发明名称 |
Method of manufacturing silicon carbide semiconductor device |
摘要 |
A first impurity region is formed by ion implantation through a first opening formed in a mask layer. By depositing a spacer layer on an etching stop layer on which the mask layer has been provided, a mask portion having the mask layer and the spacer layer is formed. By anisotropically etching the spacer layer, a second opening surrounded by a second sidewall is formed in the mask portion. A second impurity region is formed by ion implantation through the second opening. An angle of the second sidewall with respect to a surface is 90°±10° across a height as great as a second depth. Thus, accuracy in extension of an impurity region can be enhanced. |
申请公布号 |
US9082683(B2) |
申请公布日期 |
2015.07.14 |
申请号 |
US201414147257 |
申请日期 |
2014.01.03 |
申请人 |
Sumitomo Electric Industries, Ltd. |
发明人 |
Ooi Naoki;Shiomi Hiromu |
分类号 |
H01L21/336;H01L29/16;H01L29/66;H01L29/78;H01L21/04 |
主分类号 |
H01L21/336 |
代理机构 |
Venable LLP |
代理人 |
Venable LLP ;Sartori Michael A.;Aga Tamatane J. |
主权项 |
1. A method of manufacturing a silicon carbide semiconductor device, comprising the steps of:
preparing a silicon carbide substrate having a surface; forming an etching stop layer on said surface of said silicon carbide substrate; depositing a mask layer on said etching stop layer; forming a first opening surrounded by a first sidewall in said mask layer; forming a first impurity region having a first conductivity type from said surface to a first depth in said silicon carbide substrate by ion implantation through said first opening; forming a mask portion having said mask layer and a spacer layer by depositing said spacer layer on said etching stop layer on which said mask layer has been provided, after said step of forming a first impurity region, said spacer layer covering said first sidewall and said etching stop layer in said first opening; forming a second opening surrounded by a second sidewall in said mask portion by anisotropically etching said spacer layer in said first opening; and forming a second impurity region having a second conductivity type different from said first conductivity type from said surface to a second depth smaller than said first depth in said silicon carbide substrate, by ion implantation through said second opening, said second sidewall having a substantially uniform thickness across a height as great as said second depth, wherein an ion implantation angle in said step of forming a second impurity region is not smaller than 3° and not greater than 6°, and a surface of said silicon carbide substrate is a (0-33-8) plane of a hexagonal crystal. |
地址 |
Osaka-shi JP |