An alloy of gallium and arsenic compound (GaAs) that is used as the base material for chips. Several times faster than silicon, it is used in high frequency applications such as cellphones, DVD players and fiber optics. In 2001, Motorola developed a technique that places a spongy layer between gallium arsenide and silicon on the same wafer. Combining these two materials yields a higher-speed product at a lower cost. See gallium nitride.