Hyun-Ho Doh*, Wonseok Lee, Sangsup Jeong, Changjin Kang, Jootae Moon, Moonyong Lee

Samsung semiconductor R&D center, San #24 Nongseo-Ri, Kiheung-Eup, Yongin-City, Kyungki-Do, Korea
dhh@samsung.co.kr

A fluorocarbon polymer film characteristics prepared by C2F6/CH3F inductively coupled plasma (ICP) was studied using photoelastic modulated fuorier-transform infra-red reflectance absorption spectroscopy (PEM-IRRAS). PEM-IRRAS is a suitable surface analysis tool which can separate each chemical bonding. We investigated the characteristics of the fluorocarbon films prepared as functions of CH3F gas mixing ratio and bias RF power respectively. The other ICP experimental condition was the pressure of 10 mTorr and 2200 W of source RF power.

A C=C stretching, C-Fx stretching, Si-Fx stretching, C-H stretching and bending peaks were investigated on the blank polysilicon/oxide/Si sample with 0 W of bias RF power.

When CH3F gas ratio to C2F6 increased, the oxide etch selectivity to the photoresist mask and to the polysilicon increased, and the fluorocarbon film became more hydrogen-rich and the peak for C=C bonding appeared.

Increasing the bias power with the fixed CH3F 40% gas mixing ratio, C=C bonding, Si-Fx decreased and the polymer film became less fluorine-rich.

The correlation between etch characteristic and the fluorocarbon film properties which was studied by PEM-IRRAS will be discussed.