A lt and ln incoming bare chip coating process

Abstract

The application discloses a LT and LN raw wafer coating process. The application generates chemical reaction through NMP soaking, changes the properties of the surface of the LT and LN, improves the wafer cleanliness, reduces the water drop angle, improves the adhesion of the glue during the spin coating, and then through stripping and cleaning, keeps the surface clean and dry, which can solve the phenomenon of incomplete coating of the LT and LN raw wafer during the spin coating, and fully improve the product quality and yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor gluing process, in particular to a LT and LN incoming wafer coating process. BACKGROUND

[0002] The gluing method in the yellow light process is roughly divided into two categories of spin coating and spraying, (generally adopted substrate is silicon base and glass), wherein the principle of spin coating gluing is to rely on centrifugal force to coat the glue from the center to the periphery, so that the whole wafer is fully coated, and the good thickness uniformity of the whole wafer can be achieved. However, in actual product research and development, customers have requirements on the material quality of the final product, such as LT & LN (lithium carbonate & lithium niobate), and through comparison of various measurement data, the solid content of the two materials is different from that of the silicon base, and the surface smoothness, water drop angle and roughness are quite different, which will cause the phenomenon of incomplete coating in the edge zone during the coating process, such as Figure 1 As shown in the figure, the surface of the wafer is not fully coated with glue, which will affect the quality and yield of the product. SUMMARY

[0003] To solve the above technical problems, the present application designs a LT and LN incoming wafer coating process. The surface pretreatment is added before gluing to optimize the gluing effect and solve the surface coating abnormality problem, improve the surface properties, improve the surface cleanliness, and optimize and improve the phenomenon of incomplete coating of the LT and LN incoming wafer surface.

[0004] The present application adopts the following technical scheme:

[0005] A LT and LN incoming wafer coating process, the process steps are:

[0006] S1, the LT and LN incoming wafer is put into the immersion tank card slot of the glue removing machine and soaked with NMP (N-methyl pyrrolidone) for a period of time;

[0007] S2, after the soaking is completed, the LT and LN incoming wafer is transported to the stripping cavity, and the surface of the LT and LN incoming wafer is stripped with NMP in the stripping cavity to remove the surface residues;

[0008] S3, the LT and LN incoming wafer completed step S2 is conveyed to the cleaning cavity, and IPA (isopropyl alcohol) and N2 are used to flush and blow through the nozzle in the cleaning cavity, and after the flushing is completed, DIW (pure water) is used to flush through the nozzle to remove the NMP residue on the surface;

[0009] S4, the LT and LN incoming wafer completed step S3 is spun dry, and the LT and LN incoming wafer is spin coated through the spin coating process to complete the whole LT and LN incoming wafer coating process.

[0010] As preferred, in step S1, the LT and LN incoming wafer is put into the degumming machine for NMP immersion for 3 minutes at 80℃.

[0011] As preferred, in step S1, the immersion is accompanied by up and down swinging of the card slot in the immersion slot to increase the contact rate of the substrate and the liquid.

[0012] As preferred, in step S2, the stripping process in the stripping cavity is carried out by clamping the LT and LN incoming wafer by a mechanical arm and rotating at a fixed speed, while a high-pressure nozzle swings back and forth to wash the surface of the wafer with NMP at high pressure for 120 seconds.

[0013] As preferred, the liquid pressure of the high-pressure nozzle is controlled at 0.3-0.4 MPa.

[0014] As preferred, in step S3, the IPA and N2 flushing and blowing conditions are as follows: IPA flushing pressure 0.05-0.1 MPa, N2 blowing pressure 0.2-0.3 MPa, and flushing time 90 seconds.

[0015] As preferred, in step S3, the DIW flushing conditions are as follows: DIW flushing pressure 0.3-0.3 MPa, and flushing time 90 seconds.

[0016] As preferred, in step S4, the LT and LN incoming wafer is clamped by a mechanical arm and spun at 3000 rpm for 90 seconds.

