Preparation method of SOI (Silicon-On-Insulator) substrate material

Abstract

The invention discloses a preparation method of an SOI (Silicon-On-Insulator) substrate material and belongs to the SOI wafer preparation technical field. According to the method, the substrate material is an SOI substrate wafer with a doped polycrystalline silicon layer or doped amorphous silicon layer. The preparation method of the invention includes the following steps that: (1) a high-resistance silicon wafer is provided; (2) a silicon oxide layer is prepared on the surface of the high-resistance silicon wafer, the thickness of the silicon oxide layer is 150 to 600 angstroms; and (3) a doped polycrystalline silicon layer or doped amorphous silicon layer is prepared on the surface of the silicon oxide layer, so that the SOI substrate sheet with the doped polycrystalline silicon layer orthe doped amorphous silicon layer is obtained. According to the SOI substrate wafer, the doped polycrystalline silicon layer or doped amorphous silicon layer is applied; the doped polycrystalline silicon layer or doped amorphous silicon layer can be effectively connected with silicon oxide; and therefore, parasitic conductance on the surface of the silicon substrate can be effectively suppressed,capacitance variation can be limited, the power of generated harmonics can be reduced, and thus, the loss of the resistivity of the high-resistance SOI substrate can be minimized.

Description

technical field [0001] The invention relates to the technical field of SOI sheet preparation, in particular to a method for preparing an SOI silicon substrate material, and the prepared silicon substrate is mainly used in radio frequency equipment. Background technique [0002] The materials currently used for RF front-end modules are as follows: [0003] 1. SOQ (silicon on silicon on quartz), SOS (silicon on sapphire sapphire): SOQ is the same as traditional SOI, it produces lower leakage current, due to its lower parasitic capacitance, high frequency Circuit performance has been improved. The advantage of SOS is its excellent electrical insulation, which can effectively prevent the radiation caused by stray currents from spreading to nearby components. Substrates such as SOQ and SOS can achieve excellent RF performance, but there are very few such structures, so they are very expensive. [0004] 2. High-resistance substrate silicon: its resistivity is above 500ohm.cm. T...

AI Technical Summary

Problems solved by technology

[0005] 3. High-resistance SOI substrate: This type of substrate has structural advantages, but its performance is worse than that of the first type

However, diffusion of oxygen atoms, heat treatment process lead to low surface resistivity of the formed substrate

These two reasons are currently out of control

[0007] 4. On the basis of the third type, the high-resistance SOI substrate type substrate is improved by adding a defect layer. The conventional defect layer growth is easy to introduce impurities, which affects the final performance of the device.

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