Excimer laser annealing effects on AlGaN/GaN heterostructures

Lee, In Hak; Joo, Beom Soo; Kim, Hyuk Jin; Yun, Ye Seul; Jang, S.; Kang, Min Gyu; Kang, Chong Yun; Park, Byeong Gyu; Han, Mei; Chang, Young Jun

doi:10.1016/j.cap.2016.03.013

Cited by 6 publications

(2 citation statements)

References 29 publications

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“…It is also plausible that the O impurity level in the as-grown sample-V25c measured by SIMS was not so high, as shown in figure 4(c). However, another author shows a large increase in the Ga-O ratio, even in Ga 3d XPS peak spectra, where the samples were irradiated multiple times [66]. Nevertheless, we also found the signature of the Ga-O ratio, which is present in the O 1s XPS peak, and it was further aggravated in some other conditions.…”

Section: Sims Measurement Of the As-grown Led-v25c And The Influence ...supporting

confidence: 44%

Impact of Mg level on lattice relaxation in a p-AlGaN hole source layer and attempting excimer laser annealing on p-AlGaN HSL of UVB emitters

et al. 2020

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Mg-doped p-type semiconducting aluminium-gallium-nitride hole source layer (p-AlGaN HSL) materials are quite promising as a source of hole ‘p’ carriers for the ultraviolet-B (UVB) light-emitting diodes (LEDs) and laser diodes (LDs). However, the p-AlGaN HSL has a central issue of low hole injection due to poor activation of Mg atoms, and the presence of unwanted impurity contamination and the existence of a localized coherent state. Therefore, first the impact of the Mg level on the crystallinity, Al composition and relaxation conditions in the p-AlGaN HSL were studied. An increasing trend in the lattice-relaxation ratios with increasing Mg concentrations in the p-AlGaN HSL were observed. Ultimately, a 40%–60% relaxed and 1.4 μm thick p-AlGaN HSL structure with total threading dislocation densities (total-TDDs) of approximately ∼8–9 × 108 cm−2 was achieved, which almost matches our previous design of a 4 μm thick and 50% relaxed n-AlGaN electron source layer (ESL) with total-TDDs of approximately ∼7–8 × 108 cm−2. Subsequently, structurally a symmetric p–n junction for UVB emitters was accomplished. Finally, the influence of excimer laser annealing (ELA) on the activation of Mg concentration and on suppression of unwanted impurities as well as on the annihilation of the localized energy state in the p-AlGaN HSL were thoroughly investigated. ELA treatment suggested a reduced Ga–N bonding ratio and increased Ga–O, as well as Ga–Ga bonding ratios in the p-AlGaN HSL. After ELA treatment the localized coherent state was suppressed and, ultimately, the photoluminescence emission efficiency as well as conductivity were drastically improved in the p-AlGaN HSL. By using lightly polarized p-AlGaN HSL assisted by ELA treatment, quite low resistivity in p-type AlGaN HSL at room temperature (hole concentration is ∼2.6 × 1016 cm−3, the hole mobility is ∼9.6 cm2 V1 s−1 and the resistivity is ∼24.39 Ω. cm) were reported. ELA treatment has great potential for localized activation of p-AlGaN HSL as well as n- and p-electrodes on n-AlGaN and p-AlGaN contact layers during the flip-chip (FC) process in low operating UVB emitters, including UVB lasers.

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Section: Sims Measurement Of the As-grown Led-v25c And The Influence ...supporting

confidence: 44%

Impact of Mg level on lattice relaxation in a p-AlGaN hole source layer and attempting excimer laser annealing on p-AlGaN HSL of UVB emitters

et al. 2020

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“…The mechanism is roughly the same. [46][47][48][49][50][51][52] Eaton's group and Miyachi's group studied the effect of Minority-Carrier injection on the activation of Mg-doped GaN. The former study found that when there is a minority carrier implantation, thin, lightly doped GaN can be annealed at 175 ℃ to achieve the effect of acceptor activation, while thick, heavily doped GaN needs to be at a high temperature above 700 ℃ to activate the acceptor for effective activation, it is proposed that the thin, lightly doped P-GaN activation process satisfies a quadratic dynamic process.…”

Section: P-type Gan Materials Has a Low Carrier Concentration Due To ...mentioning

confidence: 99%

P-type Doping of Broad-band Nitride Semiconductors

Liu¹,

Cai²,

Liu³

et al. 2021

AJMC

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GaN-based optoelectronic devices have been an important development direction for semiconductors and have been applied in several fields. P-type GaN thin film implementation is the core process for optoelectronic devices, and a lot of breakthrough results have been achieved in p-GaN research. For example, Si and Mg are used as the main doping elements. However, more effective doping of GaN materials is needed in order to make GaN materials play a greater electrical and optical advantage. In this paper, we take p-GaN as the main object of study and outline the conditions that need to be satisfied for effective doping of GaN materials. Emphasizing several factors that make the quality of p-type materials of GaN a bottleneck for application development, the results achieved in p-GaN research in recent years are presented.

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