A Comparison of PNP and NPN SiGe Heterojunction Bipolar Transistors Fabricated by Ge(+)-implantation

Abstract

A study is made of npn and pnp SiGe heterojunction bipolar transistors produced using Ge+-implantation. The Ge+ is implanted into a complementary bipolar process after active area formation. Increased collector currents are observed in both npn and pnp transistors due to the presence of the Ge. The implanted Ge+ has opposing effects on the emitter dopant diffusion increasing the arsenic diffusion coefficient in the npn devices and retarding the boron diffusion coefficient in the pnp devices.