摘要 |
High-voltage bipolar transistors (30, 60) in silicon-on-insulator (SOI) integrated circuits are disclosed. In one disclosed embodiment, an collector region (28) is formed in epitaxial silicon (24, 25) disposed over a buried insulator layer (22). A base region (32) and emitter (36) are disposed over the collector region (28). Buried collector region (31) are disposed in the epitaxial silicon (24) away from the base region (32). The transistor may be arranged in a rectangular fashion, as conventional, or alternatively by forming an annular buried collector region (31). According to another disclosed embodiment, a high voltage transistor (60) includes a central isolation structure (62), so that the base region (65) and emitter region (66) are ring-shaped to provide improved performance. A process for fabricating the high voltage transistor (30, 60) simultaneously with a high performance transistor (40) is also disclosed.
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