Gate cut first isolation formation with contact forming process mask protection

Abstract

A method, FET structure and gate cut structure are disclosed. The method forms a gate cut opening in a dummy gate in a gate material layer, the gate cut opening extending into a space separating a semiconductor structures on a substrate under the gate material layer. A source/drain region is formed on the semiconductor structure(s), and a gate cut isolation is formed in the gate cut opening. The gate cut isolation may include an oxide body. During forming of a contact, a mask has a portion covering an upper end of the gate cut isolation to protect it. The gate cut structure includes a gate cut isolation including a nitride liner contacting the end of the first metal gate conductor and the end of the second metal gate conductor, and an oxide body inside the nitride liner.

Dependencies are inferred from the claim text.