Growth and Properties of Intentionally Carbon‐Doped GaN Layers. Issue 2 (22nd October 2019)

• Record Type: Journal Article
• Authors: Richter, Eberhard; Beyer, Franziska C.; Zimmermann, Friederike; Gärtner, Günter; Irmscher, Klaus; Gamov, Ivan; Heitmann, Johannes; Weyers, Markus; Tränkle, Günther
• Is Part Of: Crystal research and technology. Volume 55:Issue 2(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-10-22
• Subjects: carbon -- GaN -- HVPE -- self‐compensation -- tri‐carbon‐defect; Crystallography -- Periodicals; 548
• DOI: 10.1002/crat.201900129
• Languages: English
• ISSNs: 0232-1300

Abstract

Abstract: Carbon‐doping of GaN layers with thickness in the mm‐range is performed by hydride vapor phase epitaxy. Characterization by optical and electrical measurements reveals semi‐insulating behavior with a maximum of specific resistivity of 2 × 10 10 Ω cm at room temperature found for a carbon concentration of 8.8 × 10 18 cm −3 . For higher carbon levels up to 3.5 × 10 19 cm −3, a slight increase of the conductivity is observed and related to self‐compensation and passivation of the acceptor. The acceptor can be identified as CN with an electrical activation energy of 0.94 eV and partial passivation by interstitial hydrogen. In addition, two differently oriented tri‐carbon defects, CN ‐a‐CGa ‐a‐CN and CN ‐a‐CGa ‐c‐CN, are identified which probably compensate about two‐thirds of the carbon which is incorporated in excess of 2 × 10 18 cm −3 . Abstract : Evidence for incorporation of carbon atoms at Ga sites in form of tri‐carbon defects in highly C‐doped GaN layers is provided. This way, about two‐thirds of carbon in excess of 2 × 10 18 cm −3 are compensated. This accounts for an optimum of carbon concentration in the upper 10 18 cm −3 range for the fabrication of semi‐insulating layers in electronic devices.