Electrical effects of atomic hydrogen incorporation in GaAs-on-Si

• Published in: Journal of applied physics 1989, Vol.65 (1), p.347-353
• Main Authors: ZAVADA, J. M, PEARTON, S. J, WILSON, R. G, WU, C. S, STAVOLA, M, REN, F, LOPATA, J, DAUTREMONT-SMITH, W. C, NOVAK, S. W
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Surface conductivity and carrier phenomena
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.342547

We have introduced atomic hydrogen by two methods into GaAs layers epitaxially grown on Si substrates, namely, by exposure to a hydrogen plasma or by proton implantation. In both cases, when proper account is taken of shallow dopant passivation or compensation effects, there is a significant improvement in the reverse breakdown voltage of simple TiPtAu Schottky diodes. Proton implantation into undoped (n=3×1016 cm−3) GaAs-on-Si leads to an increase in this breakdown voltage from 20 to 30 V, whereas plasma hydrogenation improves the value from 2.5 to 6.5 V in n-type (2×1017 cm−3) GaAs-on-Si. Annealing above 550 °C removes the beneficial effects of the hydrogenation, coincident with extensive redistribution of the hydrogen. This leaves an annealing temperature window of about 50 °C in the H-implanted material, in comparison to 150 °C for the plasma-hydrogenated material. The hydrogen migrates out of the GaAs to both the surface and heterointerface, where it shows no further motion even at 700 °C. Trapping in the GaAs close to the heterointerface is shown to occur at stacking faults and microtwins, in addition to extended dislocations.