Method for preparing silicon-on-insulator material using selective corrosion process

Abstract

A method for preparing a silicon-on-insulator material using selective corrosion process comprises the following steps: providing a doped monocrystalline silicon substrate; growing an undoped intrinsic monocrystalline silicon layer on the surface of the monocrystalline silicon substrate; growing a component layer on the surface of the monocrystalline silicon substrate; providing a support substrate; growing an insulating layer; bonding the monocrystalline silicon substrate with the support substrate; selecting the selective corrosion process to remove the doped monocrystalline silicon substrate; removing the intrinsic monocrystalline silicon layer. The invention is characterized by adopting the intrinsic monocrystalline silicon layer as the etch-stop layer and removing the intrinsic monocrystalline silicon layer in post process by methods of overheating oxidation and the like, thus the technical proposal provided by the invention can be used for preparing the silicon-on-insulator substrate with top silicon of arbitrary resistivity.

Description

【Technical field】 [0001] The invention relates to the field of semiconductor devices, in particular to a method for preparing a silicon-on-insulator material by using a selective etching process. 【Background technique】 [0002] Compared with bulk silicon devices, silicon-on-insulator (SOI) devices have the advantages of high speed, low driving voltage, high temperature resistance, low power consumption, and radiation resistance. rapid development. According to the thickness of the top silicon thin layer, SOI materials can be divided into two categories: thin film SOI (the thickness of the top silicon is less than 1 micron) and thick film SOI (the thickness of the top silicon is greater than 1 micron). [0003] At present, the preparation technologies of SOI materials mainly include oxygen injection isolation technology (SIMOX), bonding and backside etching technology (BESOI) and its derived smart stripping technology (Smart-cut), epitaxial layer transfer technology (ELTRAN)...

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Problems solved by technology

In this method, the corrosion selectivity of HNA solution to materials with different resistivity is utilized. However, the doping concentration required for HNA solution to achieve a good corrosion selectivity ratio has obvious differences, which limits the use of this technology in the preparation of low resistivity materials. Application of top layer silicon (resistivity less than 10Ω·cm) SOI substrate

And the epitaxial lightly doped layer is directly on the heavily doped substrate. Due to the self-doping effect, there is a transition zone with a gradual resistivity change between the heavy and lightly doped layers, instead of showing a steep resistivity distribution, and the transition The local resistivity distribution in the region is not uniform, which makes the thickness uniformity of the top silicon layer of the prepared SOI substrate poor.

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