AVS 47th International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP10
The Effects of Substrate Temperature on Self-Aligned Contact Etching Process

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: C.W. Chu, Samsung Electronics, Korea
Authors: C.W. Chu, Samsung Electronics, Korea
J. Kim, Samsung Electronics, Korea
K.-K. Chi, Samsung Electronics, Korea
T.-H. Ahn, Samsung Electronics, Korea
J.-T. Moon, Samsung Electronics, Korea
Correspondent: Click to Email
In this paper we tried to elucidate the behavior of the selectivity of SiO@sub 2@ to underlying Si@sub 3@N@sub 4@ with the wafer surface temperature. The two kinds of specimen, non-patterned and patterned wafer, were etched in Surface Wave Plasma (Sumitomo) reacto which has an electrostatic chuck. The cooling temperature was varied from -20 to +50 in the C@sub 4@F@sub 8@ plasma. As the wafer temperature goes up, the etch-rates of SiO@sub 2@, Si@sub 3@N@sub 4@ and poly-Si of non-patterned wafer increased and the selectivity decreased, and vice versa for the patterned specimen. By increasing temperature, the decrease of etch-rate of SiO@sub 2@, the increase of selectivity of SiO@sub 2@ to Si@sub 3@N@sub 4@, and the increase of profile angle were observed in the case of the patterned specimen. These observations indicate the important role of the photo-resist erosion and sticking coefficient with a wafer temperature. The effect of carbon enrichment induced by photo-resist erosion was identified by comparing photo-resist-patterned samples with hardmask (poly-Si) patterned ones. The other fact was also supported by the polymer deposition with a low bias power etching in that, the thickness of polymer on the side-wall decreases and the thickness of polymer on the bottom increases as the wafer temperature goes up. In summary, there are two main causes in the effects of substrate temperature, and we can find out the difference between the non-patterned sample etching and the patterned sample etching from the viewpoint of surface reaction.