Inductively coupled plasma damage in GaN Schottky diodes

Abstract

The effects of H2 or N2 plasma exposure on the current–voltage characteristics of GaN Schottky diodes were examined as a function of source power and rf chuck power. Under all conditions there was a strong reduction in diode reverse breakdown voltage and an increase in forward and reverse currents. The results are consistent with creation of a thin (⩽600 Å) n-type conducting surface region after ion bombardment of the GaN surface. Much of the degradation in diode quality can be recovered by annealing in N2 at 750 °C.

Plasma-etching-enhanced deep centers in n-GaN grown by metalorganic chemical-vapor deposition

“…Plasma-etching damage has been studied mainly by analyzing current-voltage characteristics of Schottky barrier diodes ͑SBDs͒ made on the damaged GaN surface, in conjunction with various etching and annealing conditions. [1][2][3] It is believed that the degraded I -V characteristics are associated with etching-induced defects, which, however, have not yet been elucidated. In this work, we use deep-level transient spectroscopy ͑DLTS͒ to demonstrate that a well-known trap is strongly enhanced in n-GaN by plasma etching.…”

Deep etch-induced damage during ion-assisted chemical etching of sputtered indium–zinc–oxide films in Ar/CH4/H2 plasmas

“…Depending on the material etched and the plasma chemistry used, the damage may take the form of point defects and their complexes, changes in near-surface stoichiometry, presence of residual etch products or deposition of polymers. A number of experiments have confirmed the presence of these various forms of etch-induced damage using electrical, optical, and structural characterization techniques [1][2][3][4][5][6][7][8][9][10][11][12]. For physical sputtering, depth profile measurements have indicated that the damage induced by low ion energy bombardment can extend deeper than the predicted ion stopping range because of both ion channeling and defect diffusion [9][10][11][12][13].…”

A different approach to solar cell simulation

“…Various metals such as Au, Pd, Ni and Pt can be used for the fabrication of n-GaN Schottky contact. Light transmittance of the gold (60%) is higher than that of the nickel (30%) and Au/n-GaN photoresponse (49%) is higher than that of the Ni/n-GaN Schottky photodiode [9,10]. Also, the thermal stability limits of Au/n-GaN contact are 575 C [9,10].…”

“…Gallium nitride (GaN) is a compound semiconductor with a wide direct band gap (3.4 eV). It is a very promising material for the fabrication of LED's, solar cells for space applications, lasers, detectors, high-temperature, high-power, high-frequency transistors, photovoltaic energy conversation, fiber optic communication and atmosphere monitoring applications [1][2][3][4][5][6][7][8][9]. Various metals such as Au, Pd, Ni and Pt can be used for the fabrication of n-GaN Schottky contact.…”