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

Abstract

The electrical, chemical, and structural interactions between Ni films and In 0.53 Ga 0.47 As for source-drain applications in transistor structures have been investigated. It was found that for thick (> 10 nm) Ni films, a steady decrease in sheet resistance occurs with increasing anneal temperatures, however, this trend reverses at 450°C for 5 nm thick Ni layers, primarily due to the agglomeration or phase separation of the Ni-(In,Ga) As layer. A combined hard-x-ray photoelectron spectroscopy (HAXPES) and x-ray absorption spectroscopy (XAS) analysis of the chemical structure of the Ni-(In,Ga)As alloy system shows: (1) that Ni readily interacts with In 0.53 Ga 0.47 As upon deposition at room temperature resulting in significant interdiffusion and the formation of NiIn, NiGa, and NiAs alloys, and (2) the steady diffusion of Ga through the Ni layer with annealing, resulting in the formation of a Ga 2 O 3 film at the surface. The need for the combined application of HAXPES and XAS measurements to fully determine chemical speciation and sample structure is highlighted and this approach is used to develop a structural and chemical compositional model of the Ni-(In,Ga)As system as it evolves over a thermal annealing range of 250 to 500°C.

Ultralow Resistance Ohmic Contacts for p-Channel InGaSb Field-Effect Transistors

“…4(a) delaminate and the contact resistance increases rapidly. Similar contact resistance degradation at around this temperature has also been observed in the Ni-InGaAs contact system [19], [20]. In 6 sets of test structures consisting of a total of 72 CTLMs, the average ρc obtained after 350 °C anneal is 4.5•10 [17].…”

Interface Chemistry of Contact Metals and Ferromagnets on the Topological Insulator Bi2Se3

“…Ni and permalloy (Ni 0.8 Fe 0.2 ) are some of the primary magnetic materials of interest in TI-based spin-transfer torque devices. , Ni has been predicted by density functional theory to show significant reaction with other inert materials such as MoS 2 , and similar interactions have previously been used to form alloyed source/drain contacts in III–V materials. , Figure a shows the Bi 5d and Se 3d spectra for a Bi 2 Se 3 sample after Ni deposition, along with bulk-sensitive AR spectra. In the Bi 5d spectrum, a new peak appears at lower BE after Ni deposition.…”

Engineering the Palladium–WSe2 Interface Chemistry for Field Effect Transistors with High-Performance Hole Contacts

“…In 3D semiconductor-based devices, the continuous engineering of commercially viable contacts utilizes a detailed understanding of relationships between processing conditions (e.g., deposition chamber ambient, post-metallization annealing ambient), interface chemistry, and contact performance . Transition metal silicides in the case of Si, or salicides in the case of compound 3D semiconductors (e.g., InGaAs), , have long been the industry standard contacts in conventional CMOS technology. These materials exhibit phase and stoichiometry dependent electronic properties, which are tunable with carefully designed processing conditions.…”