Selective area laser-assisted doping of SiC thin films and blue light electroluminescence

Abstract

Laser-assisted doping combined with annealing technique is used in selective areas to form a p-n junction on a SiC thin film grown by the pulsed laser deposition on a Si substrate at a temperature of 800 °C. This approach in an aluminum chloride solution and a phosphoric solution has resulted in p-SiC/n-Si and n-SiC/p-Si hetero-structures, respectively. Further, a functional in-plane p-n junction is realized side-by-side on the post-deposited SiC thin film. I-V characteristics by two probe technique showed the p-n diode characteristics. Blue light (400 nm) electroluminescence from the p-n junction on SiC thin film was observed in the forward biased condition. Further, an improvement in the I-V reverse characteristics was observed by illuminating the p-n SiC thin film with green/blue light.

Simultaneous laser doping and annealing to form lateral p–n junction diode structure on silicon carbide films

“…Similarly, phosphorous doping was carried out in a phosphoric solution (85% H 3 PO 4 ) to obtain n-type SiC thin film. The level of doping solutions was maintained 2 mm above the SiC thin film to avoid splashing 11, 12 . Lateral (side-by-side) p–n SiC diode formation was demonstrated, as presented schematically in Figure 1(c).…”

“…As presented in Figure 5, based on the I–V characteristics, the cut-in voltage values were ≈2.8 V. The value of cut-in voltages was in agreement with the values, ranging from 2.4 V to 2.8 V reported elsewhere 14 . Based on the secondary ion mass spectroscopy (SIMS) (Physical Electronics, Trift V nano TOF) analysis, the depth of doping was ≈100 nm and the intrinsic SiC layer thickness was estimated to be around 70 nm reported elsewhere 12 . The intrinsic SiC resistance was estimated to be 0.7 × 10 9 Ω, whereas the p-SiC and n-SiC resistance is estimated to be between 1 × 10 3 and 4 × 10 3 .…”