Wafer gettering method

Abstract

The present invention provides a wafer gettering method. The method comprises: performing a first annealing on a to-be-treated wafer, wherein the first annealing is performed under an oxygen atmosphere and a first temperature condition for a first time; depositing a polysilicon layer on a surface of the to-be-treated wafer; performing a second annealing on the to-be-treated wafer, wherein the second annealing is performed under an inert gas atmosphere and a second temperature condition for a second time which is greater than or equal to the first temperature. According to the wafer gettering method, the polysilicon layer can effectively adsorb oxygen atoms in the vacancies, thereby removing wafer defects; the two annealing processes can promote atom rearrangement and further eliminate defects in the to-be-treated wafer; the second annealing can uniformly heat the to-be-treated wafer in a short time by microwave annealing, thereby improving the activity of atomic motion and further improving the annealing efficiency; and the two annealings are performed at lower temperatures, which can avoid wafer warpage caused by high annealing temperature and improve wafer quality.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a wafer gettering method. Background technique [0002] Wafers, especially silicon wafers, are the basis for the manufacture of semiconductor integrated circuits. A silicon wafer is usually pulled from a polysilicon melt by a Czochral-ski method (English: Czochral-ski method, CZ for short) to prepare single crystal silicon, and then the single crystal silicon is cut into silicon wafers. [0003] However, intrinsic defects including self-interstitial atoms and vacancies usually exist in silicon wafers currently fabricated using the CZ method. According to Voronkov's crystal growth theory, the above-mentioned intrinsic defects are affected by the crystal pulling rate and the axial temperature gradient of the solid-liquid interface. Since the distribution of the axial temperature gradient of the CZ growth furnace with the same structure is basically fixed, the crystal pullin...

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Problems solved by technology

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a wafer gettering method for solving the problem of poor wafer quality in the prior art

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