Regensburg 2025 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 39: Poster III
HL 39.3: Poster
Wednesday, March 19, 2025, 15:00–18:00, P3
Investigating the Electrical Properties of Distributed Polarization Doped AlxGa1-xN Heterostructures via Capacitance-Voltage Measurements — •Thibaut Ehlermann1, Marcel Schilling1, Massimo Grigoletto1,2, Jakob Höpfner1, Tim Wernicke1, and Michael Kneissl1,2 — 1Technische Universität Berlin — 2Ferdinand-Braun-Institut (FBH)
Distributed Polarization Doping (DPD) enables the generation of charge carriers in wide-bandgap semiconductors like AlGaN by utilizing the material’s inherent polarization properties without the introduction of impurities. Linearly graded AlGaN DPD layers were grown by metal-organic vapor phase epitaxy (MOVPE). The starting Al mole fraction was always 100%. The thickness and end mole fraction were varied. The charge carrier concentration NA was determined from CV-measurements. For a 100 nm thick AlGaN DPD layer (x=100% –> 60%), the charge carrier concentration is NA= 1.4· 1018 1/cm3, closely matching the theoretical value of NA= 1.72· 1018 1/cm3, based on the calculated intrinsic polarization. Thicker DPD layers lead to a lower doping concentration and AlGaN DPDs (x=100% –> 80%) result in lower doping concentrations in agreement with the calculated values. The consistency of the results suggest that DPD is a reliable and promising way for p-type doping in AlGaN.
Keywords: DPD; AlGaN; charge carrier concentration; Distributed Polarization Doping; MOVPE