SILICON-CARBON LAYER IN EMITTER FOR SILICON-GERMANIUM HETEROJUNCTION BIPOLAR TRANSISTORS

摘要

This invention provides an effective means and apparatus for allowing higher operational frequencies in heterojunction bipolar transistors by trapping silicon interstitial atoms (402) and thereby preventing transient enhanced diffusion of boron in the transistor. The invention further provides for selective placement of a carbon layer (404) in the emitter region (406) of a heterojunction bipolar transistor. Such a layer (404) is capable of effectively eliminating transient enhanced boron diffusion without undesirable performance consequences.