SOURCE/DRAIN PROTECTION USING A BACKSIDE PLACEHOLDER

Organization Name

INTERNATIONAL BUSINESS MACHINES CORPORATION

Inventor(s)

Biswanath Senapati of Mechanicville NY (US)

SOURCE/DRAIN PROTECTION USING A BACKSIDE PLACEHOLDER

This abstract first appeared for US patent application 18337211 titled 'SOURCE/DRAIN PROTECTION USING A BACKSIDE PLACEHOLDER

Original Abstract Submitted

Embodiments of the invention include a method for fabricating a semiconductor device and the resulting structure. A plurality of nanosheet recesses are formed within a substrate. A placeholder structure is formed on a bottom surface within each nanosheet recess. A first source/drain region is formed within a first nanosheet recess. A second source/drain region is formed within the second nanosheet recess. The semiconductor structure is flipped. The substrate is removed respective to a sidewall spacer of the placeholder structure and a first etch stop layer of the placeholder structure. Backside interlayer dielectric is formed. A backside contact trench to the second source drain region is formed by removing a portion of the backside interlayer dielectric over the second source/drain region and removing exposed portions of the first etch stop layer, the sidewall spacer, and a silicon buffer layer of the placeholder structure. A backside contact is formed within the trench.