TY - JOUR
T1 - Modeling of radial uniformity at a wafer interface in a 2f-CCP for Si O2 etching
AU - Yagisawa, T.
AU - Shimada, T.
AU - Makabe, T.
N1 - Funding Information:
This work was supported in part by a Grant in Aid for the 21st Century Center of Excellence for Optical and Electronic Device Technology for Access Network from the Ministryof Education, Culture, Sports, Science and Technology inJapan.
PY - 2005
Y1 - 2005
N2 - Two-frequency capacitively coupled plasmas (2f-CCP) are commonly used as a powerful tool for etching of metallic and dielectric materials. Functional separation between two sources, by which independent control of high-density plasma production and high-energy ion injection onto a wafer surface can be realized, will be strongly required for a precise control of the plasma etcher. When increasing the size of the wafer and aiming at high productivity, radial uniformity in the characteristics of Si O2 etching will become a more essential issue to be addressed. The predicted radial uniformity at the wafer interface and the functional separation have been examined numerically by using VicAddress [in Advances in Low Temperature RF plasmas, edited by T. Makabe (Elsevier, Amsterdam, 2002)] in a 2f-CCP etcher in C F4 (5%) Ar at 50 mTorr. This etcher was driven at very high frequency (100 MHz) for the production of high-density plasma and at low frequency (1 MHz) for the bias source. The plasma structure and ion velocity distribution at a wafer interface, which have a direct influence on the property of etching, are mainly discussed. Close to the wafer edge, the distortion of the potential intrinsic to the etcher has a greater effect on the ion angular distribution rather than on the ion energy distribution, resulting in a reduction of the radial uniformity of etching.
AB - Two-frequency capacitively coupled plasmas (2f-CCP) are commonly used as a powerful tool for etching of metallic and dielectric materials. Functional separation between two sources, by which independent control of high-density plasma production and high-energy ion injection onto a wafer surface can be realized, will be strongly required for a precise control of the plasma etcher. When increasing the size of the wafer and aiming at high productivity, radial uniformity in the characteristics of Si O2 etching will become a more essential issue to be addressed. The predicted radial uniformity at the wafer interface and the functional separation have been examined numerically by using VicAddress [in Advances in Low Temperature RF plasmas, edited by T. Makabe (Elsevier, Amsterdam, 2002)] in a 2f-CCP etcher in C F4 (5%) Ar at 50 mTorr. This etcher was driven at very high frequency (100 MHz) for the production of high-density plasma and at low frequency (1 MHz) for the bias source. The plasma structure and ion velocity distribution at a wafer interface, which have a direct influence on the property of etching, are mainly discussed. Close to the wafer edge, the distortion of the potential intrinsic to the etcher has a greater effect on the ion angular distribution rather than on the ion energy distribution, resulting in a reduction of the radial uniformity of etching.
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U2 - 10.1116/1.2040447
DO - 10.1116/1.2040447
M3 - Article
AN - SCOPUS:31144476035
VL - 23
SP - 2212
EP - 2217
JO - Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
JF - Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
SN - 1071-1023
IS - 5
ER -