Bipolar transistor with isolation and direct contacts

US7217988B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• David C. Ahlgren · Wappingers Falls, US
• Gregory G. Freeman · Hopewell Junction, US
• Francois Pagette · Fishkill, US
• Christopher M. Schnabel · Poughkeepsie, US
• Anna W. Topol · Jefferson Valley, US

Key dates

• Filing date: Jun 4, 2004
• Grant date: May 15, 2007
• Expiry date: Jun 4, 2024

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D10/891

Abstract

A bipolar transistor has a collector that is contacted directly beneath a base-collector junction by metallization to reduce collector resistance. A conventional reach-through and buried layer, as well as their associated resistance, are eliminated. The transistor is well isolated, nearly eliminating well-to-substrate capacitance and device-to-device leakage current. The structure provides for improved electrical performance, including improved fT, Fmax and drive current.