Abstract
Vole lllvesnguted the surface roughness charactenstics of the super~polished mirror substrate made by bowl-feed technique. in comparison with the case of fresh-feed technique. Fresh-feed techmque and bowl-feed technique were tried lor substrate surface polishing, and the surface roughne~s was estimated by phase-measunng interferometry. l11e slilface roughness of the substrate after bowl-feed procedure was Improved approxImately three times as fine as that after fresh-feed procedure. and tbe nns roughness of less than $0.5\AA$ and up to $0.3\AA$ at its best was obtained for the bowl-feed procedure. The surface roughness changes by (he bowl-feed technique. compated with tbe fresh-feeclleclmique. were analyzed witb tbe help of both 1 -dimensional roughne,>s profde and rougbness amplItude spect1U1l1 of the polished substrate, whIch ascertained that the final polishing partIcle size of the bowl-feed ptocedure was much smaller than that of the fresh~feed procedure. edure.
Bowl-feed식 연마공정에 의한 초연마 반사경 기판의 표면 거칠기 특성이 전통적인 fresh-feed식 연마공정의 경우와 비교하여 조사하였다. Bowl-feed식 연마기법에 의해 가공된 반사경 기판의 표면 거칠기는 fresh-feed식 연마공정에 비해 약 3배 개선되었으며, 표면 거칠기 RMS값의 경우 $0.5\AA$이하, 최고 $0.3\AA$의 양호한 결과를 얻었다. 또한, 연마된 반사경 기판의 1차원 표면 거칠기 분포도와 표면 거칠기 amplitude spectrum으로부터 fresh-feed 공정에 대한 bowl-feed 연마공정의 기판표면구조 변화상태가 분석되었다.