Method for producing bonding wafer

Abstract

A method for producing a bonded wafer by the ion implantation delamination method includes at least a step of bonding a bond wafer having a micro bubble layer formed by gaseous ion implantation and a base wafer serving as a support substrate and a step of delaminating the bond wafer at the micro bubble layer as a border to form a thin film on the base wafer. After the delamination of the bond wafer, the bonded wafer is subjected to a heat treatment in an atmosphere of an inert gas, hydrogen or a mixed gas thereof, then the bonded wafer is subjected to thermal oxidation to form a thermal oxide film on the surface of the thin film, and then the thermal oxide film is removed to reduce thickness of the thin film.

Description

technical field [0001] The present invention relates to a method of manufacturing a bonded wafer using an ion implantation debonding method, and particularly relates to a method of manufacturing an SOI wafer by bonding a silicon wafer implanted with hydrogen ions or the like as a support substrate to another wafer and then debonding it. Background technique [0002] Recently, as a method for manufacturing SOI (silicon on insulator) wafers, a method of manufacturing SOI wafers by peeling off ion-implanted wafers after bonding (ion implantation stripping method: also called Smart Cut method (registered trademark) ) technology) began to attract attention again. This ion implantation stripping method is a technique as described below (refer to Japanese Patent Application Laid-Open No. 5-211128): an oxide film is formed on at least one of the two silicon wafers, and an oxide film is formed on the other silicon wafer (bonded wafer). After injecting gas ions such as hydrogen ions ...

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Problems solved by technology

[0012] As described above, the technology described in Japanese Patent Application Laid-Open No. 2000-124092 has the advantage of maintaining the SOI layer while maintaining the damaged layer and surface roughness remaining on the surface of the SOI layer in the ion implantation stripping method. The uniformity of film thickness was eliminated, but when the inventors of the present invention conducted further tests on this technology, it was found that there were the following disadvantages, and it is known that it is not sufficient as a mass production technology.

[0013] 1) The sacrificial oxidation in the above technology uses ion implantation to directly oxidize the peeled surface, so there will be cases where oxidation induced stacking faults (OSF: Oxidation induced Stacking Fault) will occur due to oxidation. removed during heat treatment

[0014] 2) In the heat treatment in a reducing gas environment, the surface roughness that is fully removed is mainly short-period components (for example, the period is below 1 μm), and the removal of long-period components of the surface roughness (for example, about a period of 1 to 10 μm) is sometimes insufficient.

[0015] 3) As a reducing gas environment, if high-temperature heat treatment is performed in a gas environment containing a large amount of hydrogen, hydrogen may sometimes act on the bonding interface, and the interface erosion will increase, which will become the cause of dust generation in the device process

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