1,4-Bis(trimethylsilyl)piperazine-Thermal Properties and Application as CVD Precursor

We report an investigation into 1,4-Bis-N,N-(trimethylsilyl)piperazine (BTMSP) as a novel precursor for the synthesis of silicon carbonitride films by chemical vapor deposition (CVD). The thermal stability, temperature dependence of vapor pressure and thermodynamic constants of the evaporation process of BTMSP were determined by static tensimetry with a glass membrane zero manometer. The transformation of the compound in low-power (25 W) plasma conditions was investigated by optical emission spectroscopy. It was shown that BTMSP undergoes destruction, accompanied by H and CH elimination and CN formation. SiCN(H) films were deposited in a hot-wall plasma-enhanced CVD reactor. The optical properties of the films were studied by spectral ellipsometry (refractive index: 1.5-2.2; absorption coefficient: 0-0.12) and UV-Vis spectroscopy (transmittance: up to 95%; optical bandgap: 1.6-4.9 eV). Information on the aging behavior of the films is also provided. The transformation of the films occurred through water adsorption and the formation of Si-O bonds with the degradation of Si-H, N-H and Si-CHx-Si bonds.