Characterization of transistors fabricated in solid-phase epitaxially regrown material

Solid phase isolated regrowth for radiation immune technology (SPIRRIT) incorporates lateral epitaxial overgrowth into a standard CMOS process to improve circuit speed and immunity to latchup and single event upset. In previous work, a high-dose ion mixing implant was used to disrupt the continuity of the native oxide layer between the substrate and the deposited silicon film, permitting epitaxial alignment of the deposited layer. However, residual implantation damage attributed to this implant formed donor states which provided a leakage path in the channel of the n-MOSFETs. It was subsequently demonstrated that rapid thermal processing (RTP) can be substituted for the high-dose silicon implant. In the present work, the authors evaluate the effect of variations in the RTP cycle on MOSFET parameters, and demonstrate substantial improvement in the performance of the SPIRRIT devices when RTP is incorporated in lieu of a high-dose ion-mix implant to agglomerate the native interfacial oxide. The application of this process was demonstrated by fabricating devices comparable in performance to concurrently fabricated bulk transistors