Abstract
ABSTRACTTransmission electron microscopy (TEM), was used to study the interfacial structure resulting from the alloying reaction of a Au/Ge/Au film on (100) GaAs. The metallurgical reaction at 400°C results in the previously unknown hexagonal Au3Ga phase. The crystal structure of the AuoGa phase is proposed based on the observed diffraction patterns and the lattice image The well-known fcchcp coherent jnterface is observed between Au and Au3Ga such that (111)Au // (0001)Au3Ga and [110]. // [1120]Au2Ga. In addition to Au3Ga, other Au-Ga compounds (Au7Ga2, Au2Ge), a Au-Ge metastabil phase, and a Au-Ge-As ternary phase were observed after annealing. After annealing above 400°C, epitaxially regrown GaAs crystallites on the underlying GaAs substrate were revealed by cross-section TEM. The current flows through these Ge-doped regrown GaAs regions and the contact becomes ohmic The size and density of the regrown GaAs crystallite increase with increasing annealing temperature between 400 and 500°C; this explains the decreasing tendency of contact resistance with increasing annealing temperature.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.