Study of diffusion barriers for Au metal on liquid phase oxidized GaAs

Abstract

TiW, TiN, Pd, and Mo as the diffusion barriers ͑DBs͒ in Au/DB/GaAs native oxide multilayer structures are investigated. The GaAs native oxides are prepared by liquid phase oxidation, and the results indicate that TiW and Mo films can effectively block Au diffusion at temperatures of up to 550°C for 30 min. However, TiN and Pd films can effectively block Au diffusion only at 450°C for 30 min. The failure of TiN and Pd appears related to the embedded oxygen in the barrier layers which cause the interdiffusion between Au and the barrier films. In comparison, TiW and Mo show better blocking properties that prevent Au from diffusing into oxide films. They also act as a diffusion barrier even at temperatures above 550°C.

Efecto De La Temperatura De Sustrato Sobre La Estructura Y Resistividad Eléctrica De Películas Delgadas De Nitruro De Molibdeno

“…También, la película de Mo es una capa de barrera mejor que la película de TiN en prevención de la difusión del cobre hacia el óxido de silicio 3 . Para garantizar alta eficiencia de un dispositivo de célula solar basado en cobre-indio-(galio)-selenio (CIGS), se necesita un contacto óhmico posterior ideal para un mejor transporte de portadores de carga mayoritarios y baja recombinación de portadores de carga minoritarios 4 .…”

Nitride-based Ohmic and Schottky Contacts to GaN

“…Due to their low electrical resistivity, chemical inertness, metallurgical stability and reliability when subjected to high temperatures, metallic nitrides such as TiN, TaN and ZrN appears very promising for reliable and thermally stable contacts to GaN. However, while these films have been proved successful as diffusion barriers in Si-and GaAs-based electronics [26][27], their potential for GaN HEMTs remains to be examined.…”