A method for removing difficult-to-volatile substances on wafers

Abstract

The invention provides a method for removing non-volatile substances on a wafer, which is applied in the tungsten back-etching process of the deep trench isolation process technology, and the non-volatile substances are easy to be generated in the deep trench isolation process technology, and the non-volatile substances adhere to on the wafer; including the following steps: step S1, placing the wafer in a reaction chamber; step S2, heating the wafer, and feeding a first reaction gas and a second reaction gas into the reaction chamber ; Step S3, controlling the heating temperature of the wafer to remove metal impurities attached to the wafer; Step S4, maintaining the flow rate of the second reaction gas introduced, so that the second reaction gas reacts with the hard-to-volatile substance to form a volatile sexual substance. The beneficial effect of the technical solution is that it overcomes the defect in the prior art that the wafer yield rate is low due to the existence of non-volatile substances and metal impurities attached to the wafer.

Description

technical field [0001] The invention relates to the technical field of semiconductor preparation, in particular to a method for removing non-volatile substances on a wafer. Background technique [0002] In the existing deep trench isolation manufacturing process, when the semiconductor structure is formed on the wafer, the metal layer and the nitride layer on the Temos oxide layer in the semiconductor structure can be cleaned by W-CMP (tungsten chemical mechanical polishing). Remove, or use W etch back (tungsten etching process) to remove the metal layer and nitride layer on the Temos oxide layer in the semiconductor structure, and W etch back (tungsten etching process) in the etching process , the non-volatile substances formed when depositing the metal oxide layer on the semiconductor structure are not easy to remove, and the metal that falls on the semiconductor during the deposition of the metal layer is attached to the crystal grains of the semiconductor substrate, such...

AI Technical Summary

Problems solved by technology

[0002] In the existing deep trench isolation manufacturing process, when the semiconductor structure is formed on the wafer, the metal layer and the nitride layer on the Temos oxide layer in the semiconductor structure can be cleaned by W-CMP (tungsten chemical mechanical polishing). Remove, or use W etch back (tungsten etching process) to remove the metal layer and nitride layer on the Temos oxide layer in the semiconductor structure, and W etch back (tungsten etching process) in the etching process , the non-volatile substances formed when depositing the metal oxide layer on the semiconductor structure are not easy to remove, and the metal that falls on the semiconductor during the deposition of the metal layer adheres to the crystal grains of the semiconductor substrate, such as these non-volatile substances and If the metal attached to the die is not removed in time, it will affect the final yield of the semiconductor structure

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