Growth characteristics of Fe-doped GaN epilayers on SiC (001) substrates and their effects on high breakdown voltage devices. (15th November 2020)

• Record Type: Journal Article
• Authors: Chang, Kai-Ping; Lin, Po-Jung; Horng, Ray-Hua; Wuu, Dong-Sing
• Is Part Of: Materials science in semiconductor processing. Volume 119(2020)
• Publication Date: 2020-11-15
• Subjects: Fe-doped GaN -- Semi-insulating SiC -- Surface morphology -- Segregation -- Metalorganic chemical vapor deposition -- Two-dimension electron gas; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2020.105228
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: The growth characteristics of Fe-doped GaN epitaxial layers on semi-insulating SiC (001) substrates were studied using metalorganic chemical vapor deposition for high breakdown voltage device applications. A smooth Fe-doped GaN epilayer surface can be realized by changing the ferrocene flow, while higher Fe concentrations in the GaN epilayer affect the surface morphology. To reduce the Fe trapping carrier and the sheet resistances of the two-dimension electron gas generated from the interface of AlGaN and GaN, the thickness ratio of Fe-doped and undoped GaN bi-epilayers was also optimized. AlGaN/GaN high electron mobility transistors with the optimum doping concentration of Fe-doped GaN and suitable thickness of undoped GaN have been successfully developed. The achieved breakdown voltage of the Fe-doped GaN epitaxial layer can be as high as 2457 V, which is attributed to the Fe-doped GaN epitaxial layer with higher resistance, which can sustain the high breakdown voltage. The details of the correlation between the surface morphology, Fe concentration, and thickness of Fe-doped GaN epitaxial layers used for high breakdown voltage devices will be also discussed in this paper. Highlights: A smooth surface of Fe-doped GaN epilayer on SiC (001) can be achieved by MOCVD. Thickness of Fe-doped/undoped GaN bi-epilayer is confirmed to be a key issue. Segregation will make Fe penetrating the 2DEG structures, trapping the carriers. A high breakdown voltage of 2457 V in Fe-doped GaN epitaxial layer is achieved.