Novel SiC anti-warping film deposition process method

Abstract

The invention relates to the field of crystal processing, in particular to a novel SiC anti-warping thin film deposition process method, which comprises the following steps of: at the beginning stage of the process, firstly adsorbing a wafer, and checking the vacuum degree to ensure that the wafer is smoothly adsorbed without leakage; in the technological process, the heating table conducts adsorption in the whole process, and the film growth uniformity is guaranteed; after the process is finished, a stress release link is added, and the wafer stress is released by increasing the temperature of a heating table, so that the wafer is prevented from warping again after being cooled. According to the anti-warping thin film deposition process method, by modifying a corresponding structure, adding a bottom adsorption leveling link and applying a reverse acting force to the substrate in the SiC substrate process, it is guaranteed that the deposited thin film uniformly grows on the surface of the substrate, by adding a stress release link, the wafer after the process is finished is prevented from warping again, and the yield of the wafer is improved. And the process yield of the wafer is greatly improved.

Description

Technical Field

[0001] The invention relates to the field of crystal processing, and in particular to a novel SiC anti-warping film deposition process method. Background Art

[0002] The third-generation semiconductor SiC has excellent characteristics such as a larger bandgap, high breakdown electric field, high thermal conductivity, high electron saturation rate, and strong radiation resistance. Devices with SiC as the substrate are smaller, more efficient, and more energy-efficient, which is more in line with the future needs of the global technology industry for the consensus on the goal of "carbon peak and carbon neutrality". The main processes for the preparation of SiC materials and chips are single crystal growth, substrate cutting and polishing, epitaxial growth, mask deposition, patterning, etching, injection, heat treatment, metal interconnection and other process flows involving dozens of key semiconductor equipment.

[0003] Plasma-enhanced chemical vapor deposition (PECVD) technology is a method that uses external energy to assist the decomposition of reaction precursors to generate plasma, thereby realizing the preparation of SIC thin films. SiO2 films deposited by PECVD have the advantages of low reaction temperature, uniform film formation, good step coverage and process repeatability. However, for thinner SiC substrates, high-temperature warping is prone to occur during process reactions. This is because the expansion coefficient of SiC substrates is several times that of SiO2. During the process at 400°C, the expansion rate of SiC is significantly faster than that of silicon dioxide, which causes the SiC substrate to be pulled into a concave shape by silicon dioxide, and the uniformity of film deposition will be significantly affected. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a novel SiC anti-warping film deposition process method to solve the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the technical solutions adopted are as follows:

[0006] A novel SiC anti-warping film deposition process method comprises the following steps:

[0007] S1: Check and call the production process program, and the equipment self-check has no alarm and meets the production conditions;

[0008] S2: The vacuum breaking process of the upper and lower chambers is completed, and the wafers are loaded into the upper and lower chambers and the doors are closed;

[0009] S3: After the wafer is loaded, the equipment starts to run automatically, the upper and lower chambers start to be vacuumed, and the wafer basket rotates to the loading position;

[0010] S4: Scan the number of wafers loaded in the wafer basket and manually confirm that the loading is OK;

[0011] S5: Flat edge cavity preparation, the robot takes the material to the flat edge cavity, and the flat edge cavity completes the wafer flat edge alignment;

[0012] S6: The process chamber performs self-inspection, and the process starts when the temperature and vacuum degree are qualified;

[0013] S7: The robot takes and places the wafer into the process chamber, and the wafer placement is completed;

[0014] S8: The heating table starts vacuum adsorption and adsorbs the wafer on the heating table;

[0015] S9: Check the vacuum degree to ensure that the surface of the heating table is flat and leak-free;

[0016] S10: Start the production process and call the process formula;

[0017] S11: The process operation is completed and the wafer is kept in the adsorption state;

[0018] S12: Increase the temperature of the heating stage to release the wafer stress;

[0019] S13: Stress release is completed, and the vacuum degree of the process chamber and the transmission chamber is adjusted;

[0020] S14: The robot grabs the wafer to the cooling chamber for cooling and waits for cooling to be completed;

[0021] S15: After the wafer is cooled, the robot grabs the wafer and puts it into the unloading chamber;

[0022] S16: The unloading chamber detects whether the wafer basket is full, and the wafer is manually taken out to enter the next cycle.

[0023] Preferably, in step S8, the suction cup has an adsorption vacuum degree of 0.07-0.15Pa.

[0024] Preferably, in step S12, the temperature of the heating stage is increased to 390-420°C.

[0025] Preferably, in step S13, the vacuum of the process chamber and the transmission chamber are matched, the vacuum degree of the process chamber is reduced from 0.3-0.6 Pa to 5 Pa, and the vacuum degree of the transmission chamber is 5 Pa.

[0026] The beneficial effects of the present invention are:

[0027] At the beginning of the process, the wafer will be adsorbed first and the vacuum degree will be checked to ensure that the wafer is adsorbed flatly without leakage; during the process, the heating table will be adsorbed throughout the process to ensure the uniformity of film growth; after the process is completed, a stress release link is added to release the stress of the wafer by increasing the temperature of the heating table to prevent the wafer from warping again after cooling.

