Tool to provide integrated circuit masks with accurate dimensional compensation of patterns
View Patent ↗Disclosed are mask definition tools, apparatus, methods, systems and computer program products configured to process data representing a semiconductor fabrication mask. A non-limiting example of a method includes performing a decomposition process on a full Transmission Cross Coefficient (TCC) using coherent optimal coherent systems (OCS) kernels; isolating a residual TCC that remains after some number of coherent kernels are extracted from the full TCC; and performing at least one decomposition process on the residual TCC using at least one loxicoherent system. The loxicoherent system uses a plurality of distinct non-coherent kernel functions and is a compound system containing a paired coherent system and an incoherent system that act in sequence. An output of the coherent system is input as a self-luminous quantity to the incoherent system, and the output of the incoherent system is an output of the loxicoherent system.
1. A tool configured to process input data, comprising:
an input to receive input data representing integrated circuit shapes within separate mask regions of a semiconductor fabrication mask for use in optical lithography; and
an output to provide output data representing a mask in which dimensions of mask shapes are compensated on the basis of image content in the vicinity of each mask shape when the mask is projected during optical lithography by a partially coherent imaging system;
the tool being configured to match a partially coherent lithographic image by superposing images from a set of decomposition systems that include a DC-monolinear system, where the DC-monolinear system is configured to use a first aperture transmission and a different second aperture transmission for an output comprising a nonlinear function of an input mask spectrum.
2. The tool as in claim 1 , wherein the tool is configured to form a residual Transmission Cross Coefficient (TCC) by subtracting an approximate TCC that is produced by at least one of the decomposition systems from the TCC of the partially coherent imaging system, and where the DC-monolinear system is configured to create a holographic interference pattern between mask images transmitted by a first constituent coherent system whose aperture transmission matches a critical axis of the residual TCC, and mask images transmitted by a second constituent coherent system.
3. The tool as in claim 2 , where the tool is configured to assign transmission values to an aperture of the second constituent coherent system that minimize a total squared magnitude of a portion of the residual TCC that is left unmatched by the DC-monolinear system.