Premium
GaN Micropillar Schottky Diodes with High Breakdown Voltage Fabricated by Selective‐Area Growth
Author(s) -
Debald Arne,
Kotzea Simon,
Riedel Jona,
Heuken Michael,
Kalisch Holger,
Vescan Andrei
Publication year - 2020
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201900676
Subject(s) - materials science , schottky diode , optoelectronics , breakdown voltage , doping , diode , sapphire , electric field , schottky barrier , layer (electronics) , voltage , nanotechnology , electrical engineering , optics , engineering , laser , physics , quantum mechanics
Herein, selective‐area growth (SAG) of lightly n‐doped GaN micropillars on masked GaN‐on‐sapphire templates is investigated. Using the micropillar SAG approach, the maximum GaN drift layer thickness in Schottky diodes on foreign substrates is increased. Thus, cost‐efficient vertical power devices with large breakdown voltages ( V BD ) based on heteroepitaxy are enabled. The influence of different hard‐mask materials and SAG temperatures ( T SAG ) on growth selectivity, morphology, and net doping concentration ( N D – N A ) is investigated. By using an AlO x hard mask and T SAG = 1045 °C, 3.7 μm high GaN micropillars are grown in circular mask openings. Quasi‐vertical Schottky diodes on these pillars exhibit low N D – N A = 5.2 × 10 16 cm −3 , V BD = 393 V, and a critical electric field E C = 2.63 MV cm −1 .