Influence of phase shift on pattern transfer in x-ray lithography

Fabrication of 0.2 μm large scale integrated circuits using synchrotron radiation x-ray lithography

“…This is because the phase-shifting effect of x rays passing through the absorber patterns enhances resolution. [36][37][38][39][40][41][42][43][44] By optimizing the mask contrast, we expect that SR lithography will meet the resolution requirements for future LSIs for several generations.…”

Resist Modeling Near Resolution And Sensitivity Limits In X -Ray Lithography

“…Fast resists for X -ray lithography require exposure doses around 10 mJ /cm2, which corresponds to an absorbed energy of 30 J /cm3 ( for a 'resist absorption of a = 0.3 am-1). 1…”

“…For alternative sources of soft X -ray radiation with a finite spot size, such as laser -or plasma -focus, source size, source to wafer distance and source divergence are also of importance. Efficient programs [1,2] are available which allow the simulation of these effects; for a synchrotron source and a realistic proximity gaps of 30 microns and a 1.0 to 2.0 nm radiation range, Fresnel diffraction effects are not expected to be the limiting factor for resolution down to 0.15 micron feature size. Estimates for the resolution obtainable with finite spot size sources have been published [3].…”