비점수차법을 이용한 간섭계의 정밀 측정 방법
Precise measurement method of interferometer by using the astigmatism methods
- 주제(키워드) 비점수차 , 간섭계 , 2π 모호성 , astigmatism , interferometer , 2π ambiguity
- 발행기관 서강대학교 대학원
- 지도교수 이승엽
- 발행년도 2009
- 학위수여년월 2009. 8
- 학위명 석사
- 학과 일반대학원 기계공학과
- 실제URI http://www.dcollection.net/handler/sogang/000000045442
- 본문언어 한국어
- 저작권 서강대학교의 논문은 저작권에 의해 보호받습니다
초록/요약
An interferometer system enables a precise surface measurement with the accuracy of sub-nanometer and the relatively wide detecting range. However, the surface height change between adjacent pixels should be limited to within one-quarter of the measurement wavelength, which is usually called “2π-Ambiguity”. We propose a new measurement technique to overcome the 2π-Ambiguity problem using both focus error signal(FES) generated by an astigmatic lens and mach zhender interferometer which has 820 Mhz difference between signals and reference light frequencies. This paper achieves the spatial resolution of 2 nm and the height range of 30 μm. The proposed profiler enables the optical measurement of surface profiles with a large height range or the composite materials changing both the amplitude and phase of interference signal the same time.
more