Browse Prior Art Database

Sidewall Contact Transistor Structure and Process

IP.com Disclosure Number: IPCOM000039469D
Original Publication Date: 1987-Jun-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Monkowski, MD: AUTHOR

Abstract

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 [3] to make the sidewall contact. Fig. 1 shows a top view of the transistor structure formed by use of references [1 through 4].

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Sidewall Contact Transistor Structure and Process

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 [3] to make the sidewall contact.

Fig. 1 shows a top view of the transistor structure formed by use of references [1 through 4]. Identified are the base contact 1, base sidewalls 2, silicon pedestal 3 and the emitter opening 4. The multiple emitter structure shown in Fig. 2 may also be obtained by employing multiple base contact stripes across the pedestal shown in Fig. 1. The emitters are designated 5 and 6 in Fig. 2. Fig. 3 shows the completed sidewall contact transistor structure prior to opening of contact holes and metallization. Identified in this top view of the structure are the emitter contact 7, base contact 8 and the emitter/base spacer 9. A lateral transistor can also be made using this process by appropriate changes in mask and etch of the base sidewall. References D. D. Tang, V. J. Silvestri, H...