Practical application of full-feature alternating phase-shifting technology for a phase-aware standard-cell design flow

Abstract

As the semiconductor industry enters the subwavelength era where silicon features are much smaller than the wavelength of the light used to create them, a number of “subwavelength” technologies such as Optical Proximity Correction (OPC) and PHase-Shifting Masks (PSM) have been introduced to produce integrated circuits (ICs) with acceptable yields. An effetive approach to subwavelength IC production includes a combination of these techniques, including OPC and PSM. Nevertheless, as we approach silicon features of 0.10 μ and below, Alternating PSM (AltPSM ICs must guarantee correct generation of AltPSM layouts, maintain or improve today's design productivity, and leverage existing tools and flows. The implementation of such a methodology becomes more complex as phase shifting is applied to all critical features, including those outside of transistor gates. In this paper, we present a methodology targeted for standard-cell or structured-custom design styles. We also present examples of designs that start from standard-cells created in a manner in which all issues regarding generation of AltPSM are effectively considered, and are used in a typical cell-based (synthesis-Automatic Place & Route) flow to produce design layouts that are ready for cost-effective silicon manufacturing.