| 摘要 |
A method for fabricating bipolar transistor having insitu-formed epitaxial base is disclosed herein, the method including the following steps. The first step of the key feature according to one preferred embodiment of the present invention is to use a first epitaxial process to selectively grow an epitaxial collector layer in the etched first oxide layer. The first oxide layer is formed on a buried layer, which is formed on the silicon substrate. Then utilize a second epitaxial process to subsequently grow a first epitaxial-base layer and a second epitaxial-base layer. Particularly the second epitaxial process and the first epitaxial process are performed insitu. Then a patterned oxide layer and poly silicon layer are formed on the second epitaxial-base layer. Followed by etching the poly silicon layer and the patterned oxide layer, the second epitaxial-base layer is implanted, which together with the first epitaxial-base layer are etched. The patterned second and first epitaxial-base layer make up the epitaxial base of the bipolar transistor, the patterned poly emitter layer makes up the emitter of the bipolar transistor, and the epitaxial collector layer makes up the collector of the bipolar transistor. Then a series of traditional processes are used to finish the fabrication of a bipolar transistor.
|
