Method for preparing high-resistivity silicon chip

Abstract

The invention provides a method for preparing a high-resistivity silicon structure, which comprises the following steps of: providing a P-type silicon structure having medium doping concentration and the initial resistivity of 200 to 1,000ohm-cm; and then performing thermal treatment on the silicon structure to produce oxythermal donors so as to counteract a part of or all cavities in the silicon structure. In the method of the invention, the P-type chip with the medium doping concentration and not high resistivity is first provided, and then is subjected to the thermal treatment, and the time of the thermal treatment process is controlled to prevent the production of excessive oxythermal donors in the thermal treatment process; and as the doping concentration of the first provided chip is medium, the properly-produced oxythermal donors can counteract a part of or all the cavities in the chip for the P-type chip to further remarkably increase the resistivity of the chip. Through the method of the invention, the chips with the resistivity of higher than 1,000ohm-cm can be obtained.

Description

technical field [0001] The invention relates to the technical field of semiconductor material manufacturing, in particular to a method for preparing a high-resistivity silicon wafer. Background technique [0002] Recently, the use of such wafers in the high-resistivity electronics industry has expanded as improvements have been made in the fabrication techniques used to prepare high-resistivity single-crystal silicon wafers. The Czochralski (CZ) method is the most commonly used method for preparing single crystal silicon wafers. But CZ silicon prepared by current techniques is not without limitations. For example, boron is a common impurity in CZ silicon. To grow CZ materials with sufficiently high purity to directly achieve such high resistivity, the boron concentration usually does not exceed 1.3 × 10 13 atoms / cm 3 . However, once such low boron concentrations are achieved, a second challenge exists, namely the presence of thermal donors. The silicon crystal produced...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a method for preparing a high-resistivity silicon structure, so as to solve the problem that the resistivity of the low-doped high-resistivity silicon structure in the prior art will decrease after heat treatment

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