[0028] The anti-warping film deposition process method of the present invention modifies the corresponding structure and adds a bottom adsorption and leveling link in the SiC substrate process to apply a reverse force to the substrate, thereby ensuring that the deposited film grows evenly on the surface of the substrate, and by adding a stress release link, prevents the wafer from warping again after the process is completed, thereby greatly improving the process yield of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 It is a structural schematic diagram of wafer warping in the present invention. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0033] refer to Figure 1 A novel SiC anti-warping film deposition process method comprises the following steps:

[0034] S1: Check and call the production process program, and the equipment self-check has no alarm and meets the production conditions;

[0035] S2: The vacuum breaking process of the upper and lower chambers is completed, and the wafers are loaded into the upper and lower chambers and the doors are closed;

[0036] S3: After the wafer is loaded, the equipment starts to run automatically, the upper and lower chambers start to be vacuumed, and the wafer basket rotates to the loading position;

[0037] S4: Scan the number of wafers loaded in the wafer basket and manually confirm that the loading is OK;

[0038] S5: Flat edge cavity preparation, the robot takes the material to the flat edge cavity, and the flat edge cavity completes the wafer flat edge alignment;

[0039] S6: The process chamber performs self-inspection, and the process starts when the temperature and vacuum degree are qualified;

[0040] S7: The robot takes and places the wafer into the process chamber, and the wafer placement is completed;

[0041] S8: The heating table starts vacuum adsorption, the suction cup vacuum degree reaches 0.07-0.15Pa, and the wafer is adsorbed on the heating table;

[0042] S9: Check the vacuum degree to ensure that the surface of the heating table is flat and leak-free;

[0043] S10: Start the production process and call the process formula;

[0044] S11: The process operation is completed and the wafer is kept in the adsorption state;

[0045] S12: Raise the temperature of the heating stage to 390-420°C to release the wafer stress;

[0046] S13: After stress release is completed, adjust the vacuum degree of the process chamber and the transmission chamber; make the vacuum degree of the process chamber and the transmission chamber match, reduce the vacuum degree of the process chamber from 0.3-0.6Pa to 5Pa, and the vacuum degree of the transmission chamber is 5Pa;

[0047] S14: The robot grabs the wafer to the cooling chamber for cooling and waits for cooling to be completed;

[0048] S15: After the wafer is cooled, the robot grabs the wafer and puts it into the unloading chamber;

[0049] S16: The unloading chamber detects whether the wafer basket is full, and the wafer is manually taken out to enter the next cycle.

[0050] Embodiment 1

[0051] In step S8, the suction cup vacuum is adjusted to 0.07Pa, and the wafer is adsorbed on the heating table; in step S12, the temperature of the heating table is increased to 390°C to release the stress of the wafer; in step S13, the vacuum of the process chamber and the transmission chamber are matched, the vacuum of the process chamber is reduced from 0.3Pa to 5Pa, and the vacuum of the transmission chamber is 5Pa.

[0052] Embodiment 2

[0053] In step S8, the suction cup vacuum is adjusted to 0.15Pa, and the wafer is adsorbed on the heating table; in step S12, the temperature of the heating table is increased to 420°C to release the stress of the wafer; in step S13, the vacuum of the process chamber and the transmission chamber are matched, the vacuum of the process chamber is reduced from 0.6Pa to 5Pa, and the vacuum of the transmission chamber is 5Pa.

[0054] Embodiment 3

[0055] In step S8, the suction cup vacuum is adjusted to 0.11Pa, and the wafer is adsorbed on the heating table; in step S12, the temperature of the heating table is increased to 400°C to release the stress of the wafer; in step S13, the vacuum of the process chamber and the transmission chamber are matched, the vacuum of the process chamber is reduced from 0.4Pa to 5Pa, and the vacuum of the transmission chamber is 5Pa.

[0056] At the beginning of the process, the wafer will be adsorbed first and the vacuum degree will be checked to ensure that the wafer is adsorbed flatly without leakage; during the process, the heating table will be adsorbed throughout the process to ensure the uniformity of film growth; after the process is completed, a stress release link is added to release the stress of the wafer by increasing the temperature of the heating table to prevent the wafer from warping again after cooling.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A novel SiC anti-warping film deposition process, characterized in that: The following steps are involved: S1: Check and call the production process program, and the equipment self-check has no alarm and meets the production conditions; S2: The vacuum breaking process of the upper and lower chambers is completed, and the wafers are loaded into the upper and lower chambers and the doors are closed; S3: After the wafer is loaded, the equipment starts to run automatically, the upper and lower chambers start to be vacuumed, and the wafer basket rotates to the loading position; S4: Scan the number of wafers loaded in the wafer basket and manually confirm that the loading is OK; S5: Flat edge cavity preparation, the robot takes the material to the flat edge cavity, and the flat edge cavity completes the wafer flat edge alignment; S6: The process chamber performs self-inspection, and the process starts when the temperature and vacuum degree are qualified; S7: The robot takes and places the wafer into the process chamber, and the wafer placement is completed; S8: The heating table starts vacuum adsorption and adsorbs the wafer on the heating table; S9: Check the vacuum degree to ensure that the surface of the heating table is flat and leak-free; S10: Start the production process and call the process formula; S11: The process operation is completed and the wafer is kept in the adsorption state; S12: Increase the temperature of the heating stage to release the wafer stress; S13: Stress release is completed, and the vacuum degree of the process chamber and the transmission chamber is adjusted; S14: The robot grabs the wafer to the cooling chamber for cooling and waits for cooling to be completed; S15: After the wafer is cooled, the robot grabs the wafer and puts it into the unloading chamber; S16: The unloading chamber detects whether the wafer basket is full, and the wafer is manually taken out to enter the next cycle.

2. A novel SiC anti-warping film deposition process according to claim 1, characterized in that: In step S8, the suction cup has a vacuum degree of 0.07-0.15Pa.

3. A novel SiC anti-warping film deposition process according to claim 2, characterized in that: In step S12, the temperature of the heating stage is increased to 390-420°C.

4. A novel SiC anti-warping film deposition process according to claim 3, characterized in that: In step S13, the vacuum of the process chamber and the transmission chamber are matched, the vacuum degree of the process chamber is reduced from 0.3-0.6Pa to 5Pa, and the vacuum degree of the transmission chamber is 5Pa.

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