The effect of annealing on the surface morphology of strained and unstrained InxAl1−xN thin films

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

“…8,18,19 The main difficulty resides in making a high crystalline quality and a good homogeneity of In-AlN layers, 20,21 InN and AlN suffering from a large difference of covalent bond, resulting from phase separation and strong spinodal decomposition. 22,23 Nevertheless, MBE [24][25][26] and also MOVPE 27,28 are both leading to excellent composition uniformity and good device performances with thin-layer engineering around 7 nm of thickness. 8,29 During the fabrication process of the HEMT, the InAlN/GaN layers have to go through different steps: (1) chemical treatments to prepare the surface, (2) voluntary oxidation at high temperature under O 2 oxygen and Ar, (3) Ti/Al/Ni/Au/Ti/Pt ohmic contacts stack deposition (e-gun evaporation) followed by a thermal annealing (> 800 • C) under N 2 atmosphere, (4) oxide layer openings and Ar+ implantation for z E-mail: yoan.bourlier@uvsq.fr device electrical isolation before E-beam lithographed T-gates contact (Ni/Pt/Au metal stack) deposition (e-gun evaporation), and ( 5) passivation of the device with a 150-nm thick Si 3 N 4 film deposited by plasma enhanced chemical vapor deposition (PECVD).…”

Structural characterization of indium-rich nanoprecipitate in InGaN V-pits formed by annealing

“…These applications of annealing have the same effects on III-nitride semiconductors. Moreover, many researchers have investigated the micro-structural changes of GaN, [3,4] InGaN, [5,6] and InAlN [7] induced by breaking of chemical bonds during annealing. This makes it more attractive to remove the phase separation in rich indium content alloys by annealing.…”

Growth of AlInN/GaN distributed Bragg reflectors with improved interface quality

“…Special cause has therefore to be addressed to the change of the conditions between growth of the subsequent AlInN and GaN layers. Exposure of AlInN to a steep temperature ramp during transition to GaN growth sequence leads changed surface morphologies supposedly be caused by indium desorption [10][11][12]. Sadler et al [13] proposed to optimize AlInN overgrowth by growing the first 10 nm of the GaN layer sequence at the same temperature as the AlInN layer and the rest at optimum GaN growth temperatures.…”