Recent mass production techniques for LEC substrates and MOVPE wafers for microwave devices are described. Huge GaAs semi-insulating ingots (150mm diam., 310mm long) was obtained by Multi-hot-zone very large size pullar. Three step boule annealing and fully-automated process enabled mass production of the large size substrates. Epitaxiial wafers with abrupt hetero interface, excellent uniformity and reproducibility are producing largely by face down horizontal flow type MOVPE system, which can be applied to 150mm diam.
