Trigate FET Device Characteristics Improvement Using a Hydrogen Anneal Process With a Novel Hard Mask Approach

It is reported that hydrogen anneal after fin formation improves the multigate MOSFET I
_on
/I
_off
ratio. However, a higher anneal temperature also results in silicon loss from the fins, thereby reducing the effective width of the device, which results in drive current degradation. This, in turn, offsets the improved mobility-driven drive current gain. A novel hard-mask-based process was developed to retain the trigate fin height after hydrogen anneal. This process demonstrated improved device characteristics for trigate FET devices, particularly for the short-channel devices.