High performance integrated circuit having modified extrinsic base

US4752817A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• John S. Lechaton · Wappingers Falls, US
• Philip M. Pitner · Wappingers Falls, US
• Gurumakonda R. Srinivasan · Poughkeepsie, US

Key dates

• Filing date: Oct 21, 1986
• Grant date: Jun 21, 1988
• Expiry date: Oct 21, 2006

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D10/441

Abstract

There is described a process for making a high performance NPN bipolar transistor functioning in a current switch logic circuit. A bipolar transistor is formed within an isolated region of a monocrystalline silicon body wherein the transistor includes an N+ subcollector, an N+ collector reach-through which connects the subcollector to a major surface of the silicon body, a P base region above the subcollector and adjacent to the reach-through region, an N+ emitter region within the base region and extending from the major surface. The base region includes an intrinsic base region located below the emitter region and an extrinsic region located extending from the major surface and adjacent to the emitter region. The extrinsic base preferrably completely surrounds or rings the emitter region. A mask is formed above the major surface and the mask has openings therein only in the areas above major portions of the extrinsic base regions. A P+ type region is formed in the extrinsic base region by ion implanting with a P type dopant to a depth of less than the depth of the N emitter region followed by a short thermal anneal to activate the P dopant. Electrical ohmic contacts are made to t…