Surface residue removing device and method for wafer wet etching

Abstract

The invention discloses a surface residue removing device and method for wafer wet etching, the removing device comprises a wafer base plate and a driving gear located at the center of the wafer base plate, and the center of the wafer base plate is provided with a cavity for accommodating the driving gear; a plurality of cavities communicated with the cavity are uniformly formed in the wafer chassis along the circumferential direction of the cavity where the driving gear is located, and driven gears meshed with the driving gear and used for vertically placing a plurality of wafers are arranged in the cavities. When the wafer is removed, the wafers are sequentially arranged on the driven gear, and then the wafer base plate is placed in the etching liquid to etch the wafers; and after etching is started, the driving gear is rotated every 10-20 min so as to drive the wafer on the driven gear to rotate, and the wafer is rotated for 2-3 circles every time until etching is finished. According to the surface residue removing device for wafer wet etching, the inclined insertion sheet groove in the vertical direction is formed in the driven gear, so that a plurality of wafers can be vertically placed, and the contact area is small; and on the basis of the placement mode, the driven gear is driven to rotate in combination with the transmission of the driving gear, so that residues generated on the surface of the wafer can be removed in time, and normal wet etching of the wafer is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer wet etching, and in particular relates to a surface residue removal device and a removal method for wafer wet etching. Background Art

[0002] Wet etching is a micromachining method that removes materials by placing crystal materials in an etching solution. Selective processing of crystal material etching structures can be achieved by designing mask structures on the wafer, selecting the type and concentration of etching solutions, and controlling process parameters such as etching temperature and time. Wet etching has processing advantages such as low cost and high quality, and is widely used in various fields of micromechanical systems, including electronics, transportation, aerospace, communications, and medical care.

[0003] During the wet etching process, the wafer and the etching solution react chemically to form products. If the products are not removed in time, they are likely to adhere to the surface of the wafer and act as a micro-mask, affecting the normal wet etching. Therefore, it is very important to remove the residues on the surface of the wafer during the wet etching process.

[0004] At present, existing wet etching experiments rarely take this into consideration, because most of the products produced are soluble in the etching solution and can be dissolved after a period of time; but if the products produced by the crystal material and the etching solution are insoluble, it will hinder the normal progress of wet etching.

[0005] Based on this, a surface residue removal device and method for wafer wet etching are developed, which can effectively remove the products generated on the wafer surface in a timely manner during the etching process. Summary of the invention

[0006] Purpose of the invention: The technical problem to be solved by the present invention is to provide a surface residue removal device and method for wafer wet etching, so as to effectively remove the products generated on the wafer surface in a timely manner during the etching process.

[0007] Technical solution: The present invention is a device for removing surface residues from wet etching of wafers, which includes a wafer chassis and a driving gear located at the center of the wafer chassis, a cavity for accommodating the driving gear is opened in the center of the wafer chassis, a plurality of cavities connected to the cavity are evenly distributed along the circumference of the cavity where the driving gear is located on the wafer chassis, and a driven gear meshing with the driving gear and used for vertically placing a plurality of wafers is arranged in the cavity.

[0008] Furthermore, the driven gear of the removal device is provided with two support blocks with inclined surfaces which are arranged opposite to each other, and the inclined surfaces of the support blocks are provided with a plurality of slots for placing wafers.

[0009] Furthermore, a base for mounting the driven gear is provided on the cavity where the driven gear of the removal device is located, and a portion at the bottom of the wafer chassis cavity corresponding to the base is hollowed out.

[0010] Furthermore, a base for mounting a driving gear is provided at the cavity of the wafer chassis of the removal device.

[0011] Furthermore, a rotating rod is connected to the upper end of the driving gear of the removal device, so that the driving gear is driven to rotate by rotating the rotating rod, thereby driving a plurality of driven gears to rotate.

[0012] The present invention provides a method for removing residues from the surface of a wafer based on the above device, comprising the following steps:

[0013] (1) After arranging the wafers on the driven gears in sequence, the wafer chassis is placed in the etching liquid to etch the wafers;

[0014] (2) After etching starts, the driving gear is rotated every 10-20 minutes to drive the wafer on the driven gear to rotate, 2-3 turns each time, until etching is completed.

[0015] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the surface residue removal device for wet etching of wafers can place several wafers vertically with a small contact area by setting a vertically inclined insert slot on the driven gear; and based on this placement method, combined with the active gear transmission to drive the driven gear to rotate, the residue generated on the wafer surface can be removed in time to ensure normal wet etching of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the removal device of the present invention (the wafer is not placed, and a driven gear is hidden);

[0017] Figure 2 It is a schematic diagram of the structure of the removal device of the present invention (placing wafer). DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0019] like Figure 1 and Figure 2 As shown, the device of the present invention can not only be used for placing wafers during the wet etching process of wafers, but can also effectively remove the products generated on the surface of the wafer in a timely manner during the entire wet etching process.

[0020] Specifically, the removal device includes a wafer chassis 1 for placing wafers, a cavity is opened in the center of the wafer chassis 1, and a plurality of cavities connected to the cavity are evenly distributed along the circumference of the cavity on the wafer chassis 1. A driving gear 2 is arranged in the cavity, and a plurality of driven gears 3 are arranged in the plurality of cavities, and the plurality of driven gears 3 are meshed with the driving gear 2, and then the rotation of the driving gear 2 drives the linkage of the plurality of driven gears 3.

