Modern lithography techniques

This paper reports the development trends of modern lithography techniques. As a mainstream technique for VLSI fabricator, the optical lithography is advancing towards its resolution limitation; meantime, it faces the technical challenge from VLSI fabricating industry more and more. Today, the resolution of optical lithography is not enough to satisfy the fast development requirements of semiconductor industry even if the complex RET (Revolution enhancement techniques) are used in the optical lithography. Hence the NGL (Next generation lithography) techniques, such as XRL (X-ray lithography), SCALPEL (Scanning anger limited project electronic beam lithography), EBDW (Electronic beam direction writing), EUVL (Extreme ultraviolet lithography), and IPL (Ion beam project lithography) will be introduced into VLSI fabricator application for 100-70 nm line-width. Based on the NGL technique development trends and in view of the multiplicity of market inquiry, authors think every NGL technique will have its survival space. However, when the characteristic width of lithography advanced into nano-meter scale (≤ 100 nm), only the lithography imaging at atomic level will be the last winner. (authors)