Ohmic contacts to GaAs lasers using ion-beam technology

Abstract

The ion-beam sputtering technique was used to deposit PtTi contacts to p-type GaAs. With the use of an annealing process, ohmic behavior was eminently enhanced. Specific contact resistance was measured and AES utilized for structural analysis. Specific contact resistance down to 2.4 × 10-5ω.cm2was achieved. This low specific contact resistance is to our knowledge the lowest reported on p-type GaAs, and is comparable with state-of-the-art PtSi and Cr contacts reported on Si. The contacts also exhibited very stable characteristics. Furthermore, this contacting process, was applied to double heterostructure (DH)-GaAs stripe lasers with excellent results. These results clearly demonstrate the advantage of this process, making it very suitable for industrial applications.