Relationship between bonding characteristics and etch-durability of amorphous carbon layer

Abstract

In the semiconductor industry, amorphous carbon layer (ACL) is widely used as a mask during the etching process. Recent advances in patterning require masks with better etch-durability. To develop such mask, it is essential to understand the relationship between the chemical composition and the etch-durability of the mask. In this work, the relationship between the bonding nature of ACL films and their etch-durability is studied. The bonding characteristics were measured by Fourier transform infrared spectroscopy and the ACL films were deposited under various conditions to observe the change in bonding characteristics. The experimental results show that the ratio between carbon-carbon and carbon-hydrogen bonding is correlated to the etch-durability of ACL film and it is found to be universal under various conditions. Based on this result, an indirect, nondestructive method to determine the etch-durability of the ACL is proposed. (C) 2013 Elsevier B. V. All rights reserved.