Patent · US Expired

Phase shifting design and layout for static random access memory

US6681379B2 · kind B2 · utility

16Cited by
66References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 15, 2001
Grant dateJan 20, 2004
Priority date—
Expiry dateFeb 13, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F7/70466
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Methods and apparatuses for fully defining static random access memory (SRAM) using phase shifting layouts are described. The approach includes identifying that a layout includes SRAM cells and defining phase shifting regions in a mask description to fully define the SRAM cells. The phase conflicts between adjacent phase shifters are resolved by selecting cutting patterns designed for the SRAM shape and functional structure. Additionally, the transistor gates of the SRAM cells can be reduced in size relative to the original SRAM layout design. Thus, an SRAM cell can be lithographically printed with small, consistent critical dimensions including extremely small gate lengths resulting in higher yields and improved performance.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.