New nano-contouring measurement techniques for a nano-stage

Among the most commonly used contouring measurement methods, no measuring techniques have been available with nanometer resolution except for the grating encoder measurement system. Although the grating encoder measurement system can reach the resolution of nanometers for nano-contouring, its resolution and accuracy of measurement are limited by the manufacturing accuracy of the size of the grating etching, the size of the light-spot and the pitch of the grating. When the contouring radius is less then the pitch of the grating, the grating encoder system does not work. So, no measuring instrument could simultaneously measure the nano-stage contouring error. In this paper, three new nano-contouring measurement techniques for a nano-stage have been successfully developed by employing laser interferometers, corner cubes and some developed fixture. By specified light path arrangements, three different setting-ups are described in this paper. The measuring resolution of these techniques is 10 nm. Contouring tests with a very small radius were carried out. A 500 nm radius contouring test result was given. Since the techniques are simple, it is very easy to set up and to carry out the tests, compared to other systems. Also, the setting-up error can be ignored when the contouring radius is small. A Heidenhain measuring system was employed to verify these three new techniques. Good verification results were obtained to prove these systems.