Integrated transistor and manufacturing process therefor.

摘要

A transistor has a base region in a column (42) of selectively grown epitaxial silicon isolated from adjacent structures in a field of oxide. A layer of doped polysilicon which is embedded in the insulating material surrounding the column of epitaxial silicon forms a sidewall base contact. The collector contact is formed of another column (38) of selectively grown epitaxial silicon grown over and in electrical contact with a buried layer (34) underlying the first column of epitaxial silicon. The emitter region (56) is implanted into the top of column doped as the base region. The base contact can be a buried polysilicon layer or epitaxial silicon which is grown over oxide by uncontrolled growth following controlled selective growth. The transistor can be made by forming a layer of oxide, etching two holes in it and growing the epitaxial silicon in the holes. Thereafter, in one embodiment, the oxide is etched back to expose the sidewalls of the columns and polysilicon is deposited, doped and etched to form the sidewall base contacts. In another embodiment, the base contact is formed by allowing the selectively grown epitaxial silicon to grow laterally out over the top of the oxide layer in the columns of epi are grown. The structure is then planarized, the emitter region is formed, and the contact holes are etched and contacts are formed.