Stacked transistor isolation features and methods of forming the same

Abstract

Methods of forming a stacked transistor are provided. One representative method may include patterning a first dummy nanostructure, a second dummy nanostructure, and a semiconductor nanostructure. The semiconductor nanostructure may be disposed between the first dummy nanostructure and the second dummy nanostructure. The first dummy nanostructure may comprise a first semiconductor material and the second dummy nanostructure may comprise a superlattice structure. The representative method may also include performing an etching process that simultaneously recesses the first dummy nanostructure to form a sidewall recess and removes the second dummy nanostructure to form an opening. The etching process selectively etches the superlattice structure at a faster rate than the first semiconductor material. The representative method may further include forming an inner spacer and an isolation structure in, respectively, the sidewall recess and the opening.