Effects of chemical treatment on barrier height and ideality factors of Au/GaN Schottky diodes

Abstract

a b s t r a c tWe have studied Au/n-GaN Schottky barrier diodes. GaN surfaces have been prepared by cleaning in HCl and (NH 4 ) 2 S prior to metal deposition. The zero-biased barrier heights and ideality factors obtained from the current-voltage characteristics differ from diode to diode, although all the samples were prepared identically. The statistical analysis for the reverse bias C-V data yielded mean value of (1.357 0.04) eV for Schottky barrier height of HCl treated sample and (1.20 7 0.03) eV for (NH 4 ) 2 S sample, where 9 dots were considered from each cleaning method. It was found that the barrier height values obtained from the C À 2 -V (1.43 eV) and I-V characteristics (0.89 eV) are different from each other by 0.54 eV. The inhomogeneous barrier heights were found to be related to the effect of the high series resistance on diode parameters [1].

The effect of high temperatures on the electrical characteristics of Au/n-GaAs Schottky diodes

“…According to the Schottky-Mott theory, depletion layer capacitance can be expressed as [29]: (4) where, A is the diode area, V bi the diffusion potential at zero bias obtained from the extrapolation of the linear C -2 -V plot to the V axis; and, V A is the applied voltage. The capacitance of a Schottky diode is characterised by the width of the depletion layer [30].…”

Barrier height modification in Au/Ti/n-GaAs devices with a $$\hbox {HfO}_{2}$$ HfO 2 interfacial layer formed by atomic layer deposition

“…The BH modification in the MS rectification contacts can be achieved by means of some experimental methods such as nitridation pretreatment [15,16] or different chemical treatments [17,18] of the semiconductor surface, the deposition of thin interfacial passivation layers [15,16] and formation of an oxide layer by anodic oxidation [19] or thermal oxidation [20] or a sulphide insulating layer by anodic sulphidization [21] on the semiconductor substrate surface; or the thermal annealing of the device after Schottky and ohmic metallization [5][6][7][8][9]. These processes and the interfacial layers play important roles in the formation of the BH.…”

Electrical properties and interfacial reactions of rapidly annealed Ni/Ru Schottky rectifiers on n-type GaN

“…Many researchers have explored various metal schemes for the fabrication of Schottky contacts on n-type GaN, e.g., Rh/Au [9], Ir/Pt [10], Au and Ti/Au [11], Rh [12], Ru/Au [13], Pt [14], Pd, Pt and Ni [15], Au [16], Al/Ni/Au [17], Pt/Mo [18], Ni/AlN/GaN/AlN [19], Ni [20], Ni/Mo [21], Ir/Pt [22], etc. Dobos et al [11] investigated the structural and electrical properties of Au and Ti/Au contacts to nGaN and found that the contacts were rectifying up to 700 • C and the highest barrier height of 1.07 eV was obtained for Au single layer.…”