SOI and device scaling

In the past five years, impressive progress has been made in SOI materials, device and process demonstrations, and product research, yet SOI IC technology remains a promise more than a reality. An important reason is that the rate of bulk technology scaling, in terms of gate length, gate oxide thickness, threshold voltage (V/sub t/), and performance has exceeded earlier expectations (Hu, 1995). In an environment of rapidly advancing bulk technology, it was difficult to overcome the concern over the known and unknown risks of adopting SOI technology, as it was not known how the situation might change with future scaling. This paper attempts to highlight some considerations in three phases of device scaling-when bulk device scaling may proceed rapidly, slowly, and with extreme difficulty.