Search

Investigates the vibrational absorption of silicon hydride in amorphous SiO[sub x]:H film based on the charge-transfer model. Examination of absorption profiles on the basis of random-bonding model; Use of Sanderson's electronegativity to study the length of hydride bonds; Details on the peak wave numbers for the four hydrogen-silicon bonding units.

Amorphous SiNx:H films were prepared by rf glow discharge (GD) of SiH4-N2-H2 mixtures at 300 °C using a new decomposition technique. The optical gap Eg increases slowly with the ratio N2/SiH4 up to a critical gap Egc of 2.5–3.0 eV, and then rapidly increases up to 5.3 eV. The spin density Ns from electron spin resonance of Si dangling bonds increases with N2/SiH4 until Eg reaches Egc. Above Egc, Ns rapidly decreases in contrast with that of conventional GD films, but in similarity to pyrolytic films. The slope B in Tauc equation for optical absorption corresponds well with Ns. [ABSTRACT FROM AUTHOR]

Microcrystalline SiNx:H films were prepared by rf glow discharge of SiH4-B2H6-N2-H2 mixtures with the gas volume ratio of B2H6/SiH4=4.5×10-3. The volume fraction of the crystalline phase and the crystallite size decrease with an increase in N content x, and the films were amorphous at x above 0.2. The dark conductivity σd decreases and the optical gap Eg increases with x. The gap-state density is lowest at x near 0.2, where σd∼10-2–10-3/Ω cm (the activation energy is 0.1 eV) and Eg∼1.9 eV. These electrical properties are improved as compared with those for B-doped amorphous SiNx:H. [ABSTRACT FROM AUTHOR]

Investigates the bonding configuration and defects in amorphous SiN[sub x]:H films. Maximum of the slope in the Urbach form of the absorption coefficient; Examination of the random-bonding model including hydrogen atoms.

Polycrystalline silicon (poly-Si) films were prepared on a fused quartz substrate at 700 °C by low-pressure chemical vapor deposition (LPCVD) and plasma-enhanced CVD (PECVD) using the same fabrication system. Poly-Si films with a strong <100> and <110> preferential orientation (P.O.) are obtained by changing the rf power for generating the plasma under the same preparation condition. The surface of the PECVD films with dominant <100> and <110> textures is very smooth in contrast with that of LPCVD films. These textures are maintained after thermal oxidation at 1000 °C, and the degree of P.O. and the grain size increase. [ABSTRACT FROM AUTHOR]