TY - JOUR
T1 - High selectivity in dry etching of silicon nitride over Si using a novel hydrofluorocarbon etch gas in a microwave excited plasma for FinFET
AU - Nakao, Y.
AU - Matsuo, T.
AU - Teramoto, Akinobu
AU - Utsumi, H.
AU - Hashimoto, K.
AU - Kuroda, R.
AU - Shirai, Y.
AU - Sugawa, S.
AU - Ohmi, T.
N1 - Publisher Copyright:
© 2014 by The Electrochemical Society.
PY - 2014
Y1 - 2014
N2 - Increased etch selectivity of SiNx over Si is required for the gate spacer formation in miniaturized MISFETs, especially in the FinFET. In this work, the selectivity of SiNx over Si is evaluated using a novel hydrofluorocarbon etch gas with a microwave excited high-density plasma. By using this novel etchant gas, a higher selectivity of SiNx over Si was obtained compared to CH3F. The etch rate of Si was suppressed due to the deposition of a hydrocarbon film on Si surface without O2 gas. It was found that the selectivity of SiNx over Si near the SiNx sidewall decreased compared that far from the SiNx sidewall. By using flow rates of more than 12 sccm of the novel CxHyFz gas, the gate spacer was formed without Si recess even after the SiNx was overetched for an equivalent thickness of 40 nm.
AB - Increased etch selectivity of SiNx over Si is required for the gate spacer formation in miniaturized MISFETs, especially in the FinFET. In this work, the selectivity of SiNx over Si is evaluated using a novel hydrofluorocarbon etch gas with a microwave excited high-density plasma. By using this novel etchant gas, a higher selectivity of SiNx over Si was obtained compared to CH3F. The etch rate of Si was suppressed due to the deposition of a hydrocarbon film on Si surface without O2 gas. It was found that the selectivity of SiNx over Si near the SiNx sidewall decreased compared that far from the SiNx sidewall. By using flow rates of more than 12 sccm of the novel CxHyFz gas, the gate spacer was formed without Si recess even after the SiNx was overetched for an equivalent thickness of 40 nm.
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U2 - 10.1149/06103.0029ecst
DO - 10.1149/06103.0029ecst
M3 - Conference article
AN - SCOPUS:84925218449
VL - 61
SP - 29
EP - 37
JO - ECS Transactions
JF - ECS Transactions
SN - 1938-5862
IS - 3
T2 - International Symposium on Silicon Compatible Materials, Processes, and Technologies for Advanced Integrated Circuits and Emerging Applications 4 - 225th ECS Meeting
Y2 - 11 May 2014 through 15 May 2014
ER -