Optical Measuring Technology Of The Micropatterns

This paper describes three optical measuring machines which have been recently developed for state-of-the-art microlithography, as follows: (1) X-Y measuring machine for checking photomask registration. Utilizing a photoelectric microscope and a laser interferometer, this machine has a repeatability of less than O.lμm, covering a measuring range of 6 inches. (2) Measuring machine for critical line width (1 - 100µm) of photomask. This machine likewise utilizes the latest photoelectric detection technology; it has a repeatability of approximately 0.05µm. (3) Measuring machine for wafer and photomask micropatterns. A newly developed system which makes use of laser beam technology is incorporated in this machine; measurement repeatability is approximately 0.05µm.