Fluorine-containing residue removing method, etching method and oxide layer cleaning method

Abstract

The invention provides a fluorine-containing residue removing method, an etching method and an oxide layer cleaning method. The fluorine-containing residue removing method comprises the following steps that S1, a wafer obtained after technology processing is conveyed into an annealing cavity; and S2, a blowing gas and an ammonia gas are introduced into the annealing chamber to remove fluorine-containing residues on the wafer. According to the technical scheme of the fluorine-containing residue removing method, the etching method and the oxide layer cleaning method provided in the invention, afluorine content on the wafer after the process can be reduced so that a leakage current of the device is reduced, and performance of the device is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor processing, in particular to a method for removing fluorine-containing residues, an etching method and an oxide layer cleaning method. Background technique [0002] Native oxide cleaning technology for high aspect ratio channels is one of the most challenging steps in 3D NAND (computer flash memory devices). This process requires the complete removal of the natural oxide layer. At the same time, the removal of TEOS (tetraethyl silicate) on the sidewall of the channel needs to be as small as possible, and the residual oxygen and fluorine content at the bottom of the channel after cleaning are as low as possible. Especially for the fluorine content, its level will directly affect the leakage current of the device. This is because the residual fluorine will react with substances in the subsequent deposition process of the Ti film layer to form a titanium fluoride (TiFx) by-product, which will ...

AI Technical Summary

Problems solved by technology

This is because the residual fluorine will react with the substances in the deposition process of the subsequent Ti film layer to form a titanium fluoride (TiFx) by-product, which will further affect the quality of the Ti film layer and eventually increase the leakage current of the device

[0003] After the existing dry etching method completes the etching of the wafer, the fluorine content on the wafer is relatively high. Compared with the wafer without the etching process, the fluorine content on the etched wafer increases by more than 5 times. cause the leakage current of the device to increase

Images