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Influence of Growth Parameters on a‐Plane InGaN/GaN Heterostructures on r‐Sapphire
Author(s) -
Orlova Marina,
Abdullaev Oleg,
Mezhenny Michail,
Chelny Alexander,
Savchuk Alexander,
Ermoshin Ivan,
Rabinovich Oleg,
Didenko Sergey,
Osipov Yuri,
Kourova Natalya,
Akhmerov Yuri,
Marenkin Sergey
Publication year - 2019
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201800371
Subject(s) - materials science , sapphire , heterojunction , metalorganic vapour phase epitaxy , dislocation , indium , amorphous solid , doping , scanning electron microscope , growth rate , quantum well , substrate (aquarium) , acceptor , optoelectronics , analytical chemistry (journal) , layer (electronics) , epitaxy , crystallography , nanotechnology , condensed matter physics , optics , chemistry , composite material , laser , geometry , physics , mathematics , oceanography , chromatography , geology
The n‐type and p‐type a‐GaN films are successfully grown by MOCVD on the r‐sapphire substrate with smooth mirror surface morphology. The growth rate versus the growth temperature is investigated. Optimum doping parameters by acceptor and donor impurities − 8 × 10 17 and 4 × 10 18 cm −3 are determined. Low‐temperature amorphous buffer (nucleus) GaN layer and the island growth process with additional doping profile in quantum wells (QW) are investigated. The heterostructures are grown based on direct investigation and simulation results and are investigated by atomic‐force microscopy (AFM) and scanning electron microscopy (SEM). In this work, V‐defects of the structure for non‐polar orientation films are investigated for the first time, thus complementing earlier results for polar and semi‐polar films. The results indicate that the defect density was reduced up to 10 4 cm −2 , with improved surface morphology uniformity. During growth, the influence from V/III flow ratio and doping barriers by indium atoms was detected. Decrease in the V/III ratio up to 1320 at the overgrowth stage of the precipitated low‐temperature nuclei caused growth‐island formation and increased the growth rate in the lateral direction, thus decreasing the dislocation density.