Investigation of Al-doped silicon nitride-based semiconductor and its shrinkage mechanism

Abstract

An Al-doped silicon nitride-based semiconductor is successfully synthesized by the chemical vapor deposition (CVD) technique. Optical, electrical and electronic properties are investigated in detail which reveal that Al-doped α-Si3N4 presents a typical semi-conductive character with a band-gap of 2.65 eV and an electrical conductivity of ∼6.11 × 10−2 S cm−1. Al-doping complex (substitutional accompanied with interstitial Al ions in the (102) plane) in α-Si3N4 lattice and its resulting abnormal crystal growth property are discussed. Experimental and theoretical calculation results indicate that this peculiar Al-doping complex in the (102) plane is responsible for the shrinkage of the band-gap for Al-doped α-Si3N4. The presented results demonstrate that this Al-doped α-Si3N4 may open up many applications opportunities in optics, electronics and photoelectronics fields.