Ion implanted GaN MISFETs fabricated in Mg implanted layers activated by conventional rapid thermal annealing

Yoshino, Masao; Sugamata, Kota; Ikeda, K.; Nishimura, Tomoaki; Kuriyama, K.; Nakamura, Tsuneyoshi

doi:10.1016/j.nimb.2019.04.008

Cited by 14 publications

(12 citation statements)

References 10 publications

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“…Recently, a number of novel approaches using Mg ion implantation and annealing have achieved very promising results regarding p ‐type doping, e.g. multicycle rapid thermal annealing (RTA), [ 19 ] high‐temperature implantation around 500 [ 19–21 ] or 1000 °C, [ 22 ] ultra‐high‐pressure annealing, [ 8,23–24 ] microwave annealing, [ 21 ] pulsed laser annealing, [ 25 ] or co‐implantation of N. [ 26 ] However, also conventional RTA [ 20,27,28 ] or furnace annealing [ 29,30 ] have been reported successful and suitable for creating devices such as visible‐blind photodiodes [ 29 ] or power rectifiers. [ 30 ]…”

Section: Introductionmentioning

confidence: 99%

Lattice Location Studies of the Amphoteric Nature of Implanted Mg in GaN

Wahl

Correia

Costa

et al. 2021

Adv Elect Materials

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Despite the renewed interest in ion implantation doping of GaN, efficient electrical activation remains a challenge. The lattice location of 27Mg is investigated in GaN of different doping types as a function of implantation temperature and fluence at CERN's ISOLDE facility. The amphoteric nature of Mg is elucidated, i.e., the concurrent occupation of substitutional Ga and interstitial sites: following room temperature ultra‐low fluence (≈2 × 1010 cm−2) implantation, the interstitial fraction of Mg is highest (20–24%) in GaN pre‐doped with stable Mg during growth, and lowest (2–6%) in n‐GaN:Si, while undoped GaN shows an intermediate interstitial fraction of 10–12%. Both for p‐ and n‐GaN prolonged implantations cause interstitial 27Mg to approach the levels found for undoped GaN. Implanting above 400 °C progressively converts interstitial Mg to substitutional Ga sites due to the onset of Mg interstitial migration (estimated activation energy 1.5–2.3 eV) and combination with Ga vacancies. In all sample types, implantations above a fluence of 1014 cm−2 result in >95% substitutional Mg. Ion implantation is hence a very efficient method to introduce Mg into substitutional Ga sites, i.e., challenges toward high electrical activation of implanted Mg are not related to lack of substitutional incorporation.

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Section: Introductionmentioning

confidence: 99%

Lattice Location Studies of the Amphoteric Nature of Implanted Mg in GaN

Wahl

Correia

Costa

et al. 2021

Adv Elect Materials

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“…16 Therefore, high temperature post-implantation annealing is essential for promoting Mg substitution, thus increasing the electrical activation. [17][18][19][20][21] However, the thermal treatment also induces Mg diffusion and segregation. 22,23 In order to achieve reasonable p-type conductivity with free hole concentrations up to 10 18 cm À3 , a large dosage of Mg implantation is required.…”

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confidence: 99%

Mg diffusion and activation along threading dislocations in GaN

Kumar

Uzuhashi

et al. 2020

Applied Physics Letters

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The precise control of p-GaN is a crucial issue for developing GaN-based power devices. Mg as an acceptor is commonly used in p-type doping; however, the Mg diffusion through threading dislocations (TDs) has not been well addressed. To clarify the Mg diffusion and activation along TDs, we have performed a systematic characterization of a Mg-implanted homoepitaxial GaN layer grown on a freestanding substrate. Active-Mg related donor-acceptor pair (DAP) emission from certain TDs is identified by cathodoluminescence (CL). Dislocations with and without DAP emission are investigated structurally and compositionally based on etch pits, transmission electron microscopy, and atom-probe tomography. Direct evidence of Mg distribution around edge-and mixed-type TDs is obtained. There exists a significant difference in the Mg concentration and incorporation states between different types of TDs.

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“…In recent years, it has been reported that a p–n junction can be formed by Mg ion implantation by using a high‐quality free‐standing GaN substrate, and rectification characteristics and electroluminescence have been observed . In addition, the operation of a MOSFET using a Mg‐ion‐implanted layer has also been confirmed . One of the most serious problems of Mg ion implantation is the formation of V N , which cannot be repaired by postimplantation annealing.…”

Section: Introductionmentioning

confidence: 97%

Suppression of Green Luminescence of Mg‐Ion‐Implanted GaN by Subsequent Implantation of Fluorine Ions at High Temperature

Takahashi

Tanaka

Ando

et al. 2019

Physica Status Solidi (b)

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Herein, gallium nitride (GaN) samples implanted with magnesium (Mg) and fluorine (F) ions are investigated by photoluminescence (PL) measurements. In low‐temperature PL measurements, the characteristic green luminescence (GL) band attributable to nitrogen vacancies (VN) is observed in Mg‐ion‐implanted GaN. As VN are likely to act as donors, suppressing their formation is essential to realizing p‐type conductivity. The energy required for a F impurity to replace VN in GaN and eventually form F on a N site decreases when the Fermi level approaches the valence band maximum, and therefore F is employed as a subsequent implantation element to compensate for VN. The GL band peak disappears upon implanting Mg and F ions at a high temperature and adjusting the F concentration to an appropriate value. This result suggests that VN generated by Mg ion implantation can be suppressed using an element with a lower formation energy than that of VN.

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Ion implanted GaN MISFETs fabricated in Mg implanted layers activated by conventional rapid thermal annealing

Cited by 14 publications

References 10 publications

Lattice Location Studies of the Amphoteric Nature of Implanted Mg in GaN

Lattice Location Studies of the Amphoteric Nature of Implanted Mg in GaN

Mg diffusion and activation along threading dislocations in GaN

Suppression of Green Luminescence of Mg‐Ion‐Implanted GaN by Subsequent Implantation of Fluorine Ions at High Temperature

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