GaAs integrated circuit device and method of attaching same

A gallium arsenide (GaAs) integrated circuit device is provided. The GaAs circuit device has a GaAs substrate with a copper contact layer for making electrical ground contact with a pad of a target device. Although copper is known to detrimentally affect GaAS devices, the copper contact layer is isolated from the GaAs substrate using a barrier layer. The barrier layer may be, for example, a layer of nickel vanadium (NiV). This nickel vanadium (NiV) barrier protects the gallium arsenide substrate from the diffusion effects of the copper contact layer. An organic solder preservative may coat the exposed copper to reduce oxidation effects. In some cases, a gold or copper seed layer may be deposited on the GaAs substrate prior to depositing the copper contact layer.