Method for reinforcing wafer during uniform coating process

Abstract

The application discloses a reinforcing method of wafer in a uniform glue process, step 1, two experimental slides with different sizes are prepared and attached, then a blue film is attached to the whole surface to fix the two experimental slides; step 2, the blue film is opened on the small experimental slide in step 1, and the blue film is removed; step 3, the small experimental slide is replaced by a wafer, and the blue film is reattached; step 4, the blue film at the edge of the wafer is rolled to be free of bubbles; step 5, after the large experimental slide in step 4 is uniformly glued by using a uniform glue machine, the large experimental slide is removed, the blue film is torn off from the edge, the wafer is removed and is baked on a hot plate, and then the wafer uniform glue process is completed, and the application provides a technical means for how to uniformly glue the wafer in a photoetching process, and solves the problem that the wafer is easily broken in the existing uniform glue process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor lithography, and relates to a reinforcing method for wafer in the process of spin coating. BACKGROUND

[0002] With the development of semiconductor chip manufacturing technology, the thickness of chips is continuously reduced, which has caused many technical problems, one of which is that the wafer is at a great risk of breaking in the process of subsequent manufacturing, thereby greatly reducing the yield of chip manufacturing or even making the process impossible.

[0003] The lithography process is a common technical method in the process of manufacturing semiconductor chips, mainly including spin coating, lithography, development and other processes. In the process of spin coating, the wafer is adsorbed on the stage by vacuum suction and rotated at high speed to form a film. However, many product designs require lithography patterns on the back of the wafer after thinning, and in fact, the wafer after thinning cannot complete the spin coating process due to the limited capacity of the equipment, because the wafer after thinning cannot withstand the vacuum suction of the stage, which often causes breakage. The present application provides a new reinforcing method, which realizes the spin coating process of the wafer after thinning by using the carrier as a support. SUMMARY

[0004] The purpose of the present application is to provide a reinforcing method for wafer in the process of spin coating, which solves the problem of easy breakage of the wafer in the process of spin coating in the prior art.

[0005] The technical solution adopted by the present application is a reinforcing method for wafer in the process of spin coating, which is implemented according to the following steps:

[0006] Step 1: Prepare two experimental carriers of different sizes, adhere them together, and then fix the two experimental carriers by adhering a blue film to the entire surface.

[0007] Step 2: Open a hole in the blue film on the small experimental carrier in step 1, and remove the blue film.

[0008] Step 3: Replace the small experimental carrier with a wafer after thinning and re-adhere the blue film.

[0009] Step 4: Roll the blue film on the edge of the wafer after thinning until there is no air bubble.

[0010] Step 5: After spin coating the large experimental carrier in step 4 using a spin coater, remove the large experimental carrier, tear off the blue film from the edge, remove the wafer after thinning, and perform hot plate baking, thereby completing the spin coating process of the wafer after thinning.

[0011] The present application has the following characteristics:

[0012] The size of the small experimental carrier in the two experimental carriers of different sizes in step 1 is the same as the size of the wafer, and the small experimental carrier is placed in the center of the large experimental carrier;

[0013] In step 2, the shape of the opening is determined according to the shape of the wafer, and the size of the opening is within 2mm-3mm of the actual wafer edge;

[0014] In step 3, the replacement process is specifically: after the blue film after the opening is torn off, the small experimental carrier is completely removed, the position of the small experimental carrier is marked, the small experimental carrier is taken off, the wafer is placed on the marked position with the uniform glue surface facing up and coinciding with it, and the blue film is reattached;

[0015] In step 3, the thickness of the wafer is not more than 200μm and the size is not more than Φ4".

[0016] The beneficial effects of the present application are

[0017] The wafer reinforcing method in the wafer uniform glue process of the present application is to support the wafer with external force to ensure that it does not break, and to cover the area outside the wafer edge with a blue film to prevent the area from being covered with photoresist in the uniform glue process, thereby ensuring the feasibility of smoothly taking the wafer off the carrier after uniform glue. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a wafer process schematic diagram of step 2 in the wafer reinforcing method in the wafer uniform glue process of the present application;

[0019] Figure 2 is a wafer process schematic diagram in example 2 in the wafer reinforcing method in the wafer uniform glue process of the present application. DETAILED DESCRIPTION

[0020] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0021] The present application provides a wafer reinforcing method in the wafer uniform glue process, which is specifically implemented according to the following steps:

[0022] Step 1, first find a wafer with the same size as the wafer, and an experimental carrier larger than the wafer, place the small experimental carrier in the center of the large carrier, and fix the two experimental carriers together with a blue film;

[0023] Step 2, open the blue film on the small experimental carrier in step 1 with an art knife, and remove it, the shape of the opening is determined according to the shape of the wafer, and the size of the opening is within 2mm-3mm of the actual wafer edge, as shown in Figure 1 ;

[0024] Step 3, tear the blue film after the opening to the small experimental slide is completely exposed, stop tearing the blue film, mark the position of the small experimental slide with a fine marker, take down the small experimental slide, place the regular or irregular (size not greater than Φ4") wafer with a thickness of the wafer slice below 200 μm face up on the marked position and coincide with it, and reattach the blue film;

[0025] Step 4, use a flat or round cotton swab to gently roll the blue film at the edge of the wafer slice to be free of bubbles;

[0026] Step 5, after the large experimental slide in step 4 is spin-coated, take down the slide, gently tear the blue film from the edge, take down the wafer slice for hot plate baking, and then the wafer slice spin-coating process is completed.

