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 Tuesday Sessions
       Session MS-TuA

Paper MS-TuA2
Characterization of Pattern Transfer from Litho to Etch Using Scatterometry

Tuesday, October 30, 2001, 2:20 pm, Room 131

Session: In Line and In Situ Process Control
Presenter: T.G. Dziura, KLA-Tencor
Authors: T.G. Dziura, KLA-Tencor
U. Whitney, KLA-Tencor
A. Levy, KLA-Tencor
G.P. Kota, Lam Research
G. Peng, Lam Research
R.A. Gottscho, Lam Research
Correspondent: Click to Email
Gate pattern transfer from the lithography after-develop-inspect (ADI) step to post-gate-etch clean was characterized with spectroscopic CD (SCD) measurements on a KLA-Tencor F5-SCD metrology platform. Data were collected on resist-BARC-a-Si gate-gate oxide-Si grating structures at ADI, post-BARC-etch, post-gate-etch, and after-clean-inspect (ACI). Three different gate etch processes were applied using a Lam Research TCP@super ®@ 9400DFM etcher to produce varying sidewall profiles. Measurements were made on grating targets with nominal CD ranging from 75 - 160 nm, and line/space ratios 1:1, 1:3, and 1:5. Both wafer map data and dynamic short-term repeatability data were collected. The profiles obtained were compared to cross-sectional SEM (XSEM) measurements. The CD bias between litho, BARC etch, and gate etch was measured for different nominal CDs and line-to-space ratios. The results indicate that SCD provides enhanced information for optimizing etch processes. Wafer maps of profile parameters can be measured at different stages of the process and correlation coefficients calculated between selected pairs of parameters provide insight into the pattern transfer process. The significantly increased resolution of SCD measurements enables more accurate and detailed process models.