Shanghai Hua Hong Nec Electronics Company, Limited

Jiong Xu

Wensheng Qian

Fan Chen

Tzuyin Chiu

Haifang Zhang

YungChieh Fan

TungYuan Chu

This invention disclosed a manufacturing approach of collector and buried layer of a bipolar transistor. One aspect of the invention is that a pseudo buried layer, i.e, collector buried layer, is manufactured by ion implantation and thermal anneal. This pseudo buried layer has a small area, which makes deep trench isolation to divide pseudo buried layer unnecessary in subsequent process. Another aspect is, the doped area, i.e, collector, is formed by ion implantation instead of high cost epitaxy process. This invention simplified the manufacturing process, as a consequence, saved manufacturing cost.

Manufacturing approach for collector and a buried layer of bipolar transistor

This invention disclosed a novel manufacturing approach of collector and buried layer of a bipolar transistor. One aspect of the invention is that an oxide-nitride-oxide (ONO) sandwich structure is employed instead of oxide-nitride dual layer structure before trench etching. Another aspect is, through the formation of silicon oxide spacer in trench sidewall and silicon oxide remaining in trench bottom in the deposition and etch back process, the new structure hard mask can effectively protect active region from impurity implanted in ion implantation process.

Growing community of inventors

Shanghai, China

Jiong Xu