By using Al interlayer to separate Cu and In, but Al is very easy to be oxidized by air. For avoiding that, using In layer can achieve that goal. And using Al interlayer can reduce the roughness of the CIS surface. The other idea is to substitute Al by Sb. In RTA selenzation process, the roughness of the CIS surface by with Sb interlayer is much smoother than using Al interlayer. And the grain with Sb interlayer is more compact (mean grain size is more than 1£gm). The composition test of CIS is measured by EPMA and EDS of TEM. In EPMA measurement, the composition of CIS by using Sb interlayer is more uniform (standard deviation is less than 1 atomic percent), and the composition of CIS by using Al interlayer is less uniform (standard deviation is 1 to 2 atomic percent). In these experiments, the assumption of composition of CIS is Cu/In=1.05, CIS with Al interlayer is Cu/In=1.05, CIS with Sb interlayer is Cu/In=0.90, and the results are 1.05, 1.05, and 0.89. The assumption is very close to the result. In EDS of TEM measurement, the results are the same as the result of paper (composition is different everywhere) and the standard deviation are bigger than 1 atomic percent, but the mean composition is similar to EPMA.