Low temperature fabrication of APCVD a-Si thin film transistors with ion doped layer

The effect of substrate temperature on the electrical and optical properties of AP (atmospheric pressure) chemical vapor deposited (CVD) a-Si films to fabricate low substrate temperature CVD a-Si TFT was investigated. The photosensitivity and hydrogen content of APCVD a-Si film deposited at 380°C are 1.35 × 10 5 and 3.08 at.%, respectively. This film exhibited an Urbach energy of 53 meV and defect density of 5 × 10 15 cm −3. The conductivity and conductivity activation energy for an ion doped a-Si layer with an ion dose of 2.7 × 10 14 cm −2 are 4.6 × 10 −3 S cm −1 and 0.11 eV, respectively. The fabricated APCVD a-Si TFT using a-Si film deposited at 380°C exhibited the field effect mobility of 1 cm 2 V s −1 and threshold voltage of 7.5 V.