Thermally stable rhenium Schottky contacts to n-GaN

Abstract

The barrier heights of Re Schottky contacts to n-GaN were investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements. Both techniques indicate that the barrier height increases upon annealing at 500 °C for 10 min. After this anneal, a barrier height of 0.82 eV and ideality factor of 1.1 are obtained by I–V measurements performed at 150 °C. The C–V measurements performed at room temperature reveal a barrier height of 1.06 eV. These barrier heights are stable upon further short term annealing at temperatures as high as 700 °C. The Re Schottky contacts were also stable upon prolonged annealing for 24 h at 300 °C. The Re/n-GaN Schottky diode was chosen for study because of its anticipated thermodynamic stability against metallurgical reactions.

Electrical and structural properties of low-resistance Ti/Al/Re/Au ohmic contacts to n-type GaN

“…[10][11][12][13][14][15][16][17] In this work, refractory metal Re was introduced as a capping layer because it is thermally stable. 18 In other words, the Re/Au capping layer is expected to protect the Ti/Al layer against oxidation and, consequently, to improve the ohmic property of the Ti/Al contact. It is shown that the Ti/Al/Re/Au contacts produce specific contact resistance as low as 1.3 ϫ 10 Ϫ6 Ωcm 2 when annealed at 750°C for 1 min in a nitrogen ambient.…”

Electronic transport and Schottky barrier heights of Pt/n-type GaN Schottky diodes in the extrinsic region

“…Recent studies of Schottky contact properties on n-type GaN have been published. [11][12][13][14][15][16][17] It is great importance to study temperaturedependent electrical characteristics if the current transport mechanism of the Schottky diode is to be elucidated. Khan et al 18 stated that the temperature dependence of the currentvoltage ͑I-V͒ characteristics showed two regimes of forward current transport: one at low voltage governed by thermionic emission ͑TE͒ and the high-voltage regime due to spatial inhomogeneities at the MS interface.…”

Electrical characteristics and thermal stability of W, WSiN, and Nb contacts to p- and n-type GaN

“…9,[14][15][16][17][18][19][20][21][22][23][24][25] In most of these studies, the results of x-ray diffraction, Rutherford backscattering spectroscopy, and Auger electron spectroscopy are correlated with the contact resistance of ohmic contacts and the barrier height of Schottky contacts formed on n-GaN as a function of high-temperature annealing. 9,[14][15][16][17][18][19][20][21][22][23][24][25] In most of these studies, the results of x-ray diffraction, Rutherford backscattering spectroscopy, and Auger electron spectroscopy are correlated with the contact resistance of ohmic contacts and the barrier height of Schottky contacts formed on n-GaN as a function of high-temperature annealing.…”