[0021] The driving gear 2 is provided with a rotating rod 7 connected thereto. The driven gear 3 is provided with two supporting blocks 4 arranged opposite to each other at its center, and each supporting block 4 is provided with an inclined surface, and a plurality of slots 5 are provided on the corresponding inclined surface, so that the wafer can be placed vertically through the inclined slots, thereby reducing the contact area between the wafer and the supporting block 5.

[0022] The driving gear 2 and the driven gear 3 are connected through the cavity of the wafer chassis 1 and the base 6 in the cavity. The base 6 corresponding to the driven gear 3 and the wafer chassis 1 form a hollow setting, that is, the wafer chassis 1 located at the cavity is provided with an opening, and the opening is connected with the base 6 of the driven gear 3 to form a hollow shape, so that the generated products on the surface of the driven gear 3 can be effectively removed during the rotation process without silting.

[0023] The present invention provides a method for removing residues from the surface of a wafer based on the above device, comprising the following steps:

[0024] (1) After the wafers are arranged in sequence and placed on the driven gear, the wafer chassis 1 is placed in the etching liquid to etch the wafers;

[0025] (2) After etching starts, the driving gear 2 is rotated every 10-20 minutes to drive the wafer on the driven gear 3 to rotate, and each rotation is 2-3 circles until the etching is completed. The rotation time of each circle can be adaptively adjusted according to the actual etching solution, preferably 8-10 seconds per circle.

[0026] The following takes the etching of sapphire (Al2O3) using a mixed solution of concentrated sulfuric acid (H2SO4) and concentrated phosphoric acid (H3PO4) as an example, and describes the specific removal method in combination with the above-mentioned device.

[0027] Among them, the chemical reaction of sapphire with concentrated sulfuric acid is: Al2O3+3H2SO4+3H2O=Al2(SO4)3·3H2O, and the product aluminum sulfate trihydrate Al2(SO4)3·3H2O is insoluble in concentrated sulfuric acid etching solution; the chemical reaction of sapphire with concentrated phosphoric acid is: Al2O3+6H3PO4=2Al(H2PO4)3+3H2O and Al2O3+Al(H2PO4)3=3AlPO4+3H2O, and the final product aluminum phosphate AlPO4 is soluble in concentrated phosphoric acid etching solution.

[0028] Example 1: Using a mixed solution with a concentration of H2SO4:H3PO4=1:5 to etch sapphire

[0029] The method for removing residues from the surface of a wafer based on the above device comprises the following steps:

[0030] (1) After arranging the wafers on the driven gear in sequence, the wafer base is placed in the mixed solution, and the wafers are etched at an etching temperature of 230° C.;

[0031] (2) After the etching starts, the driving gear is rotated every 20 minutes to drive the wafer on the driven gear to rotate, 2 turns each time, and the rotation time of each turn is 8 seconds per turn until the etching is completed, that is, the whole etching process is 4 hours.

[0032] Example 2: Using a mixed solution with a concentration of H2SO4:H3PO4=5:1 to etch sapphire

[0033] The method for removing residues from the surface of a wafer based on the above device comprises the following steps:

[0034] (1) After arranging the wafers on the driven gear in sequence, the wafer base is placed in the mixed solution, and the wafers are etched at an etching temperature of 230° C.;

[0035] (2) After the etching starts, the driving gear is rotated every 10 minutes to drive the wafer on the driven gear to rotate, 3 turns each time, and the rotation time of each turn is 10 seconds per turn until the etching is completed, that is, the whole etching process takes 4 hours.

Claims

1. A surface residue removal device for wafer wet etching, characterized in that: The removal device comprises a wafer chassis (1) and a driving gear (2) located at the center of the wafer chassis (1); a cavity for accommodating the driving gear (2) is provided at the center of the wafer chassis (1); a plurality of cavities connected to the cavity are evenly distributed along the circumference of the cavity where the driving gear is located on the wafer chassis (1); a driven gear (3) meshing with the driving gear (2) and used for vertically placing a plurality of wafers is provided in the cavity.

2. The surface residue removal device for wafer wet etching according to claim 1, characterized in that: The driven gear (3) is provided with two support blocks (4) which are arranged opposite to each other and have inclined surfaces, and the inclined surfaces of the support blocks (4) are provided with a plurality of slots (5) for placing wafers.

3. The surface residue removal device for wafer wet etching according to claim 2, characterized in that: The cavity in which the driven gear (3) is located is provided with a base (6) for mounting the driven gear (3), and a portion at the bottom of the cavity of the wafer chassis (1) corresponding to the base (6) is arranged in a hollow shape.

4. The surface residue removal device for wafer wet etching according to claim 1, characterized in that: A base (6) for mounting the driving gear (2) is provided in the cavity of the wafer chassis (1).

5. The surface residue removal device for wafer wet etching according to claim 1, characterized in that: The upper end of the driving gear (2) is connected to a rotating rod (7) so that the driving gear (2) can be driven to rotate by rotating the rotating rod (7), thereby driving a plurality of driven gears (3) to rotate.

6. A method for removing residues from the surface of a wafer based on the device of claim 1, characterized in that: The steps include: (1) After arranging the wafers in sequence and placing them on the driven gear (3), the wafer base (1) is placed in an etching solution to etch the wafers; (2) After etching begins, the driving gear (2) is rotated every 10-20 minutes to drive the wafer on the driven gear (3) to rotate 2-3 circles each time until etching is completed.

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