Silicon-germanium heterobipolar transistor with a step-wise graded base

US6255674A · kind A · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Johann-Friedrich Luy · Ulm, DE
• Helmut Jorke · Gerstetten, DE

Key dates

• Filing date: Jun 1, 1999
• Grant date: Jul 3, 2001
• Expiry date: Jun 1, 2019

Classification

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

Abstract

A silicon-germanium heterobipolar transistor has a silicon emitter 1, a silicon-germanium base 2 and a silicon collector 3 such that, starting from the emitter 1, the base 2 includes a change in the Ge content in the form of a step-wise increase, and a likewise step-wise, but opposing, change in the doping concentration, with a step height that is larger, seen in terms of energy, than the energy of the optical phonon energy of the semiconductor material.