Method for preparing SOI by reducing injection damage

Abstract

The invention provides a method for preparing SOI by reducing injection damage. The method comprises the following steps: selecting three original silicon wafer which are a first silicon wafer, a second silicon wafer and a third silicon wafer respectively; mechanically thinning the first silicon wafer and oxidizing the second silicon wafer and the third silicon wafer; performing primary bonding onthe oxidized second silicon wafer and the thinned first silicon wafer so as to obtain a primary bonding wafer; performing ion injection on the primary bonding wafer; stripping the primary bonding wafer after ion injection; performing secondary bonding on the stripped primary bonding wafer and the oxidized third silicon wafer so as to obtain a secondary bonding wafer; splitting the secondary bonding wafer to obtain a silicon structure on the insulating layer; and annealing and chemically polishing the silicon structure on the insulating layer so as to obtain the high quality SOI. The method for preparing the SOI by reducing injection damage can remove injection damage and ion residue, effectively reduce SOI defects and significantly improve the surface state of the silicon wafer.

Description

technical field [0001] The invention generally relates to the technical field of silicon wafers, and more specifically relates to a method for preparing SOI with reduced implant damage. Background technique [0002] Silicon-On-Insulator (SOI) is a new type of silicon-based semiconductor material with a unique three-layer structure of "Si / insulator / Si". SiO 2 ) realizes the full dielectric isolation of the device and the substrate. [0003] At present, the thermal microwave separation technology (TM-SOI, also known as "thermal microwave splitting method") to prepare thin film SOI is to oxidize and implant the original silicon wafer, bond it with another original silicon wafer or silicon oxide wafer, and then pass thermal Microwave technology separates the silicon wafer from the implanted layer to obtain a silicon structure on the insulating layer. As an example, among two silicon wafers, an oxide film is formed on at least one silicon wafer, and hydrogen ions or rare gas i...

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Problems solved by technology

[0004] However, in actual production, ion implantation will cause ion damage and ion residue on the surface of the silicon wafer, making the particles and roughness of the prepared SOI surface poor, and the yield of SOI cannot be guaranteed, which needs to be improved urgently.

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