METHOD AND APPARATUS FOR DETERMINING AN OPTICAL THRESHOLD AND A RESIST BIAS

摘要

One embodiment of the present invention provides techniques and systems for determining modeling parameters for a photolithography process. During operation, the system can receive a layout. Next, the system can determine an iso focal pattern in the layout. The system can then determine multiple aerial image intensity values in proximity to the iso focal pattern by convolving the layout with multiple optical models, wherein the multiple optical models model the photolithography process's optical system under different focus conditions. Next, the system can determine a location in proximity to the iso focal pattern where the aerial image intensity values are substantially insensitive to focus variations. The system can then use the location and the associated aerial image intensity values to determine an optical threshold and a resist bias. The optical threshold and the resist bias can then be used for modeling the photolithography process.