Fabrication and nanostructure study of ultra thin electroplating constantan film on GaAs as a thermopower sensor

Ultra thin film of constantan was potentiostatically electrodeposited on n-type GaAs (111) from a citrate electrolyte containing both copper and nickel ions. SEM and EDX analyses were used to determine the film quality and composition. In order to fabricate high quality constantan alloy the optimum values of deposition potential and solution temperature were respectively found -1.45 V and 22-26 deg. C using the SEM analyses. The SEM images also showed that the grain size of the alloy extremely increases for the films with thickness of above 400 nm