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

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 effective approach to subwavelength IC production includes a combination of these techniques, including OPC and PSM. Nevertheless, as we approach silicon features of 100 nm and below, Alternating PSM (AltPSM) becomes a critical part of the technology portfolio needed to achieve IC requirements. An effective EDA methodology that generates AltPSM ICs must guarantee correct generation of AltPSM layouts, maintain 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 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 then used in a typical cell-based (synthesis-automatic place and route) flow to produce design layouts that are ready for cost-effective silicon manufacturing.