Analysis of new high-voltage bipolar Silicon-On-Insulator transistor with fully depleted collector

A new type of high voltage bipolar transistor for implementation in SOI material (Silicon-On-Insulator) has been developed. It is shown by measurements on fabricated structures and by numerical device simulations that the current drive capability of such a transistor is comparable to what has been achieved in a conventional transistor with buried layer and plug or in any optimized lateral transistor with buried emitter and collector layers. The new type of transistor designed in a few micrometer thick silicon layer has a breakdown voltage BV/sub CEO/ in excess of several hundreds volts and also a remarkably high Early voltage of about 400 volts. This unique Early voltage is also explained in detail by a new analytical model. The transistor is expected to have a strong impact on the feasibility to realize mixed analog and digital signal circuits with high and low voltage functions on the same chip.<
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