<title>Enhanced lumped parameter model for photolithography</title>

Enhancements to the lumped parameter model for semiconductor optical lithography are introduced. These enhancements allow the lumped parameter to calculate resist sidewall angle as well as resist linewidth in an approximate but extremely fast manner. The model shows the two main contributors to resist slope: development effects due to the time required for the developer to reach the bottom of the photoresist, and absorption effects resulting in a reduced exposure at the bottom of the resist.