Depth Profile Analysis of Plasma-cured Multi Layer Resist

Abstract

We investigated that the structural changes in the depth direction of the bottom layer for multi layer process and the effects on improving the resistance against the dry etching process by H2 plasma curing. Diamond like amorphous carbon structure that included sp2 and sp3 carbon cluster was generated near the surface by H2 plasma treatment. The diamond like amorphous carbon was harder than polymer material and had good resistance to the dry etching process in generally. It was cleared that the thickness of the modified layer was approximately 50nm by means of a spectroscopic ellipsometry. Although the thickness of the modified layer was decreased by the dry etching process, the entire region of the modified layer did not disappear after the dry etching process. Therefore, the resistance of the modified layer against the dry etching process maintained and it was confirmed that the modification (hardening process) by H2 plasma treatment had the effect on improving the resistance of the sample against the dry etching process. In addition, it could be expected that H2 plasma treatment had this effect in plural sample structure.