摘要 |
By providing a novel bipolar device design implementation, a standard CMOS process can be used unchanged to fabricate useful bipolar transistors and other bipolar devices having adjustable properties by partially blocking the P or N well doping used for the transistor base. This provides a hump-shaped base region with an adjustable base width, thereby achieving, for example, higher gain than can be obtained with the unmodified CMOS process alone. By further partially blocking the source/drain doping step used to form the emitter of the bipolar transistor, the emitter shape and effective base width can be further varied to provide additional control over the bipolar device properties. The embodiments thus include prescribed modifications to the masks associated with the bipolar device that are configured to obtain desired device properties. The CMOS process steps and flow are otherwise unaltered and no additional process steps are required.
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