Date on Master's Thesis/Doctoral Dissertation
Electrical and Computer Engineering
Integrated circuits--Design and construction; Integrated circuits industry--Technological innovations
Lithographic processes for printing device structures on integrated circuits plays a major role in the semiconductor industry. This project aims at designing and fabricating a programmable mask for a direct write lithography system which can achieve higher throughput at a reasonable cost for the semiconductor industry in the future. The device has apertures of different sizes which can be used as programmable masks by opening and closing the shutters over them. The shutters are actuated by electrostatic comb drive actuators which are microfabricated nickel structures electroplated on copper over a sacrificial layer and are released later by a sacrificial etch. The high aspect ratio apertures are etched through the wafer using deep reactive ion etching (DRIE) stopping at the oxide layer. The optical image of the developed photoresist that was exposed through the apertures resembles almost identical feature size and linewidth measurement of the pattern exposed. Future developments regarding the optimization of micromechanics and optics have also been discussed.
Pharas, Kunal 1979-, "A programmable mask for direct write lithography." (2006). Electronic Theses and Dissertations. Paper 1128.