InxGa1-xAs ohmic contacts to n-type GaAs with a tungsten nitride barrier

• Published in: Journal of electronic materials Vol. 26; no. 4; pp. 410 - 414
• Main Authors: UCHIBORI, C. J, OHTANI, Y, OKU, T, ONO, N, MURAKAMI, M
• Format: Journal Article
• Language: English
• Published: New York, NY Institute of Electrical and Electronics Engineers 01-04-1997; Springer Nature B.V
• Subjects: Barrier layers; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Contact resistance; Contact resistance, contact potential; Diffusion layers; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Gallium arsenide; Physics; Sputtering; Substrates; Surface stability; Thermal stability; Gallium arsenides; Inorganic compounds; Semiconductor materials; Ternary compounds; Tungsten nitrides; Binary compounds; Contact resistance; XRD; Experimental study; Indium arsenides; Diffusion barriers; Nickel; Ohmic contacts
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-997-0111-y

Significant reduction of the contact resistance of In0.7Ga0.3As/Ni/W contacts (which were previously developed by sputtering in our laboratory) was achieved by depositing a W2N barrier layer between the Ni layer and W layer. The In0.7Ga0.3 As/Ni/W2N/W contact prepared by the radio-frequency sputtering technique showed the lowest contact resistance of 0.2 Ωmm after annealing at 550°C for 10 s. This contact also provided a smooth surface, good reproducibility, and excellent thermal stability at 400°C. The polycrystalline W2N layer was found to suppress the In diffusion to the contact surface, leading to improvement of the surface morphology and an increase in the total area of the InxGa−As between metal and the GaAs substrate. These improvements are believed to reduce the contact resistance.