Dependence of electrical properties on work functions of metals contacting to p-type GaN

Koide, Yasuo; Ishikawa, H.; Kobayashi, Shoichi; Yamasaki, S.; Nagai, S.; Umezaki, J.; Koike, Masayoshi; Murakami, Masanori

doi:10.1016/s0169-4332(97)80110-9

Cited by 35 publications

(18 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Koide et al also reported a slope of Ϫ0.6 for p-GaN samples treated with a buffered hydrofluoric acid ͑HF͒ solution prior to metal deposition, with the surface-barrier height being calculated from I-V measurements. 46 Our results are in general agreement with these previous studies.…”

Section: Discussionsupporting

confidence: 94%

X-ray photoemission determination of the Schottky barrier height of metal contacts to n–GaN and p–GaN

Rickert

Ellis

Kim

et al. 2002

Journal of Applied Physics

106

View full text Add to dashboard Cite

Synchrotron radiation-based x-ray photoemission spectroscopy was used to study the surface Fermi level position within the band gap for thin metal overlayers of Au, Al, Ni, Ti, Pt, and Pd on n-GaN and p-GaN. Nonequilibrium effects were taken into account by measuring the Fermi edge of the metal overlayer. There are two different behaviors observed for the six metals studied. For Au, Ti, and Pt, the surface Fermi level lies about 0.5-eV higher in the gap for n-type than for p-type GaN. For Ni, Al, and Pd, the surface Fermi level position is independent of doping, but varies from one metal to the other. Results for Ni, Pd, and Al fit a modified Schottky-Mott theory, while Au, Ti, and Pt demonstrate a more complex behavior. Atomic force microscopy was used along with photoemission to investigate the growth mode of each metal on the GaN surface.

show abstract

Section: Discussionsupporting

confidence: 94%

X-ray photoemission determination of the Schottky barrier height of metal contacts to n–GaN and p–GaN

Rickert

Ellis

Kim

et al. 2002

Journal of Applied Physics

106

View full text Add to dashboard Cite

show abstract

“…Current density-voltage (J-V) characteristics of Ni contact to p-ZnSe [7]. ing to our measurement [14,15]. However, ohmic contacts with U C less than 10 4 :-cm 2 are necessary for LDs, requiring the development of an ohmic contacts with a U C three orders of magnitude lower.…”

Section: Ohmic Contact Materials For P-type Gansupporting

confidence: 54%

Ohmic contacts to p-ZnSe and p-GaN wide-gap semiconductors

Koide¹,

Murakami²

1999

Electron. Comm. Jpn. Pt. II

Self Cite

View full text Add to dashboard Cite

Since the Schottky barrier height at the metal/p‐ZnSe and p‐GaN interfaces is very high, and heavy p‐type doping is difficult, it is extremely difficult to obtain low‐resistance ohmic contact material for p‐ZnSe and p‐GaN. However, a key to the development of low‐resistance ohmic contact material is to find an element that forms an intermediate semiconductor layer to reduce the Schottky barrier or to increase the doping concentration. © 1999 Scripta Technica, Electron Comm Jpn Pt 2, 82(10): 43–47, 1999

show abstract

“…On the other hand, the choice of a metal as contact for n-type as well as for p-type GaN is facilitated because indications exist that the barrier height depends on the metal work function. [3][4][5][6][7][8][9][10] The lack of Fermi level pinning at the metal/semiconductor interface is predicted by the ionic nature of GaN. 11 However, the dependence of the barrier height on the metal work function does not follow a linear relation of unity slope as predicted by the Schottky model, 12 and interfacial reactions between the metal and the GaN substrate further affect this relationship.…”

Section: Introductionmentioning

confidence: 99%

“…15,21 A GaN metal-semiconductor field effect transistor ͑MESFET͒ with Au/Pt as Schottky gate is reported to withstand heating in nitrogen at 400°C for 1000 h. 22 Other authors, though, report the degradation of Pt diodes after annealing at 400°C for 1 h. 19 Low-resistance, ohmic contacts to p-type GaN are achieved by using metals with a high work function, 8 and indeed, Pt or Pd yield a lower value of the total resistance compared to other metals. [7][8][9][10] Platinum is not stable with GaN. 23 The reaction at the interface between a Pt film and a GaN substrate is poorly investigated.…”

Section: Introductionmentioning

confidence: 99%

Thermal reaction of Pt film with 〈110〉 GaN epilayer

Gasser

Kolawa

Nicolet

1999

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

Backscattering spectrometry, x-ray diffractometry, and scanning electron microscopy have been used to study the reaction of a thin Pt film with an epilayer of ͗110͘ GaN on ͗110͘ sapphire upon annealing at 450, 550, 650, 750, and 800°C for 30 min. A Ga concentration of 2 at. % is detected by MeV 4 He ϩϩ backscattering spectrometry in the Pt layer at 550°C. By x-ray diffraction, structural changes are observed already at 450°C. At 650°C, textured Ga 2 Pt appears as reaction product. The surface morphology exhibits instabilities by the formation of blisters at 650°C and voids at 800°C.

show abstract

Dependence of electrical properties on work functions of metals contacting to p-type GaN

Cited by 35 publications

References 23 publications

X-ray photoemission determination of the Schottky barrier height of metal contacts to n–GaN and p–GaN

X-ray photoemission determination of the Schottky barrier height of metal contacts to n–GaN and p–GaN

Ohmic contacts to p-ZnSe and p-GaN wide-gap semiconductors

Thermal reaction of Pt film with 〈110〉 GaN epilayer

Contact Info

Product

Resources

About