The performance benefits of multilayer resist processes are well known, but because of the additional processing complexity their use has been restricted mainly to lab scale or pilot line environments. More recently a surface sensitive scheme , the so-called DESIRE process, has been developed. It has the potential of reaping the benefits of multilayer resist processes without their process complexity. In this paper a preliminary characterization of the lithographic performance of this process is described. In particular the issues of resolution, focus latitude, exposure latitude and uniformity are examined. When the appropriate silylation and development conditions are used, the data clearly show that a significant improvement in the working stepper resolution can be achieved while maintaining the uniformity across the wafer. In a 0.28 numerical aperture lens stepper, the exposure latitude first becomes the resolution limitation. Using the DESIRE process a five-fold increase in the exposure latitude is achieved as compared to an optimized process using conventional development. As the stepper numerical aperture increases, the focus latitude becomes the limiting factor to resolution. Using the DESIRE process the focus latitude increases nearly two-fold in a 0.35 numerical aperture stepper as compared to conventional processing. This preliminary characterization study shows that the DESIRE process has the potential of extending the useful life of optical projection printers.
Cesar M. Garza,
"Preliminary Performance Characterization Of The DESIRE Process", Proc. SPIE 0920, Advances in Resist Technology and Processing V, (1 January 1988); doi: 10.1117/12.968324; https://doi.org/10.1117/12.968324