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Reproducible and High-Temperature Performance of NiO/ $beta$-Ga2O3 Vertical Rectifiers in Achieving 8.9 kV Breakdown

MetadataDetails
Publication Date2023-06-25
AuthorsJian-Sian Li, Chao-Ching Chiang, Xinyi Xia, Hsiao-Hsuan Wan, F. Ren
InstitutionsUniversity of Florida

The increasing electrification of automobiles and the need to switch renewable energy sources in the existing power grid has increased the demand for energy-efficient power electronics capable of higher voltage and currents than existing Si devices. This has focused attention on the wide and ultra-wide bandgap semiconductors, with the latter including diamond, AlN and Ga <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/inf> O <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;3&lt;/inf> . The ability to grow large-diameter, high-quality crystals and the attendant low cost of production has spurred interest in <tex xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;&#36;\beta&#36;&lt;/tex> -Ga <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/inf> O <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;3&lt;/inf> . [1] The lack of p-type doping options for Ga <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/inf> O <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;3&lt;/inf> has led to the use of p-type oxides to form p-n heterojunctions with the n-type Ga <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/inf> O <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;3&lt;/inf> . The most successful has been NiO, deposited by sputtering.[2]-[4] Optimizing the heterojunction rectifier device structure is crucial to achieve a high-power figure of merit (FOM) for power electronic devices, defined as (V <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;B&lt;/inf> ) <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sup> /R <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;ON&lt;/inf> where V <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;B&lt;/inf> is the reverse breakdown voltage and R <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;ON&lt;/inf> -is the on-state resistance. A less studied aspect has been the elevated temperature performance of such devices. We report an investigation of the uniformity of achieving high V <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;B&lt;/inf> and low R <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;ON&lt;/inf> , as well as the temperature dependent performance of NiO/Ga <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/inf> O <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;3&lt;/inf> vertical rectifiers. A new highest V <inf xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;B&lt;/inf> and highest-temperature voltage blocking capability for these devices are achieved.