Method for removing substance difficult to volatilize from wafer

Abstract

The invention provides a method for removing a substance difficult to volatilize from a wafer, applied to a tungsten etching back process of a deep trench isolation processing process; in the deep trench isolation processing process, the substance difficult to volatilize is generated easily, and the substance difficult to volatilize is attached to the wafer; the method comprises the following steps of S1, putting the wafer into a reaction cavity; S2, heating the wafer, and pumping first reaction gas and second reaction gas to the reaction cavity; S3, controlling the heating temperature on thewafer to remove metal impurities attached on the wafer; and S4, maintaining the flow of the pumped second reaction gas to enable the second reaction gas to be reacted with the substance difficult to volatilize so as to form a volatile substance. The technical scheme has the beneficial effects that the shortcoming of relatively low wafer yield caused by the fact that the substance difficult to volatilize and metal impurities are attached on the wafer in the prior art can be overcome.

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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