Tuning electrical conductivity of β-Ga2O3 single crystals by Ta doping

Cui, Huiyuan; Mohamed, H.F.; Xia, Changtai; Sai, Qinglin; Zhou, Wei; Hu, Qi; Zhao, Jimin; Si, Jiliang; Ji, Xiaoli

doi:10.1016/j.jallcom.2019.02.076

Cited by 54 publications

(30 citation statements)

References 17 publications

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“…Secondary Ion Mass spectroscopy (SIMS), was not possible to quantify Hf concentration due to the lack of standards, but the Hf existence has been confirmed with energy dispersive x-ray spectroscopy (EDS) in our Hf doped samples as shown in the Supplementary Material. Finally, GDMS on the Hf-doped samples has been conducted and is shown in the Supplementary Materials; the GDMS results show Hf of 1.3x10 19 atoms/cm 3 which is close to the measured n and confirm the incorporation of Hf, and show Si, Zr, and Fe to be 2.5x10 17 atoms/cm 3 , 2.1x10 17 atoms/cm 3 , and 8.3x10 16 atoms/cm 3 , respectively. Sn and Ge were below the detection limits.…”

Section: Resultssupporting

confidence: 58%

“…Hall measurements on twelve Hf-doped samples obtained from different locations from the same boule show the electron concentration at room temperature (n) to vary between 7.5x10 18 cm -3 to 1.9x10 19 cm -3 and resistivity between 12.5mΩ-cm to 5.2mΩ-cm; eight of the Hf-doped samples are shown as example in Table 1. The variation shows that n, and in-turn the Hf concentration, increases vertically toward the bottom of the boule indicating a segregation coefficient of less than 1, and decreases radially toward the edges of the boule indicating a possible convex solid/liquid interface; this interface increases the tendency of spiral growth, and the interface is also typical for highly doped and conductive β-Ga2O3 due to free carrier absorption.…”

Section: Resultsmentioning

confidence: 99%

“…Si and Sn doping in bulk crystals have been limited to 2x10 19 cm -3 due to the second phase formation and crystal quality degradation with Si doping [16], and high evaporation rate of Sn [13,14]. Ge-doped β-Ga2O3, to our knowledge, has never been grown as bulk single crystals due to the high vapor pressure of Ge.…”

Section: Introductionmentioning

confidence: 99%

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Degenerate doping in β-Ga₂O₃ single crystals through Hf-doping

Saleh

Varley

Jesenovec

et al. 2020

Semicond. Sci. Technol.

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n-type conductivity of β-Ga2O3 grown from the melt is typically achieved using Sn and Si. In this paper, we experimentally and computationally investigate Hf doping of β-Ga2O3 single crystals using UV-Vis-NIR absorption and Hall Effect measurements and hybrid functional calculations. Unintentionally-doped and Hf-doped samples with a nominal concentration of 0.5at% were grown from the melt using vertical gradient freeze (VGF) and Czochralski method in mixed Ar+O2 atmosphere. We demonstrate Hf dopants, predicted to incorporate on the octahedral GaII site as a shallow donor, achieve degenerate doping in β-Ga2O3 with a measured electron concentration ~2x10 19 cm -3 , mobility 80-65cm 2 /Vs, and resistivity down to 5mΩ-cm in our samples. The concentration of Hf was measured to be 1.3x10 19 atoms/cm 3 using glow discharge mass spectroscopy (GDMS) on doped samples, confirming Hf to be the cause of n-type conductivity (electron concentration ~2x10 19 cm -3 ).

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Section: Resultssupporting

confidence: 58%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Degenerate doping in β-Ga₂O₃ single crystals through Hf-doping

Saleh

Varley

Jesenovec

et al. 2020

Semicond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…To our knowledge, the lowest FWHM reported is ~22 arcsec for the peak β -Ga 2 O 3 (400) by Hossain et al [ 39 ], in this work, the Laue diffraction patterns also confirmed that the grown β -Ga 2 O 3 crystal has a good crystallinity. However, FWHM of β -Ga 2 O 3 rocking curves larger than 100 arcsec has also been measured [ 38 , 53 ]. However, both these techniques mentioned above suffer from small crystal size (wafer is no more than 1 inch so far, as summarized in Table 1 .…”

Section: Gallium Oxide (Ga 2 O 3 )mentioning

confidence: 99%

Ga2O3 and Related Ultra-Wide Bandgap Power Semiconductor Oxides: New Energy Electronics Solutions for CO2 Emission Mitigation

et al. 2022

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Currently, a significant portion (~50%) of global warming emissions, such as CO2, are related to energy production and transportation. As most energy usage will be electrical (as well as transportation), the efficient management of electrical power is thus central to achieve the XXI century climatic goals. Ultra-wide bandgap (UWBG) semiconductors are at the very frontier of electronics for energy management or energy electronics. A new generation of UWBG semiconductors will open new territories for higher power rated power electronics and solar-blind deeper ultraviolet optoelectronics. Gallium oxide—Ga2O3 (4.5–4.9 eV), has recently emerged pushing the limits set by more conventional WBG (~3 eV) materials, such as SiC and GaN, as well as for transparent conducting oxides (TCO), such asIn2O3, ZnO and SnO2, to name a few. Indeed, Ga2O3 as the first oxide used as a semiconductor for power electronics, has sparked an interest in oxide semiconductors to be investigated (oxides represent the largest family of UWBG). Among these new power electronic materials, AlxGa1-xO3 may provide high-power heterostructure electronic and photonic devices at bandgaps far beyond all materials available today (~8 eV) or ZnGa2O4 (~5 eV), enabling spinel bipolar energy electronics for the first time ever. Here, we review the state-of-the-art and prospects of some ultra-wide bandgap oxide semiconductor arising technologies as promising innovative material solutions towards a sustainable zero emission society.

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“…for effective n-type doping. [27][28][29][30][31] V is typically doped into TiO 2 for photocatalytic research. 32,33 Considering the ionic radius, the radius of V 5+ (0.059 nm) is nearly the same as that of Ga 3+ (0.062 nm), and V slightly changes the lattice size of β-Ga 2 O 3 single crystals.…”

Section: Introductionmentioning

confidence: 99%