Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5789173 | Science Bulletin | 2015 | 6 Pages |
Abstract
SiO2/Si substrate has been widely used to support two-dimensional (2-D) crystal flakes grown by chemical vapor deposition or prepared by micromechanical cleavage. The visibility of 2-D flakes is very sensitive to the thickness of the SiO2 layer (hSiO2), which can not be determined precisely after the deposit of 2-D flakes. Here, we demonstrated a simple, fast and nondestructive technique to precisely determine hSiO2 of SiO2 films on Si substrate only by optical contrast measurement with a typical micro-Raman confocal system. Because of its small lateral resolution down to the micrometer scale, this technique can be used to access hSiO2 on SiO2/Si substrate that has been partially covered by 2-D crystal flakes, and then further determine the layer number of the 2-D crystal flakes. This technique can be extended to other dielectric multilayer substrates and the layer-number determination of 2-D crystal flakes on those substrates.
Related Topics
Physical Sciences and Engineering
Chemistry
Chemistry (General)
Authors
Yan Lu, Xiao-Li Li, Xin Zhang, Jiang-Bin Wu, Ping-Heng Tan,