SOI MOSFET WITH BURIED BODY STRAP BY WAFER BONDING

Although the buried oxide in the silicon-on-insulator (SOI) MOSFET mak es possible higher performance circuits, it is also responsible for va rious floating body effects, including the kink effect, drain current transients, and history dependence of output characteristics. It is di fficult to incorporate an effective contact to the body because of Lim itations imposed by the SOI structure, One candidate, which maintains device symmetry, is the lateral body contact. However, high lateral bo dy resistance makes the contact effective only in narrow width devices , in this work, a buried lateral body contact in SOI is described whic h consists of a low-resistance polysilicon strap running under the MOS FET body along the device width. MOSFET's with effective channel lengt h of 0.17 mu m have been fabricated incorporating this buried body str ap, showing improved breakdown characteristics. Low leakage of the sou rce and drain junctions demonstrates that the buried strap is compatib le with deep submicron devices. Device modeling and analysis are used to quantify the effect of strap resistance on device performance. By a ccounting for the lateral resistance of the body, the model can be use d to determine the maximum allowable device width, given the requireme nt of maintaining an adequate body contact.