A Perspective on SOI Symmetric Lateral Bipolar Transistors for Ultra-Low-Power Systems

The reasons why state-of-the-art vertical bipolar circuits dissipate very high power are explained. The recent advent of SOI symmetric lateral bipolar transistors invites us to rethink bipolar as a high-speed but low-power technology. Integrated Injection Logic (I
²
L) and complementary bipolar (analogous to CMOS) circuits in SOI lateral bipolar offer huge design windows for power versus performance tradeoff, suggesting the possibility of ultra-low-power systems with embedded high-speed cores. I
²
L SRAM cells could be more than twice as dense as CMOS SRAM cells. The SOI substrate offers a fourth device terminal that can be used to induce narrow-gap-base HBT-like I-V characteristics, which should further improve the power-performance of circuits in SOI lateral bipolar. Fin-structure devices enable significant improvement in f
_max
for RF and high-frequency applications. The process technology for SOI lateral bipolar is compatible with CMOS. The Si-OI version is definitely much less complex than CMOS.