Abstract The technique inspection surface without touch in the surface has been used widely in the industry and research science. The Optical profiler is the one of tool which can measurement the surface of wafer without touch in the surface .In decade, the engineer and science have been research new metrologic to measurement with less possible uncertainty used white laser in optical profiler. In this paper, we will provide a brief testing surface Silicon oxide (SiO2) .The measurement the test at one location with four of test to solve height of the slope on surface of SiO2. The deviation of the four test height is 274.3 nm. However the operation manual optical profiler measurement show error 3 nm with VSI, The percent error from deviation measurement and manual are

Keywords: accuracy, optical critical dimension metrology, uncertainty analysis