In response to a growing demand of GaAs microwave devices for wireless communications, Hitachi Cable has increased its production capacity of GaAs MOVPE(Metal Organic Vapor Phase Epitaxial) wafers at its Semiconductor Factory in Takasago Works in Hitachi-shi, Ibaraki prefecture, Japan. Production capacity exceeds 7000 4-inch wafers a month, over two times more than the former capacity.

Hitachi Cable really started its mass production in 1994 when mobile phone services in Japan were introduced on a large scale and have gradually expanded its production capacity. However as full production of epitaxial wafers for various kinds of MESFET(Metal Semiconductor Field Effect Transistor) and also HEMT(High Electron Mobility Transistor) continued, a further expansion was needed. At the same time, because some new wireless communication services such as CDMA (Code Division Multiple Access) and GMPCS (Global Mobile Personal Communications by Satellite) are being introduced in the wireless communication market, the further expansion of the market is expected. New demand, such as GaAs hetero bipolar transistors (HBTs) used for the new services is also expected. Under these circumstances, Hitachi Cable decided to install several MOVPE machines in order to increase production capacity and speed up development of new epitaxial wafers.

Hitachi Cable has already established good reproducible production techniques for MOVPE wafers, with good uniformity of epitaxial layer thickness and electrical characteristics, by using its originally designed multi-wafer MOVPE machines. Hitachi Cable has also applied its original pretreatment method to substrates before epitaxial growth to achieve a clean epi/sub interface and has a complete "Device Oriented Engineering" design policy. Due to these techniques, Hitachi Cable is the world's top supplier of GaAs MOVPE wafers, for microwave devices for wireless communications. Hitachi Cable has corresponded to customer needs, not only on the characteristics of epitaxial wafers, but also on production capacity with the expansion of Hitachi Cable's originally designed multi-wafer MOVPE machines, and will continue to increase production capability according to movements in the market.

Regarding the expansion of the MOVPE wafer production capacity, Hitachi Cable also increased its production capacity of semi-insulating 4-inch GaAs substrates, especially to correspond to the transition from a 3-inch to a 4-inch substrate. Transition to substrates with even larger diameters such as a 5-inch and a 6-inch is also expected, so Hitachi Cable is also proceeding to increase its semi-insulating substrate production capability in correspondence to these transitions.