Interior surface roughness of ICF micro-shells with phase shift interference technique

Phase-shifting interference(PSI) is an important method in surface roughness measurement. In this paper, on the basis of analyzing phase distribution of micro-shell interface, the measuring principle of interior surface roughness of micro-shells is discussed. Inner surface images of PS and PAMS micro-shells were obtained with PSI method. The results are consistent with the measured results by atomic force microscope. The measurement error is analyzed by studying the influence of thickness fluctuation of micro-shell and outer surface roughness of micro-shell on measured results of SiC and crystal Si surface roughness. The experimental result shows that the measuring uncertainty is under 0.4 nm for micro-shells with 30 nm outer surface roughness and 9 μm thickness.