Lithographers Get Etch Simulation

摘要

Although optical lithography simulation has existed for years, it has fallen short of meeting all of the lithography engineer's needs. Traditional simulations begin with a design layout and model the optical and chemical processes involved in reproducing the design as a three-dimensional photoresist pattern. The model, however, provides no information about the resist pattern's impact on the final etched pattern's quality. For this, a model is needed that also provides etch simulation. Etch simulation is one of the industry's Holy Grails ― and seemingly just as unattainable. Considerable work has been devoted to it, mostly in academia and at research labs, with disappointing results, and no useful software capable of solving major problems has emerged. The reason is simple: Etch simulation is incredibly complicated because of the many variables that must be modeled, together with their various interactions.