IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Manufacturing Science and Technology Monday Sessions
       Session MS-MoP

Paper MS-MoP4
Line Type SAC with Oxide Spacer(LSOS) Adopting Flowfill Oxide for 0.10µm Design Rule and Beyond

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Aspects of Manufacturing Science and Technology Poster Session
Presenter: S.C. Park, Hynix Semiconductor, Inc., Korea
Authors: S.C. Park, Hynix Semiconductor, Inc., Korea
S.D. Lee, Hynix Semiconductor, Inc., Korea
S.T. Ahn, Hynix Semiconductor, Inc., Korea
J.C. Ku, Hynix Semiconductor, Inc., Korea
D.S. Kim, Hynix Semiconductor, Inc., Korea
J.W. Kim, Hynix Semiconductor, Inc., Korea
H.K. Yoon, Hynix Semiconductor, Inc., Korea
Correspondent: Click to Email
In this study, we used Flowfill oxide in the Line-type SAC with Oxide Spacer(LSOS) process, a storage node contact formation technology for DRAM devices. During our LSOS process, a bit-line sidewall was formed after SAC etching, which substantially reduced the aspect ratio of ILD gap-fill process.@footnote 1@ However, for 0.10µm design rule and beyond, even when the LSOS process was applied, small voids were created because conventional High Density Plasma(HDP) oxide was not able to fill the gap between bit-lines. Therefore, we selected Flowfill oxide as a novel InterLayer Dielectric(ILD) material instead of HDP oxide. The key attribute of Flowfill oxide is a unique chemistry of SiH@sub 4@ and H@sub 2@O@sub 2@, which generates a liquid-like intermediate compound that fills very narrow gaps and provides excellent planarity.@footnote 2@ In this experiment, to deposit the Flowfill oxide, TRYKON Planar 200 system was used. A higher Si@sub 3@N@sub 4@ selectivity was obtained when Flowfill oxide was used during the SAC etching, compared to HDP oxide. To find the exact cause of such a high selectivity with Flowfill oxide, X-ray Photoelectron Spectroscopy(XPS) was used to analyze partially etched Flowfill oxide and HDP oxide sample. The XPS analysis showed that a thicker fluorocarbon film was formed on Flowfill oxide and the carbon concentration of the fluorocarbon film was higher on Flowfill oxide. The difference of fluorocarbon film can be due to the presence of hydrogen in Flowfill oxide. In addition, we found that even though Flowfill oxide was annealed for the purpose of densification, nano-pores were created at the bottom of the gap between bit-lines. These nano-pores resulted in a partial stoppage of the SAC etching process, so we had to remove the remaining layer during the sidewall etching. Furthermore, we were able to check the practicality of the LSOS process with Flowfill oxide by fabricating a 256Mb density test vehicle having 0.10µm design rule. @FootnoteText@ @footnote 1@ K.H. Yoon, S.C. Park, et. al.,Symp. on VLSI Tech. Dig., 2001, in press. @footnote 2@ M. Matsuura, et. al., IEDM Tech. Dig., 1994, P.117