[0017] The present application has the following advantages: the present application generates a chemical reaction by NMP immersion, changes the properties of the LT and LN surface, improves the cleanliness of the wafer, reduces the water droplet angle, improves the adhesion of the glue during spin coating, and keeps the surface clean and dry through stripping and cleaning, which can solve the problem of incomplete coating of the LT and LN incoming wafer during spin coating, and fully improve the product quality and yield. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the LT and LN incoming wafer after coating by the existing coating process;

[0019] Figure 2 is a schematic diagram of the LT and LN incoming wafer after coating by the coating process of the present application; DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be further described in detail below with specific examples and in conjunction with the drawings:

[0021] Example: a LT and LN incoming wafer coating process, the process steps of which are as follows:

[0022] S1, put the LT and LN incoming wafer into the soaking slot of the degumming machine, soak for 3 min at 80℃ with NMP; while soaking, the slot swings up and down in the soaking tank to increase the contact rate of the substrate and the liquid;

[0023] S2, after soaking, the LT and LN incoming wafer is transported to the stripping cavity, and the surface of the LT and LN incoming wafer is stripped with NMP in the stripping cavity; while stripping, the LT and LN incoming wafer is clamped by a mechanical arm and rotated at a fixed speed, and a high-pressure nozzle swings back and forth to wash the surface of the LT and LN incoming wafer with NMP at high pressure for 120 s to remove the surface residues, and the liquid pressure of the high-pressure nozzle is controlled at 0.3-0.4 MPa;

[0024] S3, the LT and LN incoming wafer after step S2 is transported to the cleaning cavity, and IPA (isopropyl alcohol) and N2 are used to flush and blow through the nozzle, and the flushing and blowing conditions of IPA and N2 are as follows: the IPA flushing pressure is 0.05-0.1 MPa, the N2 blowing pressure is 0.2-0.3 MPa, and the flushing time is 90 s; after flushing, DIW (pure water) is used to flush through the nozzle, and the flushing conditions of DIW are as follows: the DIW flushing pressure is 0.3-0.3 MPa, and the flushing time is 90 s; the surface NMP residues are completely removed;

[0025] S4, the LT and LN incoming wafer after step S3 is clamped by a mechanical arm and spun at 3000 rpm for 90 s, and the LT and LN incoming wafer is spin-coated by a spin coating process to complete the entire LT and LN incoming wafer coating process.

[0026] The product after the LT and LN incoming wafer is spin-coated by the process of the present application is shown in FIG. 1, and it can be seen that there is no phenomenon of incomplete coating during spin coating, which fully improves the product quality and yield. Figure 2

[0027] The measurement value of the water drop angle of the LT and LN incoming wafer before and after NMP soaking is detected, and it can be seen that the water drop angle of the LT and LN incoming wafer before soaking is large, and the water drop angle of the LT and LN incoming wafer after soaking is small; reducing the water drop angle improves the adhesion of the glue during spin coating, which solves the phenomenon of incomplete coating of the LT and LN incoming wafer during spin coating, and fully improves the product quality and yield.

[0028] The above-described embodiments are only a preferred scheme of the present application, and do not limit the present application in any form, and other variants and modifications are possible without exceeding the technical scheme recited in the claims.​

Claims

1. A coating process for LT and LN raw wafers, characterized in that, The process steps are as follows: S1. Place the LT and LN raw sheets into the soaking tank slot of the degumming machine and soak them in NMP for a period of time. S2. After soaking, the LT and LN raw wafers are transported to the peeling chamber. In the peeling chamber, NMP is used to peel the surface of the LT and LN raw wafers to remove surface residues. S3. The LT and LN raw wafers that have completed step S2 are transferred to the cleaning chamber. In the cleaning chamber, IPA and N2 are used to rinse and blow through the nozzle. After rinsing, DIW is used to rinse through the nozzle to remove the NMP residue on the surface. S4. After completing step S3, spin dry the LT and LN raw wafers and spin coat them to complete the entire LT and LN raw wafer coating process. In step S1, the LT and LN raw wafers are placed in the desizing machine and soaked in NMP for 3 minutes at a temperature of 80°C. In step S2, the peeling process in the peeling chamber is achieved by a robotic arm holding the LT and LN raw sheets and rotating them at a fixed speed, while a high-pressure nozzle swings back and forth to use NMP to perform high-pressure washing and peeling on their surfaces for 120 seconds. The liquid pressure of the high-pressure nozzle is controlled at 0.3-0.4 MPa; In step S3, the conditions for rinsing and blowing IPA and N2 are as follows: IPA rinsing pressure 0.05-0.1 MPa, N2 blowing pressure 0.2-0.3 MPa, and rinsing time 90 s. In step S3, the rinsing conditions for DIW are: DIW rinsing pressure 0.3-0.3MPa, rinsing time 90s.

2. The coating process for LT and LN raw wafers according to claim 1, characterized in that, In step S1, while soaking, the card slot swings up and down in the soaking tank to increase the contact rate between the substrate and the liquid.

3. The LT and LN raw material coating process according to claim 1, characterized in that, In step S4, the spin-drying process of the LT and LN raw wafers involves holding the LT and LN raw wafers with a robotic arm and spin-drying them at 3000 rpm for 90 seconds.

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