Infrared thermal chemical vapor deposition of thin SiN film on InP: Dependence of deposition rate and film characteristics on pressure and gas flux ratio

The dependences of the film deposition rate and the film characteristics on the pressure and the gas flux ratio (NH3/SiH6) are investigated. A thin SiN film is deposited on InP substrate in the very wide pressure range from 1 to 100 Torr and in the very wide gas flux ratio range from 50 to 1300. The film thickness, the refractive index of the films and the capacitance of the MIS diodes are measured. The film surface morphology is observed by microphotography. As a result, it is shown that the deposition rate increases drastically as the pressure increases, that the film surface becomes smooth in the gas flux ratio range from 50 to 500 at 5 Torr, and from 800 to 1300 at 10 Torr, and that the minimum values of the refractive index and the surface state density (Nss) of the film deposited at 10 Torr and flux ratio of 1000 are 2.01 and 2.21×1011 cm-2eV-1, respectively.