Thermal stability of WSix and W ohmic contacts on GaN

X. A. Cao; S. J. Pearton; S. M. Donovan; C. R. Abernathy; F. Ren; J. C. Zolper; M. W. Cole; A. Zeitouny; M. Eizenberg; R. J. Shul; A. G. Baca

doi:10.1016/S0921-5107(98)00351-1

Thermal stability of WSi_x and W ohmic contacts on GaN

X. A. Cao^*, S. J. Pearton, S. M. Donovan, C. R. Abernathy, F. Ren, J. C. Zolper, M. W. Cole, A. Zeitouny, M. Eizenberg, R. J. Shul, A. G. Baca

^*Corresponding author for this work

Research output: Contribution to journal › Conference article › peer-review

3 Scopus citations

Abstract

We have sputter-deposited 500-1200 angstrom thick WSi_0.45 and W metallization onto both n⁺ GaN (n = 10¹⁹ cm^-3) doped either during MOCVD growth or by direct Si⁺ ion implantation (5 × 10¹⁵ cm^-2, 100 keV) activated by RTA at 1400°C for 10 s and p⁺ (N_A = 10¹⁸ cm^-3) GaN. In the n-type epi samples R_c values of 10^-4 Ω cm^-2 were obtained and were stable to approx. 1000°C. The annealing treatments up to 600°C had little effect on the WSi_x/GaN interface, but the β-W₂N phase formed between 700-800°C, concomitant with a strong reduction (approximately a factor of 2) in near-surface crystalline defects in the GaN. Spiking of the metallization down the threading and misfit dislocations was observed at 800°C, extending > 5000 angstrom in some cases. This can create junction shorting in bipolar or thyristor devices. R_c values of approx. 10^MIN6 Ω cm^-2 were obtained on the implanted samples for 950°C annealing, with values of approx. 10^-5 Ω cm^-2 after 1050°C anneals. On p-GaN, the contacts are essentially leaky Schottky diodes at 25°C, but became ohmic at ≥ 250°C, with R_c in the 10^-2 Ω cm^-2 range. The W-based metallization is much more thermally stable than the more common Ni/Au.

Original language	English
Pages (from-to)	362-365
Number of pages	4
Journal	Materials Science and Engineering B: Solid-State Materials for Advanced Technology
Volume	59
Issue number	1-3
DOIs	https://doi.org/10.1016/S0921-5107(98)00351-1
State	Published - 6 May 1999
Externally published	Yes
Event	Proceedings of the 1998 Symposium L: on Nitrides and Related Wide Band Gap Materials (E-MRS Meeting) - Strasbourg Duration: 16 Jun 1998 → 19 Jun 1998

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@article{2bb392247d3b4c50ad00f2f592e8435a,

title = "Thermal stability of WSix and W ohmic contacts on GaN",

abstract = "We have sputter-deposited 500-1200 angstrom thick WSi0.45 and W metallization onto both n+ GaN (n = 1019 cm-3) doped either during MOCVD growth or by direct Si+ ion implantation (5 × 1015 cm-2, 100 keV) activated by RTA at 1400°C for 10 s and p+ (NA = 1018 cm-3) GaN. In the n-type epi samples Rc values of 10-4 Ω cm-2 were obtained and were stable to approx. 1000°C. The annealing treatments up to 600°C had little effect on the WSix/GaN interface, but the β-W2N phase formed between 700-800°C, concomitant with a strong reduction (approximately a factor of 2) in near-surface crystalline defects in the GaN. Spiking of the metallization down the threading and misfit dislocations was observed at 800°C, extending > 5000 angstrom in some cases. This can create junction shorting in bipolar or thyristor devices. Rc values of approx. 10MIN6 Ω cm-2 were obtained on the implanted samples for 950°C annealing, with values of approx. 10-5 Ω cm-2 after 1050°C anneals. On p-GaN, the contacts are essentially leaky Schottky diodes at 25°C, but became ohmic at ≥ 250°C, with Rc in the 10-2 Ω cm-2 range. The W-based metallization is much more thermally stable than the more common Ni/Au.",

author = "Cao, {X. A.} and Pearton, {S. J.} and Donovan, {S. M.} and Abernathy, {C. R.} and F. Ren and Zolper, {J. C.} and Cole, {M. W.} and A. Zeitouny and M. Eizenberg and Shul, {R. J.} and Baca, {A. G.}",

note = "Funding Information: The work at UF is partially supported by a DARPA/EPRI grant (E.R. Brown/J. Melcher). Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed–Martin company for the US Department of Energy under contract No. DEAC04-94AL85000.; Proceedings of the 1998 Symposium L: on Nitrides and Related Wide Band Gap Materials (E-MRS Meeting) ; Conference date: 16-06-1998 Through 19-06-1998",

year = "1999",

month = may,

day = "6",

doi = "10.1016/S0921-5107(98)00351-1",

language = "英语",

volume = "59",

pages = "362--365",

journal = "Materials Science and Engineering B: Solid-State Materials for Advanced Technology",

issn = "0921-5107",

publisher = "Elsevier Ltd.",

number = "1-3",

}

TY - JOUR

T1 - Thermal stability of WSix and W ohmic contacts on GaN

AU - Cao, X. A.

