High-Resolution Imagery: The Matching Of Optical And Resist Systems In The Mid-UV

The demands of the semiconductor industry for super high-pattern density with ever-reducing feature sizes, places requirements on semiconductor equipment manufacturers to produce lithographic tools of increasingly challenging specifications. Currently, the tool of choice for submicron production lithography is the 5X stepper system. The pressure to increase the performance of this type of system is causing lens manufacturers to evaluate optical systems that have higher Na values operating at shorter wavelengths than ever before. Different equipment manufacturers offer many combinations of x , Na, and image field size. They are all balancing these variables to produce a specification that their own lens fabricators have the manufacturing skills to build. This paper briefly discusses the design and testing of a lens, and the matching of the photoresist and its processing to the lens operating at I-line, in order to maintain and replicate the high-quality submicron image.