Abstract
We demonstrate the contact resistance reduction for III-V semiconductor-based electrical and optical devices using the interfacial dipole effect of ultrathin double interlayers in a metal-interlayers-semiconductor (M-I-S) structure. An M-I-S structure blocks metal-induced gap states (MIGS) to a sufficient degree to alleviate Fermi level pinning caused by MIGS, resulting in contact resistance reduction. In addition, the ZnO/TiO2 interlayers of an M-I-S structure induce an interfacial dipole effect that produces Schottky barrier height (ΦB) reduction, which reduces the specific contact resistivity (ρc) of the metal/n-type III-V semiconductor contact. As a result, the Ti/ZnO(0.5 nm)/TiO2(0.5 nm)/n-GaAs metal-double interlayers-semiconductor (M-DI-S) structure achieved a ρc of 2.51 × 10-5 Ω·cm2, which exhibited an ∼42 000× reduction and an ∼40× reduction compared to the Ti/n-GaAs metal-semiconductor (M-S) contact and the Ti/TiO2(0.5 nm)/n-GaAs M-I-S structure, respectively. The interfacial dipole at the ZnO/TiO2 interface was determined to be approximately −0.104 eV, which induced a decrease in the effective work function of Ti and, therefore, reduced ΦB. X-ray photoelectron spectroscopy analysis of the M-DI-S structure also confirmed the existence of the interfacial dipole. On the basis of these results, the M-DI-S structure offers a promising nonalloyed Ohmic contact scheme for the development of III-V semiconductor-based applications.
| Original language | English |
|---|---|
| Pages (from-to) | 35614-35620 |
| Number of pages | 7 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 8 |
| Issue number | 51 |
| DOIs | |
| Publication status | Published - 2016 Dec 28 |
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Keywords
- Fermi level pinning
- gallium arsenide
- interfacial dipole
- Schottky barrier
- specific contact resistivity
ASJC Scopus subject areas
- Materials Science(all)
Cite this
The Effect of Interfacial Dipoles on the Metal-Double Interlayers-Semiconductor Structure and Their Application in Contact Resistivity Reduction. / Kim, Sun Woo; Kim, Seung Hwan; Kim, Gwang Sik; Choi, Changhwan; Choi, Rino; Yu, Hyun-Yong.
In: ACS Applied Materials and Interfaces, Vol. 8, No. 51, 28.12.2016, p. 35614-35620.Research output: Contribution to journal › Article
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TY - JOUR
T1 - The Effect of Interfacial Dipoles on the Metal-Double Interlayers-Semiconductor Structure and Their Application in Contact Resistivity Reduction
AU - Kim, Sun Woo
AU - Kim, Seung Hwan
AU - Kim, Gwang Sik
AU - Choi, Changhwan
AU - Choi, Rino
AU - Yu, Hyun-Yong
PY - 2016/12/28
Y1 - 2016/12/28
N2 - We demonstrate the contact resistance reduction for III-V semiconductor-based electrical and optical devices using the interfacial dipole effect of ultrathin double interlayers in a metal-interlayers-semiconductor (M-I-S) structure. An M-I-S structure blocks metal-induced gap states (MIGS) to a sufficient degree to alleviate Fermi level pinning caused by MIGS, resulting in contact resistance reduction. In addition, the ZnO/TiO2 interlayers of an M-I-S structure induce an interfacial dipole effect that produces Schottky barrier height (ΦB) reduction, which reduces the specific contact resistivity (ρc) of the metal/n-type III-V semiconductor contact. As a result, the Ti/ZnO(0.5 nm)/TiO2(0.5 nm)/n-GaAs metal-double interlayers-semiconductor (M-DI-S) structure achieved a ρc of 2.51 × 10-5 Ω·cm2, which exhibited an ∼42 000× reduction and an ∼40× reduction compared to the Ti/n-GaAs metal-semiconductor (M-S) contact and the Ti/TiO2(0.5 nm)/n-GaAs M-I-S structure, respectively. The interfacial dipole at the ZnO/TiO2 interface was determined to be approximately −0.104 eV, which induced a decrease in the effective work function of Ti and, therefore, reduced ΦB. X-ray photoelectron spectroscopy analysis of the M-DI-S structure also confirmed the existence of the interfacial dipole. On the basis of these results, the M-DI-S structure offers a promising nonalloyed Ohmic contact scheme for the development of III-V semiconductor-based applications.
AB - We demonstrate the contact resistance reduction for III-V semiconductor-based electrical and optical devices using the interfacial dipole effect of ultrathin double interlayers in a metal-interlayers-semiconductor (M-I-S) structure. An M-I-S structure blocks metal-induced gap states (MIGS) to a sufficient degree to alleviate Fermi level pinning caused by MIGS, resulting in contact resistance reduction. In addition, the ZnO/TiO2 interlayers of an M-I-S structure induce an interfacial dipole effect that produces Schottky barrier height (ΦB) reduction, which reduces the specific contact resistivity (ρc) of the metal/n-type III-V semiconductor contact. As a result, the Ti/ZnO(0.5 nm)/TiO2(0.5 nm)/n-GaAs metal-double interlayers-semiconductor (M-DI-S) structure achieved a ρc of 2.51 × 10-5 Ω·cm2, which exhibited an ∼42 000× reduction and an ∼40× reduction compared to the Ti/n-GaAs metal-semiconductor (M-S) contact and the Ti/TiO2(0.5 nm)/n-GaAs M-I-S structure, respectively. The interfacial dipole at the ZnO/TiO2 interface was determined to be approximately −0.104 eV, which induced a decrease in the effective work function of Ti and, therefore, reduced ΦB. X-ray photoelectron spectroscopy analysis of the M-DI-S structure also confirmed the existence of the interfacial dipole. On the basis of these results, the M-DI-S structure offers a promising nonalloyed Ohmic contact scheme for the development of III-V semiconductor-based applications.
KW - Fermi level pinning
KW - gallium arsenide
KW - interfacial dipole
KW - Schottky barrier
KW - specific contact resistivity
UR - http://www.scopus.com/inward/record.url?scp=85008214362&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85008214362&partnerID=8YFLogxK
U2 - 10.1021/acsami.6b10376
DO - 10.1021/acsami.6b10376
M3 - Article
AN - SCOPUS:85008214362
VL - 8
SP - 35614
EP - 35620
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 51
ER -