Self-Aligned, Shallow Junction Bipolar Structure
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
The self-aligning base etching scheme described in this article permits the fabrication of very thin base-width bipolar devices, providing both a low extrinsic base resistance and self-alignment of the contact metallurgy to the device contacts. In addition to a narrow intrinsic base, the disclosed device structure also offers improved device performance and density and a planar structure over the device area after metallization. The procedure disclosed consists essentially of diffusing a base in and subsequently removing a portion of it by controlled etch. This involves the addition of a relatively few process steps to the current technology for its implementation, available techniques being employed to form the base and emitter. In reference to Fig.