Abstract
The mechanisms of p-to-n conversion and vice versa in unipolar graphene field-effect transistors (GFETs) were systematically studied using Raman spectroscopy. Unipolar p-type GFETs are achieved by decorating the graphene surface with a thin layer of titanium (Ti) film, resulting in a Raman D peak. The D peak is observed to recover by annealing the GFET in nitrogen ambient followed by silicon nitride (Si{sub 3}N{sub 4}) deposition, suggesting that the Ti adatoms are being partially removed. Furthermore, unipolar n-type GFETs are obtained after the passivation on p-type GFETs. The threshold voltage of the n-type GFET is dependent on the thickness of the Si{sub 3}N{sub 4} layer, which increases as the thickness decreases. A comparison between the Si{sub 3}N{sub 4} and SiO{sub 2} passivation layers shows that SiO{sub 2} passivation does not convert the GFET into n-type graphene, which identifies the significance of ammonia (NH{sub 3}) for the formation of the n-type GFETs. This study provides an insight into the mechanism of controlling the conduction behavior of unipolar GFETs. (paper)
Yap, Ray Chin Chong;
Li, Hong;
Chow, Wai Leong;
Lu, Cong Xiang;
Tay, Beng Kang;
Teo, Edwin Hang Tong, E-mail: ebktay@ntu.edu.sg
[1]
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)
Citation Formats
Yap, Ray Chin Chong, Li, Hong, Chow, Wai Leong, Lu, Cong Xiang, Tay, Beng Kang, and Teo, Edwin Hang Tong, E-mail: ebktay@ntu.edu.sg.
Identifying the mechanisms of p-to-n conversion in unipolar graphene field-effect transistors.
United Kingdom: N. p.,
2013.
Web.
doi:10.1088/0957-4484/24/19/195202.
Yap, Ray Chin Chong, Li, Hong, Chow, Wai Leong, Lu, Cong Xiang, Tay, Beng Kang, & Teo, Edwin Hang Tong, E-mail: ebktay@ntu.edu.sg.
Identifying the mechanisms of p-to-n conversion in unipolar graphene field-effect transistors.
United Kingdom.
https://doi.org/10.1088/0957-4484/24/19/195202
Yap, Ray Chin Chong, Li, Hong, Chow, Wai Leong, Lu, Cong Xiang, Tay, Beng Kang, and Teo, Edwin Hang Tong, E-mail: ebktay@ntu.edu.sg.
2013.
"Identifying the mechanisms of p-to-n conversion in unipolar graphene field-effect transistors."
United Kingdom.
https://doi.org/10.1088/0957-4484/24/19/195202.
@misc{etde_22114738,
title = {Identifying the mechanisms of p-to-n conversion in unipolar graphene field-effect transistors}
author = {Yap, Ray Chin Chong, Li, Hong, Chow, Wai Leong, Lu, Cong Xiang, Tay, Beng Kang, and Teo, Edwin Hang Tong, E-mail: ebktay@ntu.edu.sg}
abstractNote = {The mechanisms of p-to-n conversion and vice versa in unipolar graphene field-effect transistors (GFETs) were systematically studied using Raman spectroscopy. Unipolar p-type GFETs are achieved by decorating the graphene surface with a thin layer of titanium (Ti) film, resulting in a Raman D peak. The D peak is observed to recover by annealing the GFET in nitrogen ambient followed by silicon nitride (Si{sub 3}N{sub 4}) deposition, suggesting that the Ti adatoms are being partially removed. Furthermore, unipolar n-type GFETs are obtained after the passivation on p-type GFETs. The threshold voltage of the n-type GFET is dependent on the thickness of the Si{sub 3}N{sub 4} layer, which increases as the thickness decreases. A comparison between the Si{sub 3}N{sub 4} and SiO{sub 2} passivation layers shows that SiO{sub 2} passivation does not convert the GFET into n-type graphene, which identifies the significance of ammonia (NH{sub 3}) for the formation of the n-type GFETs. This study provides an insight into the mechanism of controlling the conduction behavior of unipolar GFETs. (paper)}
doi = {10.1088/0957-4484/24/19/195202}
journal = []
issue = {19}
volume = {24}
journal type = {AC}
place = {United Kingdom}
year = {2013}
month = {May}
}
title = {Identifying the mechanisms of p-to-n conversion in unipolar graphene field-effect transistors}
author = {Yap, Ray Chin Chong, Li, Hong, Chow, Wai Leong, Lu, Cong Xiang, Tay, Beng Kang, and Teo, Edwin Hang Tong, E-mail: ebktay@ntu.edu.sg}
abstractNote = {The mechanisms of p-to-n conversion and vice versa in unipolar graphene field-effect transistors (GFETs) were systematically studied using Raman spectroscopy. Unipolar p-type GFETs are achieved by decorating the graphene surface with a thin layer of titanium (Ti) film, resulting in a Raman D peak. The D peak is observed to recover by annealing the GFET in nitrogen ambient followed by silicon nitride (Si{sub 3}N{sub 4}) deposition, suggesting that the Ti adatoms are being partially removed. Furthermore, unipolar n-type GFETs are obtained after the passivation on p-type GFETs. The threshold voltage of the n-type GFET is dependent on the thickness of the Si{sub 3}N{sub 4} layer, which increases as the thickness decreases. A comparison between the Si{sub 3}N{sub 4} and SiO{sub 2} passivation layers shows that SiO{sub 2} passivation does not convert the GFET into n-type graphene, which identifies the significance of ammonia (NH{sub 3}) for the formation of the n-type GFETs. This study provides an insight into the mechanism of controlling the conduction behavior of unipolar GFETs. (paper)}
doi = {10.1088/0957-4484/24/19/195202}
journal = []
issue = {19}
volume = {24}
journal type = {AC}
place = {United Kingdom}
year = {2013}
month = {May}
}