[0027] Example 1 (one piece of thin slice to 100 μm thickness Φ2" Inp wafer spin-coating process)

[0028] Step 1, find a Φ4" silicon wafer and a Φ2" silicon wafer, place the small silicon wafer in the center of the large silicon wafer, and fix the two silicon wafers together with a blue film on the whole surface;

[0029] Step 2, use a knife to open the blue film on the Φ2" silicon wafer in step 1, and remove it, the opening shape is a circular flat edge, and the opening size is within 2 mm from the edge;

[0030] Step 3, tear the blue film after the opening to the Φ2" silicon wafer is completely exposed, stop tearing the blue film, mark the position of the Φ2" silicon wafer with a fine marker, take down the Φ2" silicon wafer, place the thin slice to 100 μm thickness Φ2" Inp wafer spin-coating surface face up on the marked position and coincide with it, and reattach the blue film;

[0031] Step 4, use a flat cotton swab to gently roll the blue film at the edge of the wafer slice to be free of bubbles;

[0032] Step 5, after the large experimental slide in step 4 is spin-coated, take down the slide, gently tear the blue film from the edge, take down the wafer slice for hot plate baking, and then the wafer slice spin-coating process is completed.

[0033] Example 2 (one piece of thin slice to 200 μm thickness Φ3" GaAs special-shaped wafer spin-coating process)

[0034] Step 1, find a Φ4" silicon wafer and a Φ3" silicon wafer, place the small silicon wafer in the center of the large silicon wafer, and fix the two silicon wafers together with a blue film on the whole surface;

[0035] Step 2, use a knife to open the blue film on the Φ3" silicon wafer in step 1, and remove it, the opening shape is a circular flat edge, and the opening size is within 2 mm from the edge;

[0036] Step 3, tear the blue film after opening the hole to Φ3" silicon wafer completely exposed stop tearing blue film, mark the position of Φ3" silicon wafer with a fine marker, take down Φ3" silicon wafer, place the Φ3" Inp profile wafer with a thickness of 100 μm to the uniform glue surface upward on the marked position and coincide with it, and reattach the blue film;

[0037] Step 4, use a flat cotton swab to gently roll the blue film at the edge of the wafer to be thin to no bubble as shown: Figure 2

[0038] Step 5, after using the glue uniform machine to glue the Φ4" silicon wafer in step 4, take down the wafer, gently tear off the blue film from the edge, take down the wafer to be thin for hot plate baking, and then complete the wafer to be thin glue process.​

Claims

1. A method for reinforcing thin wafers during the homogenization process, characterized in that, The method is implemented according to the following steps: Step 1, prepare two experimental slides with different sizes, adhere them together, and then fix the two experimental slides by adhering blue film on the whole surface; Step 2, punch holes in the blue film on the small experimental slide in step 1, and remove the blue film; Step 3, replace the small experimental slide with a wafer, and re-adhere the blue film; Step 4, roll the blue film at the edge of the wafer until there is no bubble; Step 5, after the large experimental slide in step 4 is uniformly coated by using a coating machine, remove the large experimental slide, tear off the blue film from the edge, remove the wafer, and then perform hot plate baking, thereby completing the wafer coating process; The replacement process in step 3 is specifically as follows: stop tearing the blue film after the small experimental slide can be completely removed, mark the position of the small experimental slide, remove the small experimental slide, place the wafer with the uniform coating surface upward at the marked position and coincide with the small experimental slide, and then re-adhere the blue film.

2. The method of claim 1, wherein the method is performed in a spin coating process. In step 1, the size of the small experimental slide is the same as that of the wafer, and the small experimental slide is placed in the center of the large experimental slide.

3. The method of claim 1, wherein the method is performed in a spin coating process. In step 2, the shape of the punched hole is determined according to the shape of the wafer, and the size of the punched hole is within 2mm-3mm from the edge of the actual wafer.

4. The method of claim 1, wherein the method is performed during a process of spin coating. In step 3, the thickness of the wafer is not greater than 200μm, and the size is not greater than Φ4". In step 3, the thickness of the wafer is not greater than 200μm, and the size is not greater than Φ4".

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