CMOS devices fabricated in thin epitaxial silicon on oxide

Summary form only given. The SPIRRIT (solid phase isolated regrowth for radiation immune technology) technique utilizes vertical epitaxial growth and lateral overgrowth by the amorphization and regrowth of a deposited silicon film from a seed window cut in an insulating oxide layer. The SPIRRIT process is fully compatible with standard CMOS production equipment and procedures. CMOS devices were fabricated by SPIRRIT on silicon films that were crystallized by an implant amorphization and thermal anneal process. Similar transistors were also fabricated on bulk material for comparison. Comparisons of SPIRRIT and bulk transistor data show that the SPIRRIT material quality approaches that of the bulk devices. Typical hole mobilities in the SPIRRIT material were 100 cm/sup 2//V sec, compared with 145 cm/sup 2//V sec in bulk MOSFETs. Measured device parameters such as oxide breakdown, subthreshold slope, and transistor current drive were somewhat poorer for the SPIRRIT devices, suggesting that device performance will be enhanced with improved material quality. NMOS SPIRRIT devices exhibited excess leakage currents. The NMOS data indicated the existence of a spurious buried n-type layer in the transistor channel.<
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