Method for doping silicon carbide epitaxial layer region

Abstract

A method for doping a silicon carbide epitaxial layer region, comprising: taking a silicon carbide substrate and cleaning it; epitaxially growing a first intrinsic silicon layer on the surface of the substrate; etching, on the first intrinsic silicon layer A first patterned silicon layer is formed, and the etching depth reaches the surface of the substrate; the first intrinsic silicon layer is melted by increasing the temperature, and the carbon source and the first type of doping source are introduced at the same time, so that the melted first pattern The silicon carbide layer forms first-type doped silicon carbide to form a substrate; a silicon source is fed at low temperature to grow a second intrinsic silicon layer on the substrate; etching, the first type of doped silicon carbide is etched. The second intrinsic silicon layer is etched away, and the etching depth reaches the surface of the first type of doped silicon carbide to form a second patterned silicon layer; the temperature is raised to melt the second patterned silicon layer, and the carbon source is passed into it, and at the same time Passing in the second type doping source to make the melted second patterned silicon layer form the second doped silicon carbide layer; etching the silicon residue to obtain the required complete silicon carbide with the first and second types of regional doping types The epitaxial layer is completed.

Description

technical field [0001] The invention relates to the field of semiconductor technology, and in particular to a method for in-situ region doping in a silicon carbide epitaxial layer. Compared with the traditional method, which is the method of regional ion implantation and high temperature annealing, the present invention can improve the effect of region doping, and No high temperature annealing treatment is required. Background technique [0002] Silicon carbide (4H-SiC, 6H-SiC) is a wide bandgap semiconductor material, its bandgap width can reach 3.0-3.2eV, which is 3 times that of Si, therefore, it has a high critical breakdown electric field (Si 10 times that of Si), high carrier saturation concentration (2 times that of Si) and other characteristics, in addition, it also has the characteristics of high thermal conductivity (3 times that of Si), so it is used in military and aerospace fields for high temperature, high frequency , high-power power electronics, and optoelec...

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Problems solved by technology

Although the implantation process is relatively mature, the process is relatively complicated and expensive, and it is difficult to obtain a good doping effect, and the obtained carrier mobility is very low, which affects the quality of the regional doping and greatly affects the follow-up device performance

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