Method and device for detecting purity of trichlorosilane

Abstract

The invention provides a method and a device for detecting purity of trichlorosilane. The method comprises the following steps: (1) pressing TCS in a TCS storage tank into a buffer tank through pressure difference, and pressing the TCS into a reaction tank from the buffer tank; (2) reacting the TCS with pre-added water in the reaction tank to generate silicide and hydrochloric acid, and reacting metal impurities contained in the TCS with chloride ions to generate metal chloride; and (3) extracting products in the reaction tank, analyzing the products with a device inductive coupled plasma mass spectrometry to obtain the amounts of chlorine and metal, converting the chlorine into the amount of the TCS, and calculating the purity of the trichlorosilane. The method and the device have the advantages that: quick detection is realized; the device has simple sampling; the existing metal detecting equipment such as ICP-MS (inductive coupled plasma mass spectrometry) in a semiconductor factory is utilized; economic loss caused by pollution of the poor-quality trichlorosilane to the equipment is avoided; and the utilization rate of the equipment is greatly improved.

Description

technical field [0001] The invention relates to a simple method and device for detecting the purity of trichlorosilane, which can be used in semiconductor factories to monitor the quality of incoming materials. Background technique [0002] In the silicon wafer epitaxy process, silicon compounds such as trichlorosilane (TCS) and dichlorosilane (DCS) need to be used as silicon sources, and silicon atoms decomposed during high-temperature reactions form a silicon layer on the silicon wafer. The metal impurities of these DCS and TCS not only affect the quality of epitaxial wafers, but also cause contamination of equipment. The metal in the silicon source enters the silicon epitaxial layer during epitaxial growth. Some metal impurities gather in the epitaxial layer to form defect cores that affect the quality of the epitaxial layer, and some metal atoms form impurity levels in the epitaxial layer to affect device performance. TCS (or DCS) with metal impurities not only leads to...

AI Technical Summary

Problems solved by technology

However, in a general semiconductor factory, purchasing special equipment separately will inevitably increase the cost. The general epitaxial factory controls the quality of TCS (or DCS) by strengthening the audit of suppliers and growing intrinsic epitaxial layers.

[0004] However, the growth of intrinsic epitaxy is generally not used for incoming material inspection. It is only implemented after the quality of the epitaxial wafers has problems and various possible influencing factors are excluded. contamination

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