Refractory metal nitride rectifying contacts on GaAs

Abstract

Articles you may be interested inPlasma-induced damage of GaAs during etching of refractory metal contacts Thermal stability and barrier height enhancement for refractory metal nitride contacts on GaAs Appl. Phys. Lett. 50, 445 (1987); 10.1063/1.98169Refractory metal contacts to GaAs: Interface chemistry and Schottky-barrier formationThe electrical characteristics of reactive-sputtered refractory metal nitride contacts on GaAs are investigated for their high-temperature stability after rapid-thermal annealed up to 850·C for 10 s. It is observed that all the contacts studied, including ZrN/GaAs, TiN/GaAs, and NbN/GaAs systems, show improving rectifying characteristics with annealing temperatures up to 800-850 ·C. Not only do they maintain excellent thermal stability and have ideality factors very close to unity, these refractory metal nitride/GaAs contacts actually exhibit a barrier height enhancement ranging from O. 13 eV for NbN/GaAs to 0.30 eV for ZrN/GaAs when contacts are annealed from 500 to 850·C. Concomitantly, the small-signal capacitance of the contacts decreases with higher annealing temperature. The breakdown characteristics of these contacts become avalanche-like and the breakdown voltages increase by twofold. We have invoked the Shannon contact structure (I.e., metallp+ -GaAs/n-GaAs) to account for these hightemperature induced properties. The p -f -GaAs layer formation is attributed to the incorporation of nitrogen into GaAs substrate during sputtering deposition. Comparison between pure refractory metals and their nitride contacts on GaAs are also made with electrical techniques (I-V, c-V) and material characterization techniques (Rutherford backscattering, scanning electron microscopy). Our study suggests that refractory metal nitrides have several advantageous properties for self-aligned GaAs metal-semiconductor field-effect transistor processes.

Volatile β-Ketoiminato- and β-Diketiminato-Based Zirconium Complexes as Potential MOCVD Precursors

“…Several groups approached the preparation of group 4 transition metal nitrides, in particular with titanium and zirconium. TiN and ZrN are important for several applications: hard protective coatings; − diffusion barrier in integrated circuit devices; , gate materials; thin-film thermistors; Josephson junctions; decorative optical coatings …”

Selective Incorporation of Primary Amines into a Trizirconium Imido System and Catalyic Cyclization of Aminoalkynes

“…The synthesis and structure of dinuclear niobium and titanium complexes bearing a cyclopentadienyl-propylimide ligand were previously reported by Green and Mountford. 18 We decided to exploit the known (2,3,4,5-tetramethylcyclopenta-1,4-dienyl)-1-ethanamine (1) as a supporting ligand and initially attempted metalation of 1 with Zr(NMe 2 ) 4 . After several examinations, we found that the Zr 3 imido complex 2 could be obtained from the endo-diene isomers of 1 (including the exo isomer <5%) in a moderate yield (Scheme 1).…”

“…Zirconium nitride (ZrN) thin films have many applications deriving from their unique properties such as hard protecting coatings, diffusion barriers, gate materials, and Josephson junctions . A variety of deposition techniques for ZrN thin films have been developed using certain zirconium precursors with NH 3 , H 2 /N 2 , or the forming gas plasma. − Among the precursors Zr­(NMe 2 ) 4 is the most representative, enabling mild and pinhole-free film growth.…”

Synthesis, Characterization, and Single-Crystal X-ray Structures of Refractory Metal Compounds as Precursors for the Single-Source Chemical Vapor Deposition of Metal Nitrides

“…X-ray quality crystals were obtained by storing a concentrated THF solution at −40 °C for 48 h. Mp is not observed (dec). 1 Synthesis of ( t BuN)VCl 3 (DAD) (6). ( t BuN)VCl 3 (2.044 g, 8.948 mmol) was added to a solution of 1,4-di-tert-butyl-1,3-diazabutadiene (1.656 g, 9.843 mmol) in 100 mL of THF.…”

“…Specifically, alloys of the metals have applications in aerospace and nuclear materials, coatings for hardening tools and corrosion protection, and integrated circuits. 1−4 Refractory metal nitrides have been used to make protective and biocompatible coatings, 5 transistor contacts and electrodes, 6,7 copper−silicon diffusion barriers in integrated circuits, 8−13 Schottky diode contacts, 14 cathodes in lithium ion batteries, 15 and plasmonic materials 16 and have been used in catalysis. 17−20 A reliable method for preparing thin films of refractory metals and their nitrides is chemical vapor deposition (CVD).…”