Identification of swift heavy ion induced defects in Pt/n-GaN Schottky diodes by in-situ deep level transient spectroscopy

Abstract

In-situ measurements such as deep level transient spectroscopy (DLTS) provide reliable information for the identification of defects in electronic devices. For GaN-based devices exposed to swift heavy ion (SHI) irradiation, in situ DLTS investigations are not reported. The defect characterization of irradiated devices has significant relevance in the reliability testing of devices for space applications, detectors for high energy physics experiments, nuclear radiation environments near reactors and for device engineers to design better and high-performance electronic components. The present work reports on the identification of defects by employing in situ DLTS in Pt/n-GaN Schottky devices before and after SHI irradiation by 200 MeV 107 Ag 14+ ions at various fluences in the range of 1×10 10 to 1×10 11 ions cm −2 . For pristine or un-irradiated diodes, trap levels at 0.173, 0.504, 0.283 and 1.012 eV below the conduction edge are observed which are reported as growth-related defects in GaN. The ion beam introduces more electron and hole traps in the bandgap. A significant increase in interface state density was instigated by irradiation which practically pinned the Schottky barrier height at 0.73 eV at an experimental time scale. The origin of these defects was compared and discussed based on literature.

Apparatus for Seebeck coefficient measurement of wire, thin film, and bulk materials in the wide temperature range (80–650 K)

“…This may be due to the different growth methods of films adopted and different carrier concentration profiles. The films in the reported data [42] are grown by molecular beam epitaxy (MBE) and has higher carrier concentration (2×10 18 /cm 3 ) compared to our sample (~4×10 16 /cm 3 ) [43,44]. The detailed mechanism of the observed trend of Seebeck coefficient in GaN is affected by defects present and may also involve secondary transport mechanisms [42,45].…”

The Sliding-Aperture Transform and Its Applicability to Deep-Level Transient Spectroscopy

“…This removes user intervention from the process of rate and peak height determination and is not only the strength of this work but is prominent attribute for both L-DLTS and deep-level Fourier spectroscopy [6,7,23]. SLAP offers another means of characterizing defect spectrum through the sequential use of Equation (10), first under the assumption of a single defect (i.e., i = 1, k = 1), followed by the introduction of more defect species (i.e., k > 1).…”

“…Semiconductor-based components in harsh environments, such as infrared sensors in space, accumulate electrically active defects due to radiation damage [8][9][10][11][12][13][14]. Such defects act as recombination and charge compensation centers and thereby affect minority carrier lifetime and free carrier concentration, which degrade circuit functionality.…”

Medium Energy Carbon and Nitrogen Ion Beam Induced Modifications in Charge Transport, Structural and Optical Properties of Ni/Pd/n-GaN Schottky Barrier Diodes

“…Studies on ion irradiation-induced effects in GaN semiconductor devices have been reported in the literature. Studies on GaN-based electronic devices irradiated by different SHIs have reported the formation of nano-tracks in GaN, development of nano-holes on the GaN surface, and an increase in resistivity of GaN [21][22][23][24]. The ion implantation of GaN by low energy ions reported the doping and amorphization of GaN [25,26].…”

“…Such damage not only induces micro-structural change, but also leads to a change in electrical properties. Most of the previous studies were performed on low-energy ion implantation and on the swift heavy ion (SHI) irradiation [21,22,[27][28][29][30][31][32][33], but there have been only a few studies reporting on MEI irradiation [34,35]. Therefore, the investigation of the impacts of MEI irradiation on semiconductors and their device properties is important both from a fundamental and technological point of view.…”