Papers by Author: T. Jin

Abstract: Optical surface finish below Ra 10nm can be achieved on a ‘Tetraform C’ grinder of ultra-high stiffness, when grinding a low alloy steel with or without the help of ELID (electrolytic in process dressing). Surface roughness generation modelling has been carried out to predict thepossible surface roughness values. Efforts have been made to transfer the process knowledge to different grinding mode using a rigid 5-axis Edgetek CNC grinder. The effects of material removal rate and grit size and also that of spark out passes on the surface roughness generated have been investigated.

Abstract: A precision 6-degree-of-freedom measurement system has been developed for simultaneous on-line measurements of imprint lithography stage. To successfully accomplish nanometer-scale pattern transfer from mold to resist film on the wafer, two types of positioning methods, static and dynamic, are used in this system. Two laser interferometers, two optical reflection mirrors and special structure on the stage with 3 elastic tracks are employed in this system to detect the positions and rotations of the stage. Through an algorithm, measurements of pitch, yaw and roll motions can be achieved. This system can realize on-line position detecting. Based on adjusting of PZTs, the detecting precision can reach 10nm and ±3 milli-arcsec, respectively. The measuring range can reach 100mm and ±10 arcsec, respectively.