Wayne E. Feely

Chemically amplified resists for I-line and G-line applications

This paper describes the evaluation of several phenothiazine and benzophenothiazine derivatives which are useful as i-line and g-line photosensitizers for a class of chemically amplified crosslinked resists. Data supporting an electron transfer mechanism of sensitization from the excited state of the sensitizer to the acid generator are provided. Initial lithographic screening demonstrates the potential for both high sensitivity and submicron resolution in these systems.

Aqueous Base Developed, Single Level Resist For Submicron X-Ray Lithography

The x-ray lithographic performance of a new, experimental negative acting, single level resist has been investigated. Unlike other negative x-ray resists, which are solvent developed, the new resist is developed with aqueous base. This results in very low image swelling and allows high resolution, high aspect ratio, negative resist images to be obtained with a conventional palladium anode x-ray source of wavelength 4.37 A. The x-ray sensitivity of the resist to Pd x-rays is about 40 mJ/cm2, sufficient to allow a throughput of 5 to 10 wafer levels per hour , when used in conjunction with an x-ray stepper powered by a conventional, fixed anode, 6kW x-ray source. Using this production oriented x-ray stepper and suitable x-ray masks, submicron resolution is demonstrated in single level resist layers of 1 to 2 pm thickness over various substrates and topographies. Dry etch resistance under Si, poly Si and Al etching conditions is evaluated. Thermal stability and DUV hardening characteristics are also investigated. The speed and excellent processing characteristics of the resist make it very attractive for hybrid x-ray/optical lithography applications, using conventional x-ray lithography systems.