Crystal structure and epitaxial relationship of Ni4InGaAs2 films formed on InGaAs by annealing

Abstract

The structural, compositional, and electrical properties of epitaxial Ni4InGaAs2 (denoted as Ni-InGaAs) film formed by annealing sputtered Ni film on InGaAs were investigated. It was found that Ni-InGaAs adopts a NiAs (B8) structure with lattice parameters of a = 0.396 ± 0.002 nm and c = 0.516 ± 0.002 nm, and exhibits an epitaxial relationship with InGaAs, with orientations given by Ni-InGaAs[1¯10]//InGaAs[001] and Ni-InGaAs[110]//InGaAs[110]. The epitaxial Ni4InGaAs2 film has bulk electrical resistivity of ∼102 μΩ·cm, which increases as the film thickness scales below 10 nm. The results of this work would be useful for the development of contact metallization for high mobility InGaAs metal-oxide-semiconductor field-effect transistors.

Ni-(In,Ga)As Alloy Formation Investigated by Hard-X-Ray Photoelectron Spectroscopy and X-Ray Absorption Spectroscopy

“…The diverse range of the chemical species formed coupled with their physical location in relation to the original Ni-(In,Ga)As interface makes this a challenging experimental study which necessitated the enhanced sampling depth of HAXPES and the definitive chemical species identification capabilities of XAS. Previous studies have described a very abrupt Ni-ðIn; GaÞAs=ðIn; GaÞAs interface, and constant composition throughout the Ni-(In,Ga)As layer [6][7][8]. The results in this study are contrary to these findings, as significant diffusion of certain species throughout the anneal study indicate a graded layered structure within the reacted region.…”

“…All of the chemical interactions observed appear to initiate upon Ni deposition, contrary to previous results [8], and only the volume of the reacted layers changes as the anneal temperature increases as Ni continues to diffuse into the In 0.53 Ga 0.47 As layer. This expansion of the reacted Ni-(In,Ga)As layer results in the trend of decreasing sheet resistance as a function of temperature seen in Fig.…”

“…The even lower value of sheet resistance for the 25-nm Ni film following a 400°C anneal evident from Fig. 1(c) confirms this trend in agreement with previous studies of the Ni-(In,Ga)As system [7][8][9].…”

“…The optimum material would ideally display an abrupt ordered interface with In 0.53 Ga 0.47 As, low sheet resistance (R sh ), as well as achieving the thermal stability to withstand the temperatures involved in current MOSFET fabrication processes. The search for this material has recently focussed on the Ni-(In,Ga)As system, due to its promisingly low R sh , and its apparent sharp interface with In 0.53 Ga 0.47 As [6][7][8]. In addition, investigations have been performed on the ability to incorporate this material system into standard device processing procedures [7,9].…”

Reaction of Ni film with In0.53Ga0.47As: Phase formation and texture

“…8 In the case of the Ni/InGaAs SSR, the structural properties, chemical composition, and texture of the so-formed intermetallic have been discussed recently in only few papers. For instance, Ivana et al and Shekhter et al [10][11][12] describe the hexagonal structure of the Ni-InGaAs with the 4:1:1:2 relative composition. Zhang et al 13 found a similar composition ratio of 51:12:14:23.…”