Sidewall Contact Transistor Structure and Process
Original Publication Date: 1987-Jun-01
Included in the Prior Art Database: 2005-Feb-01
This article concerns the use of a sidewall contact to make a symmetrical bipolar transistor structure. Existing processes to this end fill the side contact area with polysilicon and require a planarization operation to remove the excess on the surface. The disclosed process uses an RIE (reactive ion etch)-produced sidewall to make contact to the base region of the transistor thereby eliminating the need for planarization. Symmetrical bipolar transistor structures employing sidewall contacts have been described in [1,2]. The main feature of the present process involves the use of the sidewall rail described in  to make the sidewall contact. Fig. 1 shows a top view of the transistor structure formed by use of references [1 through 4].