Short wavelength photolithography

After consideration of all factors which limit resolution such as exposure hardware, resist systems, registration, alignment, and linewidth control, there is a general consensus that the useful resolution limit of photolithography may lie somewhere between 0.4 and 0.8 /im and depends on such factors as the implementation of short wavelength UV and the ability to accurately place images from a projection tool onto a silicon wafer. 

Microposit 2400 resist, manufactured by Shipley Co., has been shown to be sensitive at this short wavelength ( ) and is being employed with the deep UV stepper. We report here the results of resist profile modeling for submicron photolithography at 248 nm. Various model parameters needed as input data were measured to characterize exposure and development of the resist. 

Other applications of F2 lasers are optical pumping of Br and OCS Raman lasers, NO laser, and solid state NdiLaFs laser. Using the high photon energy and short wavelength, photolithography, laser chemical vapor deposition (C VD), laser ablation, etc. are demonstrated. 

X-RAY LASERS are devices that amplify very short wavelength radiation along a well-defined direction in order to obtain an intense, collimated, and coherent beam of monochromatic and penetrating emission. Such a radiation source can be used for photolithography of microcircuitry, holographic microscopy of cellular structure in biology, plasma diagnostics, and many other scientific and technical purposes. 

The SAW wavelength is on the same order of magnitude as line dimensions produced by photolithography and the lengths for both short and long delays are achievable on reasonably sized substrates. 

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