon, but the difference is that The plural columns are arranged axially rather than horizontally. Therefore, the center of the rectangular box or the single rectangular box can be directly used as the new horizontal reference line. To adjust the direction of the Shixi wafer, the S # method is to define the pre-etched area as the With the circular outer frame arranged axially, the circular outer frame is chemically engraved as shown in FIG. 4A. The difference from the previous method is that the method does not use V-grooves as observation objects, but observes the rectangular pattern arrangement after etching a rectangular pattern. Because the rectangular outer frame is drawn along the lattice direction, if the axial direction of the circular outer frame is exactly the lattice direction, the rectangular outer frame will be arranged parallel to the axial direction, forming Figure 4b shows the arrangement. If the lattice direction is not on the axis where the circular outer frame is located, as shown in FIG. 4C, there will be a step of 15 y between the rectangular outer frames, forming a differential row phenomenon. After that, the straight line formed by the rectangles with no difference in rows is used as a new reference line 'for mask alignment and chemical etching. The method of defining the rectangular and circular frames described above is to first form an S "N4 layer on the wafer; and to etch the Si # 4 layer by lithography and dry etching (RIE) and chemical wet etching 20 times. Perform rectangular or circular etching patterns. There is no limitation on the method of forming the Si3N4 layer, preferably PECVD. There is no limitation on the method of pre-etching, and it is preferable to perform wet etching with an etching solution containing 20% to 40% potassium hydroxide by weight ' Until the V-shaped groove or rectangular frame is etched. 200423248 In order to allow the investigation committee M to better understand the technical content of the present invention, the specific embodiment # 1 is described as follows. 5 15 = Refer to the W, the 3D_ This is a schematic diagram of the method for aligning silver engraved crystal planes using a long rectangular frame for pre-engraving. First, an engraved area is defined on a Shi Xi wafer, centered on the center of the Shi Xi wafer. A plurality of diameters are defined in the axial direction. Please refer to the subordinate figure. In this implementation, the diameter of the horizontal line that is horizontal at the cutting surface of the #round bottom (11G) is defined as (〇, 〇) diameter, and this (〇, 〇) ) Diameter is counterclockwise = Wei Yue-2 bribe and the _ diameter ^ is (-2, +2) diameter. This implementation That is, the area with the (+ 2, _2) diameter sweeping diameter is selected as the pre-zone, and the selected diameters are all different from each other. ❹ By: lithography W wafer M layer is set. Rectangular H makes the mother-rectangular The areas are arranged axially at a certain diameter. The photolithography step is to apply a layer of photoresist on the _4 layer, and f2 to output the rectangular outer frame of the pre-sculpted area, and then expose and The development process is defined, and 4 layers of sand are etched with RIE square wire to form an overhang area; take 4 and then wash away the photoresist, leaving only the Si3N4 pre-etched area. After the definition of the pre-etched area is completed, it will be included 20% to 40% deuterium hydrogen = Dagger potassium's #etching solution is wet-typed, after about 2 to

V-grooves are carved. After being more stupid than 1st phase, I observed each pre-cut area with a microscope, and the observation results found that the v-grooves on the diameter between (-〇 · 2, +0.2) and ㈠4, + 〇.4) were engraved. Plot 20 200423248 ^ The 'shown' is the correct orientation of the lattice; the rest of the area is as shown in 3C, such as the second: side remnant phenomenon occurs, that is, the lattice direction is incorrect. Therefore, it is necessary to adjust the direction of the circle in the photomask alignment operation so that the diameter between Continued) and ㈠.4, + 〇.4) becomes a new horizontal reference line, following the v-shaped groove ⑽i Add W and chemist / work, you can complete the above-mentioned observation and alignment methods. The discernible accuracy is about 01 to 0.2. Compared with conventional techniques, this accuracy is greatly improved.

10 Method for pre-etching ridges using frames… Please refer to FIGS. 4A to 4D, which are schematic diagrams of the method for aligning the lattice plane of the preliminarily-shaped circular frame j 仃 according to the present invention. As in the embodiment i, a pre-etched area is defined on the silicon wafer. The center of the silicon wafer is used as the center point, and a plurality of diameters with a circular frame are defined axially. Definitions As described in Example 1, the selected diameters are all 01 degrees apart. Fo

Then, a photolithography method is used to define a circular frame etching pattern on the sisN4 layer on the silicon wafer, so that each circular area is axially aligned in a certain straight line. The photolithography step is also described in Example 1. '' After the definition of the pre-etched area is completed, it contains 20 to 40% hydroxide

