Shallow buried channel gated BJT on TFSOI substrate

The gated BJT structure is inherently suitable for SOI BiCMOS technology. However, being a surface channel device, it suffers higher noise and degraded carrier transport. In this study, a novel shallow buried channel design on TFSOI is proposed. Devices with various geometries have been fabricated with a simple CMOS-compatible process. These devices have low turn-on voltage, ideal BJT I-V characteristics with current gain higher than 1000, and a maximum transconductance of 290 mS/mm for a 0.5 μm channel length and 15 nm gate oxide. Careful measurements show that an order of magnitude improvement in noise performance can be expected from the buried channel operation. These devices are suitable for various BiCMOS applications.