AlGaN/GaN HEMTs on diamond substrate with over 7 W/mm output power density at 10 GHz

• Published in: Electronics letters Vol. 49; no. 20; pp. 1298 - 1299
• Main Authors: Dumka, D.C, Chou, T.M, Faili, F, Francis, D, Ejeckam, F
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.09.2013; Institution of Engineering and Technology
• Subjects: AlGaN‐GaN; aluminium compounds; Amplifiers; Applied sciences; chemical vapour deposition; Circuit properties; device wafers; diamond; diamond substrate; dielectric adhering; dielectric deposition; drain bias; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; frequency 10 GHz; gallium compounds; gate length process; gate‐width HEMT; high electron mobility transistors; III‐V semiconductors; nitride transition layers; output power density; peak power‐added‐efficiency; power gain; RF performance; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductor technology; silicon; size 0.25 mum; substrates; test HEMT; Transistors; voltage 40 V; wide band gap semiconductors; gate length process; size 0.25 mum; voltage 40 V; dielectric adhering; AlGaN-GaN; RF performance; aluminium compounds; gate-width HEMT; peak power-added-efficiency; substrates; frequency 10 GHz; gallium compounds; high electron mobility transistors; dielectric deposition; nitride transition layers; test HEMT; device wafers; power gain; drain bias; chemical vapour deposition; diamond; silicon; Si; wide band gap semiconductors; diamond substrate; output power density; III-V semiconductors; GHz range; Output power; Dielectric materials; Power gain; Aluminium nitride; Diamond; Experimental study; Radiofrequency; Chemical vapor deposition; Gallium nitride; High electron mobility transistor; Transition; Power amplifier; Peak power
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2013.1973

Record RF performance of AlGaN/GaN high electron mobility transistors (HEMTs) on a diamond substrate with over 7 W/mm output power density at 10 GHz is reported. It is achieved along with the peak power-added-efficiency over 46% and power gain over 11 dB for 2 × 100 µm gate-width HEMTs at 40 V drain bias. Device wafers are prepared by first removing the host Si (111) substrate and nitride transition layers beneath the channel, depositing a 50 nm dielectric onto the exposed GaN buffer, and finally growing 100 µm of a chemical vapour deposition diamond onto the dielectric adhering to the epitaxial AlGaN/GaN. This approach enables the active GaN channel to be brought within 1 µm of the diamond substrate. Test HEMTs are fabricated using a dielectrically defined 0.25 µm gate length process.