| AVS 66th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Thursday Sessions |
| Session PS+2D+EM+SS+TF-ThA |
| Session: | Plasma-Enhanced Atomic Layer Etching |
| Presenter: | Hojin Kim, TEL Technology Center, America, LLC |
| Authors: | H. Kim, TEL Technology Center, America, LLC Y. Shi, TEL Technology Center, America, LLC Y.-H. Tsai, TEL Technology Center, America, LLC D. Zhang, TEL Technology Center, America, LLC Y. Han, TEL Technology Center, America, LLC K. Taniguchi, TEL Miyagi Limited S. Morikita, TEL Miyagi Limited M. Wang, TEL Technology Center, America, LLC A. Mosden, TEL Technology Center, America, LLC A. Metz, TEL Technology Center, America, LLC P.E. Biolsi, TEL Technology Center, America, LLC |
| Correspondent: | Click to Email |
To understand the selective removal of silicon oxide (SiO2) against silicon nitride (Si3N4) with gaseous reactants for advanced etch process, we have studied the surface modification of both SiO2 and Si3N4 substrates with Ar+ bombardment by using molecular dynamics (MD) simulation. The substrate samples was prepared with and without carbon (C) and hydrogen (H) polymerization to investigate the effect of polymerization on surface modification. C and H atoms were deposited with low ion energy not to disrupt the surface much. After preparation of substrate, Ar+ bombardment with various ion energy (IE) were performed. We obtained a damage depth with a wigner-seitz defect analysis as a function of IE and compared the cases with and without polymerization to check the role of the added polymer layer on surface modification. In pristine Si3N4 and SiO2 case, at IE=25eV, both substrates starts to show the damage with penetration of Ar+ and follows with an exponential raise as the IE increases. Damage depth at Si3N4 is deeper than that at SiO2. In polymerization, simulations show that H is more deposited than C on Si3N4 while on SiO2, C is more deposited than H. no silicon-hydrogen bonds appear on both substrates and in Si3N4, nitrogen-hydrogen bond is dominated while oxygen-carbon bond is popular in SiO2. For damage analysis, in Si3N4 case, CH polymerization helps to lower about 30% in the damage depth with exponential behavior. However, SiO2 case shows the opposite effect of CH polymerization in the damage depth. Formed polymer layer leads to increase the damage depth by comparing with pristine SiO2 and helps more clear exponential behavior as a function of IE. Finally, analyzed results using XPS and/or SIMS from blanket SiO2 and Si3N4 films etched in a Capacitively Coupled Plasma (CCP) chamber are compared with the MD simulation results.