AVS 46th International Symposium
    Plasma Science and Technology Division Monday Sessions
       Session PS-MoP

Paper PS-MoP19
The Study on The Method of Plasma-Generated-Polymer Attachment to PR Side Wall for Forming Smaller Contact Hole

Monday, October 25, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: K.I. Seo, Samsung Electronic Co.Ltd., Korea
Authors: K.I. Seo, Samsung Electronic Co.Ltd., Korea
J.S. Hwang, Samsung Electronic Co.Ltd., Korea
U.I. Chung, Samsung Electronic Co.Ltd., Korea
K.W. Kang, Samsung Electronic Co.Ltd., Korea
M.-Y. Lee, Samsung Electronic Co.Ltd., Korea
Correspondent: Click to Email
Resent PR ( Photo Resist ) patterning limit by KrF Deep UV ( Ultra Violet ) source is about 0.25~0.27µmm for contact pattern and 0.20~0.22µmm for line & space pattern. For patterning more small pattern size, line & space, new light sources such as ArF, X-ray, E-beam are being tested. But they are not adapted in mass fabrication yet. In this experiment, in order to overcome the patterning limit of photo process, we developed polymer attachment process to PR side wall for forming 0.15µmm size small contact. We tried to attach a uniform layer of polymer to PR side wall by generating various polymers in various gas plasmas such as CF@sub 4@/CHF@sub 3@/Ar, He/HBr, Cl@sub 2@/HBr. We found that C-Cl@sub x@-Br@sub y@ polymer, which has masking ability in the oxide etch process, was attached to PR side wall effectively in Cl@sub 2@/HBr gas plasma of the RIE ( Reactive Ion Etching ) type etcher which had a relatively high process pressure and a low density plasma. Based on the XPS ( X-ray Photon Spectroscopy ) result, the shape of the polymer attached PR, the dependency of the amount of the attached polymer on the contact size and the fact that polymer attachment process required PR loss, we proposed the mechanism of the polymer attachment process. It was observed the oxide etch rate was enhanced about 30% in contact hole size of 0.30µmm, and RIE-Lag was reduced in contact size range of 0.25~0.50µmm after the polymer attachment process, which needs further studies. We applied polymer attachment process to a real MDL ( Merged DRAM with Logic ) device, and obtained contact size of 0.15µmm by SEM ( Scanning Electron Microscopy ) measurement which was smaller than the contact size of normal process by approximately 50 nm as well as good size uniformity ( @<=@ 20 nm ), good particle ( @<=@ 10 ea in entire wafer ), uniform contact resistance in the range of 4800~5700@Ohm@/Cnt, and proper yield data.