Abstract
N-type junctionless (JL) planar poly-Si thin-film transistors (TFTs), which contain an in situ heavily phosphorous-doped channel with thickness ranging from 8 to 12 nm, were fabricated and characterized. The devices exhibit superior current drive and good control over performance variability. From $C$- $V$ characterization, the ionized dopant concentration in the channel is determined to be around 2 \times \hbox{10}^{19} \ \hbox{cm}-3 and the fixed charge density to be around $-6 \times \hbox{10}^{12} \ \hbox{cm}-2. The negative fixed charge density is probably related to the segregation of phosphorous species at the oxide/channel interface. We also observed a reverse short-channel effect from the relationship between the threshold voltage and the channel length. One mechanism considering enhanced phosphorous segregation is proposed to explain this finding.
Original language | English |
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Article number | 6428639 |
Pages (from-to) | 1142-1148 |
Number of pages | 7 |
Journal | IEEE Transactions on Electron Devices |
Volume | 60 |
Issue number | 3 |
DOIs | |
State | Published - 5 Feb 2013 |
Keywords
- Fixed charges
- junctionless (JL) transistors
- poly-Si
- short-channel effect
- thin-film transistor (TFT)