The 20-pot etching solution is wet-etched, and a rectangular frame can be etched after about 1 to 2 hours. After X, each pre-etched area was observed with a microscope. The observation results showed that the rectangular arrangement of the diameters between (-0.3, +0.3) and (-0.6, +0.6) was in a straight line as shown in Figure 4B. Arrangement, no difference row phenomenon occurs, for the lattice is 11 = 2 direction: = domain, as shown in Figure 4C, there is a difference row phenomenon, adjust it in the industry. Γ: Can be seen in Figure 4D in the photomask Align the bamboo chemical level reference line, and continue the exposure, development, dry and ..., large engraving work, you can complete the V-groove machining. The discernible accuracy of the know-how it observation method is about 0.2 to 0.4 degrees, which is the same as that of the practice skills. This accuracy is greatly improved. = As can be seen from the above, the present invention provides a novel ㈣ crystal lattice face 10, /, which can not only observe whether the engraving situation of Shi Xi wafers is correct, but also find out the correct lattice direction to make the wafers chemically During the engraving operation, the problem of poor side quality caused by incorrect alignment of the lattice plane can be reduced, and the mother wafer can be correctly engraved, which greatly reduces the production cost. In addition, the observation and alignment methods provided by Benming are simpler and more convenient than conventional techniques, and have 15 effective amplitudes to improve the observation accuracy, which is a major breakthrough in this field of technology. —As shown on Red, the present invention, regardless of its purpose, means, and efficacy, shows its characteristics that are different from the conventional technology, and it is one of the "methods for aligning the lattice plane of chemical engraving on Shixi wafers". Breakthrough, please call for granting a quasi-patent early. However, it should be noted that the above-mentioned embodiments are merely examples for convenience of explanation. The scope of rights claimed by the present invention shall be based on the scope of the patent application, rather than being limited to the above-mentioned embodiments. V. Brief Description of the Drawings 12 200423248 Figures 1A to ID show the invention using a rectangular frame to align the crystal plane on the face of the method. Figure 1A is the overall schematic diagram; the first is the lattice direction with no side money. The intention of the trench. Figure 1 (: The figure is a schematic diagram of the correct etching of the trench in the lattice direction I where the side name occurs. Figure 1D is the second intention of etching the lattice direction. Figures 2A to 2D are chemical faces of the rectangular frame of the present invention. Figure 2A is a schematic diagram of the overall method; Figure 2B is a schematic diagram of the V-shaped groove when the lattice direction is aligned correctly; The second figure is a diagram showing the alignment of the lattice direction in the remainder of the picture.

Standard diagram. T 15 20

Figure A is a schematic diagram of the body; the first rotten lattice direction is aligned with the correct description of the V 1 slot; the third port, the 3C figure is the incorrect lattice alignment direction, and the V-shaped groove of the German phenomenon Schematic diagram of trench alignment. The 3D picture shows the etching of the crystal Γ-Α sound to the material frame of the present invention. The lattice faces are accurate TI: row TI diagram. The overall schematic diagram; Figure 4β is aligned with the lattice direction. Figure 4C is the lattice alignment direction is incorrect, there is a difference; the side is the _lattice. Figure 5A is the conventional lattice plane. Magnified view of the domain. H5B figure is the virtual circle of figure 5A. 13 200423248 VI. Explanation of figure number None 0

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Claims (1)

Scope of patent application: · 'Even wafer chemical silver engraved crystal face alignment method? Including the following (a) Provide a silicon wafer; > (b) With the center of the silicon wafer as the center point, A rectangular outer frame of a plurality of columns; to a horizontal or axial definition of a plurality of rectangular boxes or single-long and rectangular boxes in which each column has a plurality of rectangles or a single column, each time it passes the center of the wafer The axis or pass = middle = Yu Yitong line; Ding% ° The axis of the center of the wafer (C) of the wafer is engraved on the rectangular boxes, and the grooves are shaped; the long rectangular box is being transformed The G axis or the rectangle has 15-middle " correct lattice; t = the freshness at the bottom of the groove inside the box :): first adjust the orientation of the silicon wafer during the mask alignment operation so that it is correct = :: this : The flat datum line is the correct lattice direction, and the broken wafer is etched dry or wet. 20-step preparation · ★ The lattice plane alignment method described in item 1 of the patent scope, when the center of this or s material is set to a number of rectangular boxes or single-long rectangular boxes--°: Xi Ri The axis of the circle center uses the center axis as the correct lattice direction of the wafer. 15 200423248 2. The method for aligning crystal planes as described in item 1 of the scope of patent application, wherein the steps of defining a rectangular or long box of z V step (a) are as follows: (1) Prior to the silicon wafer Forming a layer of S "N4; and (H) lithographically patterning the residual pattern. The ShN4 layer defines a rectangular or elongated shape ^ t the lattice plane alignment method described in item 1 of the scope of patent application, Among them: the step of engraving the village is to perform wet etching with a solution containing dove to peach heavy hydroxide to etch out a V-shaped groove. Ίο 15 20 5 · The crystal as described in item 3 of the scope of patent application The grid alignment method, in which the formation method of the ^ SljN4 layer is formed by PECVD. The method of grid alignment of the Japanese Yen chemical plutonium includes the following circle (a) to provide a Shixie column circle: ^ 才 [, where The parent column has a plurality of circular outer frames; the engraved pattern (:) is chemically etched on the plurality of circular outer frames to form a rectangle. ⑷ Take a rectangle with no difference image as the correct lattice #direction and the moment at: f During the alignment operation, adjust the direction of the Shi Xi wafer so that it is positive, and the straight line formed by the == is the new level The reference line, the exposure, and the direction; to perform the remainder of the shredded wafer: ... shell ~ dry or wet etching operation. This step =) ^ Special: Wai / 6 lattice grid alignment method described in, The axial direction of 1 () refers to the diameter direction of the Shixi wafer. 16 200423248 —8 · The method of aligning the lattice plane as described in item 6 of the patent scope, among which there are several The center of the circular frame is located on a sleeve line passing through the center of the silicon wafer. 9. The lattice plane alignment method described in item 6 of the scope of patent application, wherein the step of (a) defines the circular frame As follows: 彳 ', ⑴ form a si3N4 layer on the silicon wafer; and (η) define a circular etching pattern on the SisN4 layer by photolithography. 10. As described in item 6 of the scope of patent application Lattice plane alignment method, wherein the pre-etching step of step (c) is performed by wet etching with a contact solution containing 20% to 40% by weight of 10 potassium hydroxide, until the rectangular pattern is etched. 11 · The method for aligning an etched lattice plane as described in item 8 of the scope of patent application, wherein the method for forming the S "N4 layer is PECVD. Way to form. 17