Quartz products and heat treatment apparatus

Abstract

The present invention relates to control of copper contamination to semiconductor substrates upon operation of a heat treatment apparatus which is a semiconductor manufacturing apparatus and which is constructed with quartz products having been contaminated with copper when machined. The quartz product is placed in a heating atmosphere on the stage where it is not still used for a heat treatment for semiconductor substrates. Baking gases including a hydrogen chloride gas and a gas for enhancing activity of the hydrogen chloride gas, for example, an oxygen gas, are then supplied to the quartz product. Consequently, the copper concentration in the region from the surface to the 30 mum depth of the quartz product can be controlled below 20 ppb, preferably below 3 ppb. The baking process may be carried out before or after assembling the quartz product into the heat treatment apparatus.

Description

technical field [0001] The present invention relates to a technique for removing metal contained in a quartz product by baking the quartz product as a component of a heat treatment apparatus for heat-treating a semiconductor substrate. Background technique [0002] As one of the heat treatment equipment used in the semiconductor manufacturing process, there is a vertical heat treatment equipment which is a batch type heat treatment equipment. This vertical heat treatment apparatus includes a heating furnace having a vertical reaction tube opened at the bottom and a heat source provided so as to surround the outside of the reaction tube. A plurality of semiconductor wafers (hereinafter referred to as wafers) are held in a wafer holder called a wafer boat in the shape of a partition, and are carried in from the lower side of the reaction tube, and are subjected to oxidation treatment, diffusion treatment, or formation by CVD in the reaction tube. Membrane treatment etc. [0...

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Problems solved by technology

Therefore, only the number of atoms on the surface of the quartz product is used to evaluate the copper contamination of the quartz product, which cannot effectively prevent the contamination of the wafer.

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