On-Current Enhancement in TreeFET by Combining Vertically Stacked Nanosheets and Interbridges

The TreeFET channel, which is a combination of vertically stacked nanosheet channels and fin-shaped interbridge channels in between the nanosheets, can provide an additional channel conduction area to improve the on-current without increasing the device footprint. To provide on-current enhancement, a minimum height is required for the interbridge that is dependent on the width of the interbridge and the physical gate oxide thickness. Minimizing the threshold voltage difference between the interbridges and the nanosheet channels also plays a crucial role in the optimization of the on-current of TreeFETs. The design criteria for TreeFETs are studied using TCAD simulation of Ge nFETs.