| Title |
P-type Capacitance Observed in Nitrogen-doped ZnO |
| Authors |
유현근(Yoo, Hyun-Geun) ; 김세동(Kim, Se-Dong) ; 이동훈(Lee, Dong-Hoon) ; 김정환(Kim, Jung-Hwan) ; 조중열(Jo, Jung-Yol) |
| DOI |
https://doi.org/10.5370/KIEE.2012.61.6.817 |
| Keywords |
ZnO ; MOCVD ; CV characteristics ; TFT ; Nitrogen ; Display |
| Abstract |
We studied p-type capacitance characteristics of ZnO thin-film transistors (TFT's), grown by metal organic chemical vapor deposition (MOCVD). We compared two ZnO TFT's: one grown at 450°C and the other grown at 350°C. ZnO grown at 450°C showed smooth capacitance profile with electron density of 1.5×10^{20}cm^{-3}. In contrast, ZnO grown at 350°C showed a capacitance jump when gate voltage was changed to negative voltages. Current-voltage characteristics measured in the two samples did not show much difference. We explain that the capacitance jump is related to p-type ZnO layer formed at the SiO_2 interface. Current-voltage and capacitance-voltage data support that p-type characteristics are observed only when background electron density is very low. |