A differential-height-mesa buried body tie SOI process

A low-area penalty method of contacting the floating body of thin-film SOI (silicon-on-insulator) devices has been devised. By contacting the otherwise floating body, its potential can be fixed and the well-documented issues of bipolar snapback and kink arising from impact ionization may be mostly or entirely mitigated. This body tie is fabricated under a conventional LOCOS field isolation structure. An added benefit of this process approach is that mesas of different thicknesses may be readily fabricated so that a mixture of fully depleted and partially depleted transistors can be built on a common substrate simultaneously