Book Chapter

Theory and Practicalities of Subwavelength Optical Lithography

Wong, Ban P., Starr, Greg, Cao, Yu, Mittal, Anurag

2004

Overview

Chapter 3 is a tutorial on optical lithography which encompasses the physics and theory of operation including issues associated with advanced processes, and corresponding solutions. It begins with a brief historical perspective, an introduction and simple imaging theory. Then it takes the reader through the challenges for the 100 nm nodes and beyond. This is followed by an overview of the significant process variations, the impact of low‐κ imaging on process sensitivities. A detailed discussion of low‐κ imaging follows, including its effect on depth of focus; exposure tolerance; mask error factor; sensitivity to aberrations; CD variation as a function of pitch; and corner rounding radius. The next topic covered is the state of the art resolution enhancement techniques which will extend the resolution of the current lithography down to a quarter of the wave‐length of the illumination used. This is followed by a discussion of the Physical Design Style Impact on RET and OPC Complexity. The chapter concludes with a look ahead into the future Lithography Technologies—the evolutionary as well as the revolutionary road maps.

• Publisher: John Wiley & Sons, Inc
• Subject: aberrations / annular / antireflective layers / catadioptric system / CD variation / COG / corner rounding radius / depth of focus / direct write e‐beam / EUV lithography / exposure tolerance / layout/resolution‐enhancement interrelationships / low‐κ imaging / mask error enhancement factor / model based OPC / numerical aperture / optical proximity corrections / particle beam lithography / phase shift reticles / PSM / quadrupole and dipole type illuminations / radical design restrictions / resolution enhancement / rules based OPC / sub‐resolution assist features
• ISBN: 9780471466109, 0471466107