Two-color self-aligned double patterning (SADP) to yield static random access memory (SRAM) and dense logic

• Main Authors: Lie, Fee Li, Xu, Yongan, Wong, Robert C, Shao, Dongbing
• Format: Patent
• Language: English
• Published: 11.07.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

First lithography and etching are carried out on a semiconductor structure to provide a first intermediate semiconductor structure having a first set of surface features corresponding to a first portion of desired fin formation mandrels. Second lithography and etching are carried out on the first intermediate structure, using a second mask, to provide a second intermediate semiconductor structure having a second set of surface features corresponding to a second portion of the mandrels. The second set of surface features are unequally spaced from the first set of surface features and/or the features have different pitch. The fin formation mandrels are formed in the second intermediate semiconductor structure using the first and second sets of surface features; spacer material is deposited over the mandrels and is etched back to form a third intermediate semiconductor structure having a fin pattern. Etching is carried out on same to produce the fin pattern.