摘要 |
A method for fabricating a buried layer pinched collector bipolar, (BPCB), device, sharing several process steps with simultaneously formed CMOS devices, has been developed. The BPCB device fabrication sequence features the use of field ring regions, placed in an N well region, and located between a base and collector region. The use of the field ring results in an increase in collector-emitter breakdown voltage, as a result of the reduction in local dopant concentration in the N well region. This phenomena, the reduction the local dopant concentration in the N well region, in the vicinity of the field ring region, allows a higher N well dopant concentration to be used, resulting in increased frequency responses, (Ft), of the BPCB device, when compared to counterparts fabricated without the field ring regions, and thus with a lower N well dopant concentration.
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