发明名称 |
Epitaxial cleaning process using HCL and N-type dopant gas to reduce defect density and auto doping effects |
摘要 |
An epitaxial layer is formed on a P type silicon substrate in which a plurality of P+ buried layer regions, a plurality of N+ buried layer regions, and a P+ field layer region occupying most of the substrate surface are diffused. The substrate is loaded in a reactor with a carrier gas. The substrate is pre-baked at a temperature of approximately 850° C. As the substrate is heated to a temperature of 1050° C., N+ dopant gas is injected into the carrier gas to suppress auto doping due to P+ atoms that escape from the P+ buried layer regions. The substrate is subjected to a high temperature bake cycle in the presence of the N+ dopant gas. A first thin intrinsic epitaxial cap layer is deposited on the substrate, which then is subjected to a high temperature gas purge cycle at 1080° C. A second thin intrinsic epitaxial cap layer then is deposited on the first, and a second high temperature gas purge cycle is performed at 1080° C. Then an N-epitaxial layer is deposited on the second cap layer at 1080° C. The harmful effects of a dip in the dopant concentration profile at the bottoms of the collectors of the NPN transistors are avoided by the process. |
申请公布号 |
US6274464(B2) |
申请公布日期 |
2001.08.14 |
申请号 |
US20010771428 |
申请日期 |
2001.01.26 |
申请人 |
TEXAS INSTRUMENTS INCORPORATED |
发明人 |
DROBNY VLADIMIR F.;BAO KEVIN X. |
分类号 |
H01L21/8249;(IPC1-7):H01L21/20;H01L21/36 |
主分类号 |
H01L21/8249 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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