Method for inspecting microwave capability of plate-type PECVD

Abstract

The invention discloses a method for inspecting the microwave capacity of plate type PECVD. The method comprises: S1, designing coating parameters; S2, selecting a to-be-tested quartz tube, only starting a single-end microwave system of the to-be-tested quartz tube, introducing reaction gas, and coating the silicon wafer by adopting coating parameters to obtain a test wafer sample; S3, circularlyoperating the microwave system at each end of each quartz tube in S2 one by one; S4, respectively selecting the same column of test pieces parallel to the microwave conduction direction on each groupof test piece samples as a test column, detecting the film thickness of each test piece in each test column, and if the difference between the maximum value and the minimum value of the film thicknessin the test column is not greater than 20nm, determining that the microwave capability of the test end of the quartz tube to be tested corresponding to the test column is normal; and if not, determining that the microwave capability of the test end of the corresponding quartz tube to be tested is abnormal. According to the method provided by the invention, the quartz tube with abnormal microwaveconduction and the microwave end with abnormal microwave conduction can be accurately locked, and the reasons of non-uniform coating and productivity reduction can be found out.

Description

technical field [0001] The invention relates to the technical field of silicon cell manufacturing, in particular to a method for inspecting the microwave capability of plate-type PECVD. Background technique [0002] The principle of plate PECVD deposition of silicon nitride film is to use microwaves to ionize the gas containing the constituent atoms of the film to form a plasma to react, thereby depositing the desired film on the substrate. Whether the microwave capability is normal largely determines whether the deposition of the silicon nitride film can meet the standard. [0003] Microwave refers to electromagnetic waves with a frequency of 300 MHz to 300 GHz, and the capability of microwave will decrease with the increase of transmission distance. Under normal circumstances, the linear microwave power will gradually decline from the input end along the direction of the quartz tube; but when there is an abnormality in the hardware such as the quartz tube, the decline tre...

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Problems solved by technology

[0005] The above method judges that the specific gas flowmeter of the quartz tube is relatively high or low through the mismatch between the film thickness and the refractive index data of a certain quartz tube, so as to find out that the conversion efficiency of the cells produced by the PECVD device is low However, it cannot solve the problems of uneven coating and chromatic aberration in the production process, because when the above method is used to compare the data of each group of quartz tubes horizontally, there will be no obvious data anomalies, so it is impossible to find It is found out that which quartz tube fails to affect the microwave capability of the entire equipment, and at the same time, it is impossible to accurately identify which end of the quartz tube has weakened microwave capability. At present, there is no corresponding troubleshooting method. Therefore, when the microwave When the conduction is abnormal in the silicon nitride film deposition process, the usual way is to replace all the quartz tubes blindly, which will undoubtedly increase the production cost, and even if the quartz tube is replaced, it often cannot fundamentally solve the problems caused by the abnormal microwave conduction. Therefore, there is an urgent need for a method that can accurately troubleshoot and test microwave capabilities.

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