Improved surface morphology of a Ti/Al/Ni/Au ohmic contact for AlGaN/GaN heterostructure by Al2O3 particles. Issue 12 (December 2015)

• Record Type: Journal Article
• Authors: Lim, Jin Hong; Kim, Jeong Jin; Yang, Jeon Wook
• Is Part Of: Microelectronics and reliability. Volume 55:Issue 12 Part A(2015)
• Page Start: 2565
• Page End: 2568
• Publication Date: 2015-12
• Subjects: GaN -- HEMT -- Ohmic -- Morphology -- Al2O3; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2015.10.005
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: An effective method to improve the surface morphology of a Ti/Al/Ni/Au ohmic contact on an AlGaN/GaN heterostructure was proposed. The ohmic contact with the Al2 O3 particles prepared before metal deposition had a much smoother surface than the conventional ohmic contact with surface roughness of 116 nm and 195 nm, respectively, when the metal was annealed at 850 °C for 60 s. Also, the enlargement of the alloy lump was negligible at longer annealing times and higher temperatures. The ohmic contact has a contact resistivity of 3.9 × 10 − 6 Ω-cm 2, which is slightly higher than the resistivity of the contact without Al2 O3 . Highlights: An effective method to improve the surface morphology of an ohmic contact on an AlGaN/GaN heterostructure was proposed. The Ti/Al/Ni/Au ohmic contact with the Al2 O3 particles had a much smoother surface than the conventional ohmic contact. The enlargement of the alloy lump was negligible at longer annealing times and higher temperatures.