Detection of deep-level defects and reduced carrier concentration in Mg-ion-implanted GaN before high-temperature annealing

Abstract

Large electron capture-cross-section of the major nonradiative recombination centers in Mg-doped GaN epilayers grown on a GaN substrate

Effects of Dosage Increase on Electrical Properties of Metal‐Oxide‐Semiconductor Diodes with Mg‐Ion‐Implanted GaN Before Activation Annealing

“…This result is in good agreement with the previous report . In addition, this energy level is close to that derived by the simulation of C–V characteristics of the low‐dosage sample in the previous works . The energy position and σ of level A were E C − 0.18 eV and 4.5 × 10 −17 cm 2 for the low‐dosage sample, whereas for high‐dosage sample, E C − 0.19 eV and 8.0 × 10 −17 cm 2 , respectively.…”

“…According to the PAS results, the divacancy is the dominant defect in as‐implanted GaN, which is in good agreement with the present result for the high‐dosage sample. In contrast, for the low‐dosage sample, the dominant deep level, B, was detected at E C − 0.83 eV, which is also in good agreement with the previous reports . In the study by Akazawa and Uetake, a possible mechanism was discussed, in which V Ga and V N exist separately in the low‐dosage sample, whereas the divacancy is mainly formed in a sample with a higher dosage.…”

“…Without long‐term 600 °C annealing, the C–V curves show anomalous shapes compared with the ideal curve, as shown in Figure a. The plateau region and anomalously steep region indicate the existence of an acceptor‐type discrete state in the band gap, as discussed in detail in previous works . Note that the anomalous behavior was much improved by long‐term 600 °C annealing, as shown in Figure b, where the hysteresis and frequency dispersion are minimized without showing a plateau region.…”

“…Nevertheless, a new clue to control the defects generated by Mg‐ion implantation might be found by applying low‐temperature annealing. Recently, it was reported that annealing at 800 °C for 3 min after Mg‐ion implantation reduced the density of the deep‐level states in lightly Mg‐ion‐implanted GaN . A detailed deep‐level transient spectroscopy (DLTS) study has been conducted to investigate the effect of low‐temperature annealing for 1 min on defects generated by Mg‐ion implantation at a low dosage .…”

Electrically active point defects in Mg implanted n-type GaN grown by metal-organic chemical vapor deposition

“…15 Furthermore, it was recently reported that at !500 C, the carrier concentration of Mg implanted metal-organic vapor phase epitaxy (MOVPE) GaN recovers to the as-grown levels. 16 In order to identify those defects responsible for compensation, Saarinen et al 17 have shown that V Ga is the main compensating center in N-rich MOCVD GaN. This is also confirmed by theory that predicts a lower formation energy of the single negative charge state of V Ga in N-rich rather than Ga-rich conditions.…”