Patent ID: 7226835
Filing Date: 2007-06-05
Classification: H01L

Abstract:
1. A method for forming emitter contact structures for a bipolar transistor technology, comprising: providing a collector region; providing a base region adjacent the collector region; providing an emitter region comprising a total emitter area (A providing a required range for a current gain (H determining a first current ratio of said bipolar transistor wherein said first current ratio is given by the ratio of a base current density in said emitter contact region of said bipolar transistor to a collector current density of said bipolar transistor (J determining a second current ratio of said bipolar transistor wherein said second current ratio is given by the ratio of a base current density in said emitter non-contact region of said bipolar transistor to the collector current density of said bipolar transistor (J determining a range for an emitter area ratio of the total emitter area to the emitter non-contact region from said first current ratio and said second current ratio; determining a required range of emitter contact area A forming said emitter contact structure within said required range.