Sacrificial layer fin isolation for fin height and leakage control of bulk finFETs

摘要

The present disclosure relates to a structure and method for fin isolation in bulk FinFETs. A sacrificial portion is formed between the actual fin and the substrate, which gets selectively removed at a later stage of processing to reveal a cavity which extends all the way under the fin. This helps prevent source/drain leakage as there is no path for current flow between the fin and bulk substrate. Furthermore, this method of formation helps in precise control of fin-height in bulk FinFETs.