Influence of Growth Parameters on a‐Plane InGaN/GaN Heterostructures on r‐Sapphire. Issue 5 (14th March 2019)

• Record Type: Journal Article
• Authors: Orlova, Marina; Abdullaev, Oleg; Mezhenny, Michail; Chelny, Alexander; Savchuk, Alexander; Ermoshin, Ivan; Rabinovich, Oleg; Didenko, Sergey; Osipov, Yuri; Kourova, Natalya; Akhmerov, Yuri; Marenkin, Sergey
• Is Part Of: Physica status solidi. Volume 256:Issue 5(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-03-14
• Subjects: doping -- films -- GaN -- growth -- heterostructures -- InGaN -- simulation; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201800371
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract : 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. Abstract : a‐GaN single‐crystal films are successfully grown on r‐sapphire by MOCVD. V‐defects on the c‐plane are investigated for non‐polar orientation films for the first time. InGaN/GaN are grown based on the doping profile and investigated by AFM/SEM. Influence of the V/III flow ratio and of doping barriers by indium atoms on the defects is detected. The defect density is reduced to 10 4 cm −2 simultaneously with improved surface morphology uniformity.