AU - Pearton, S. J.

AU - Donovan, S. M.

AU - Abernathy, C. R.

AU - Ren, F.

AU - Zolper, J. C.

AU - Cole, M. W.

AU - Zeitouny, A.

AU - Eizenberg, M.

AU - Shul, R. J.

AU - Baca, A. G.

N1 - Funding Information: The work at UF is partially supported by a DARPA/EPRI grant (E.R. Brown/J. Melcher). Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed–Martin company for the US Department of Energy under contract No. DEAC04-94AL85000.

PY - 1999/5/6

Y1 - 1999/5/6

N2 - We have sputter-deposited 500-1200 angstrom thick WSi0.45 and W metallization onto both n+ GaN (n = 1019 cm-3) doped either during MOCVD growth or by direct Si+ ion implantation (5 × 1015 cm-2, 100 keV) activated by RTA at 1400°C for 10 s and p+ (NA = 1018 cm-3) GaN. In the n-type epi samples Rc values of 10-4 Ω cm-2 were obtained and were stable to approx. 1000°C. The annealing treatments up to 600°C had little effect on the WSix/GaN interface, but the β-W2N phase formed between 700-800°C, concomitant with a strong reduction (approximately a factor of 2) in near-surface crystalline defects in the GaN. Spiking of the metallization down the threading and misfit dislocations was observed at 800°C, extending > 5000 angstrom in some cases. This can create junction shorting in bipolar or thyristor devices. Rc values of approx. 10MIN6 Ω cm-2 were obtained on the implanted samples for 950°C annealing, with values of approx. 10-5 Ω cm-2 after 1050°C anneals. On p-GaN, the contacts are essentially leaky Schottky diodes at 25°C, but became ohmic at ≥ 250°C, with Rc in the 10-2 Ω cm-2 range. The W-based metallization is much more thermally stable than the more common Ni/Au.

AB - We have sputter-deposited 500-1200 angstrom thick WSi0.45 and W metallization onto both n+ GaN (n = 1019 cm-3) doped either during MOCVD growth or by direct Si+ ion implantation (5 × 1015 cm-2, 100 keV) activated by RTA at 1400°C for 10 s and p+ (NA = 1018 cm-3) GaN. In the n-type epi samples Rc values of 10-4 Ω cm-2 were obtained and were stable to approx. 1000°C. The annealing treatments up to 600°C had little effect on the WSix/GaN interface, but the β-W2N phase formed between 700-800°C, concomitant with a strong reduction (approximately a factor of 2) in near-surface crystalline defects in the GaN. Spiking of the metallization down the threading and misfit dislocations was observed at 800°C, extending > 5000 angstrom in some cases. This can create junction shorting in bipolar or thyristor devices. Rc values of approx. 10MIN6 Ω cm-2 were obtained on the implanted samples for 950°C annealing, with values of approx. 10-5 Ω cm-2 after 1050°C anneals. On p-GaN, the contacts are essentially leaky Schottky diodes at 25°C, but became ohmic at ≥ 250°C, with Rc in the 10-2 Ω cm-2 range. The W-based metallization is much more thermally stable than the more common Ni/Au.

UR - http://www.scopus.com/inward/record.url?scp=0033528901&partnerID=8YFLogxK

U2 - 10.1016/S0921-5107(98)00351-1

DO - 10.1016/S0921-5107(98)00351-1

M3 - 会议文章

AN - SCOPUS:0033528901

SN - 0921-5107

VL - 59

SP - 362

EP - 365

JO - Materials Science and Engineering B: Solid-State Materials for Advanced Technology

JF - Materials Science and Engineering B: Solid-State Materials for Advanced Technology

IS - 1-3

T2 - Proceedings of the 1998 Symposium L: on Nitrides and Related Wide Band Gap Materials (E-MRS Meeting)

Y2 - 16 June 1998 through 19 June 1998

ER -

Thermal stability of WSi_x and W ohmic contacts on GaN

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