Electrical and Optical Properties of Nitrogen-Incorporated Silicon-Oxide Films by Using Plasma-Enhanced Chemical-Vapor Deposition with Tetramethoxysilane /N2O/NH3 Gas

Nitrogen-incorporated silicon-oxide thin .lms have been deposited by using inductively coupled plasma-enhanced chemical-vapor deposition with tetramethoxysilane (TMOS), N2O, and NH3 gas mixtures. The chemical bonding states and compositions of the deposited .lms are analyzed by Fourier transform infrared (FTIR) spectroscopy and by X-ray photoelectron spectroscopy, and in-situ ellipsometry measurements are performed on the deposited .lms for optical characterization. The eects of the partial pressure ratio of TMOS to N2O and the radio-frequency input power on the properties of the .lm are investigated. Capacitance-voltage measurements are performed in metal-oxide-semiconductor capacitors to obtain the electrical properties of the deposited .lms. As the partial pressure of N2O decreases, the refractive index begins to decrease, reaches a minimum, and then increases again. We attribute the variation of the refractive index to the incorporation of oxygen, carbon, and nitrogen atoms. FTIR absorption bands are observed from about 850 to 1000 cm¡1 and 1120 to 1180 cm¡1, and can be attributed to the formation of a nitrogen-incorporated silicon-oxide .lm. The .xed charge density increases .rst, has a maximum, and decreases with increasing N2O fraction while the interface trap density increases with increasing N2O fraction. KCI Citation Count: 3