Influence of Phosphorus Doping in the Active Layer with Deposition Time and Gas Flow Rate in a-Si:H Thin Film Transistor

Abstract

Influence of phosphorus doping in the a-Si:H layer with various deposition time and phosphine gas flow rate in hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) has been investigated. The a-SiN:H layer, the phosphorus doped a-Si:H layer and the n⁺ a-Si:H layer were deposited by plasma enhanced chemical vapor deposition (PECVD) using SiH₄, PH₃, Ar, H₂ and NH₃ gases. Proper phosphorus doping in the a-Si:H layer affected the channel of the a-Si:H TFT and improved the characteristics. Also, the field effect mobility was increased from 0.22 to 0.61 cm²/V·s. The characteristics of phosphorus doping in the a-Si:H TFT were investigated and compared with the conventional a-Si:H TFT.

Keywords:

• phosphorus doping
• channel
• a-Si:H TFT
• the field effect mobility

Acknowledgment

This work was supported by the Regional Innovation Center program (ADMRC) of the Ministry of Knowledge Economy, Republic of Korea.