Metalorganic chemical vapor deposition growth and thermal stability of the AlInN/GaN high electron mobility transistor structure

Abstract

The Al x In 1−x N barrier high electron mobility transistor (HEMT) structure has been optimized with varied barrier composition and thickness grown by metalorganic chemical vapor deposition. After optimization, a transistor structure comprising a 7 nm thick nearly lattice-matched Al 0.83 In 0.17 N barrier exhibits a sheet electron density of 2.0 × 10 13 cm −2 with a high electron mobility of 1540 cm 2 V −1 s −1 . An Al 0.83 In 0.17 N barrier HEMT device with 1 μm gate length provides a current density of 1.0 A mm −1 at V GS = 0 V and an extrinsic transconductance of 242 mS mm −1 , which are remarkably improved compared to that of a conventional Al 0.3 Ga 0.7 N barrier HEMT. To investigate the thermal stability of the HEMT epi-structures, post-growth annealing experiments up to 800 • C have been applied to Al 0.83 In 0.17 N and Al 0.3 Ga 0.7 N barrier heterostructures. As expected, the electrical properties of an Al 0.83 In 0.17 N barrier HEMT structure showed less stability than that of an Al 0.3 Ga 0.7 N barrier HEMT to the thermal annealing. The structural properties of Al 0.83 In 0.17 N/GaN also showed more evidence for decomposition than that of the Al 0.3 Ga 0.7 N/GaN structure after 800 • C post-annealing.

Post-deposition annealing of magnetron sputtered InAlN film at different temperatures

“…The literature survey reveals that the post-deposition annealing behavior of InAlN film has been rarely focused in the past. Only a few studies have reported the postdeposition annealing effects on the structural and electrical properties of In x Al 1-x N films [25][26][27].…”

Investigation of InAlN Layers Surface Reactivity after Thermal Annealings: A Complete XPS Study for HEMT

“…33 Such superficial chemical variations can harm the quality of 2DEG density, decreasing also the electron mobility and the sheet carrier density when temperatures above 800 • C are employed. [34][35][36] On the basis of previous considerations, if we consider binary compounds separately, AlN is known to be stable up to 1250 • C, 37 whereas InN is known to be stable up to 550 • C [38][39][40] and decomposes above this temperature into N 2 and liquid In. Only few studies concern the chemical stability of InAlN layers through annealing temperatures.…”

INFLUENCE OF ANNEALING TREATMENT ON THE PHYSICAL PROPERTIES OF InAlN FILMS

“…On the other hand, the postgrowth annealing of InAlN¯lm has barely been focused in the past due to di®erences in the thermal stabilities of InN and AlN. [15][16][17] Recently, our group studied the e®ects of post-deposition annealing temperatures (250-700 C) on the structural surface and optical properties of InAlN¯lms prepared using a magnetron co-sputtering technique. 17 The results obtained indicated a very small improvement in the crystallinity of InAlN¯lm after annealing at 500 C, however, crystalline quality of the¯lm was signi¯cantly improved at 700 C.…”