High Performance Air Turbulence Compensated Interferometer For Integrated Circuit and Flat Panel Display Manufacturing

This proposal addresses a key issue for flat panel display printers which will aid the poduction of higher quality displays and enable the US manufacturers to capture a significant market share. This issue, stage precision, is required for good overlay and stitching performance, and translates directly into improved grayscale performance and higher pixel resolution. Existing flat panel printers have a stage precision of approximately 150 nm, and air turbulence is the major contributing factor to that budget. Dual-wavelength interferometry provides a way to compensate for air turbulence. This approach is based on the simultaneous measurement of the optical path at two widely-based wavelengths. The difference between the path length at the two wavelengths is related to the amount of air in the path. The innovation developed at SPARTA is the use of second harmonic interferometry to measure the path length difference directly and provide a precise determination of the air content of the beam path (4 nm 3 sigma). This system is currently being developed for application to IC manufacturing. The payoff will be the future ability to fabricate higher quality displays using the existing MRS Flat Panel Printer. Because display quality is a key selling point for high end laptop computers, it is a highly leveraged factor in the sales of consumer goods. Access to high quality displays by US manufacturers will provide a valuable boost to US manufacturer sales for consumer electronics. Anticipated Military Benefits/Potential Commercial Applications of the Research Development: Flat panel displays are a key component of military and commercial portable systems. Currently, nearly all flat panel displays are made in the far east. The high capital costs of setting up a flat panel display manufacturing line have prohibited setting up production in the US to meet our low volume military needs. This work could result in a significant advantage for US display manufacturers leading to a significant commercial market share and assuring reliable supply of this critical component for military uses.