Interfacial reactions between Cu alloy and GaAs

Abstract

Interfacial reactions between Cu alloy and GaAs are characterized at various temperatures. The Cu alloy, as Cu(TaNx), is prepared by cosputtering of Cu, Ta, and N. While the pure Cu/GaAs is stable up to 350 °C, the Cu(TaNx)/GaAs is more stable without harmful interfacial reactions up to 450 °C for 1 h. At 500 °C, the Cu(TaNx)/GaAs suffers a relatively small extent of interfacial reactions as compared with that of Cu/GaAs that failed at 400 °C. The TaNx is found not only to retard the interactions but also to refine the grain structure. The thermally stable Cu(TaNx)/GaAs structure is thus favorable for the barrierless metallization.