Decomposition Algorithm for Double Patterning of Contacts and Via Layers

Abstract:
The Semi Conductors manufacturing processes have been, over the years, striving to shrink the dimensions of the devices that can be realized on silicon wafers from one technology node to the next. Utilization of optical lithography in the manufacturing process has enabled predictable process adjustments that can be put in place to allow for the next generation of smaller silicon devices. However after reaching ArF wavelength for source illumination, it became obvious that moving to the next smaller wavelength would cost a lot. Innovative Resolution Enhancement Techniques had to be researched, developed and implemented to enable the dimension shrink while utilizing the same illumination wavelength. Double patterning is among the techniques that can enable devices of 45nm and below dimensions. The technique relies on decomposing the exposure mask into two masks; each of the decomposed masks will have a relaxed mask features’ pitch compared to the original mask, such that the relaxed pitches are resolvable by the illumination process. In this paper we present an implementation of a fast algorithm for pitch splitting of contact and via layer.