Methods for measurement of development parameters in the manufacturing line for use in photolithography modeling

One of the outstanding problems of photolithography is the measurement of development parameters, particularly in one's own manufacturing line. We present an inexpensive practical method for obtaining values of development parameters for use in photolithography modeling. The method utilizes the actual production equipment used in the fab, as well as the computer modeling package for which the development parameters are being collected. In addressing experimental geometries with which one may carry out such data collection, we discuss the critical issue of standing waves and their impact on measurement accuracy. Two techniques are presented for solving the problem of standing waves and their extreme impact on the quality of collected data. One involves creating a photoactive component latent image in which there are no standing waves. The other is a means by which development parameters may still be obtained for situations such as photolithography of thin film magnetic recording heads, where the standing waves may not necessarily be deconvolved from the development process or data collection. Development parameters using 1.15 μm of AZ 4110 resist on a NiFe substrate were measured using the latter technique