Nitrogen doped high selectivity amorphous carbon film for high aspect ratio etch process

Abstract

Nitrogen doped high selectivity amorphous carbon layer (NHS-ACL) was carried in this paper. These experiments showed improved thickness and critical dimension uniformity of 50 % and 54 % respectively and relative selectivity by 10 % in amorphous carbon layer used in hardmasks in semiconductor applications. The incorporation of nitrogen increased the extinction coefficient from 0.402 to 0.503, indicating a reduction in hydrogen content within the film and an enhancement in the hexagonal clustering of carbon atoms. Compressive stress increased from +61 to -120 MPa also shows increase in sp³ bonding in the observed films. These results suggest that NHS-ACL has the potential to be applied in the current and future vertical NAND and dynamic random access memory devices without requiring additional costs, such as retrofitting existing equipment or investing in new facilities for mass production.