Method for growing high-resistance thick layer silicon epitaxy on 6-inch heavily As-doped silicon substrate

Abstract

The invention relates to a method for growing a high-resistance thick layer silicon epitaxy on a 6-inch heavily As-doped silicon substrate. In the method, a normal-pressure flat plate type epitaxial furnace is adopted. The method comprises the following steps: (1) corroding an epitaxial furnace base by using hydrogen chloride with the purity of not less than 99.99 percent at a high temperature; (2) loading a silicon substrate sheet in the epitaxial furnace, purging a cavity of the epitaxial furnace for 8-10min by sequentially using nitrogen and hydrogen with purities of not less than 99.99 percent; (3) performing in-situ corrosion on the surface of the silicon substrate sheet by using hydrogen chloride gas; (4) purging the surface of the silicon substrate sheet by large-flow hydrogen; (5) growing an intrinsic epitaxial layer on the substrate by using non-doped trichlorosilane; (6) growing a doped epitaxial layer; and (7) cooling after the epitaxial layer reaches a preset temperature during growing. The method has the beneficial effects of being used for successfully preparing a high-resistance thick layer silicon epitaxy structure with thickness non-uniformity of less than 1 percent and specific resistance non-uniformity of less than 1 percent, without defects of a stacking fault, dislocation, a slip line and fog, with an optimal transition region width of less than 4 micrometers, good uniformity and a narrow transition region, and capable of completely meeting a requirement of a power MOS device on a silicon epitaxial material in an aspect of a parameter.

Description

technical field [0001] The invention relates to a semiconductor material preparation technology, in particular to a method for growing high-resistance thick-layer silicon epitaxy on a 6-inch heavy arsenic-doped substrate. Background technique [0002] High-resistance thick-layer silicon epitaxial wafers generally refer to epitaxial wafers with a thickness ranging from 30 to 150 μm and a resistivity greater than 15W×cm. This type of epitaxial wafer is mainly used for MOSFETs and power amplifier devices. As the diameter of silicon wafers continues to increase, it becomes more difficult to control the uniformity and defects within the wafer. High-resistance thick-layer silicon epitaxial wafers usually choose arsenic-doped and antimony-doped substrates, in which arsenic-doped (r: 0.002~0.004W×cm) silicon substrates are compared with antimony-doped (r: 0.01~0.02W×cm) The silicon substrate has a lower resistivity, which can reduce the forward conduction voltage drop when applied ...

AI Technical Summary

Problems solved by technology

For the growth of a thick-layer high-resistance epitaxial structure on a 6-inch heavily doped silicon substrate, due to the longer process time required and the increase in the surface size of the epitaxial wafer, the edge position of the substrate is more affected by the inactive doping effect of impurities. Therefore, it is more difficult to prepare epitaxial layers with high resistivity uniformity and narrow transition regions

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