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SDK Develops Large-Diameter InP Monocrystal Mirror Wafers

April 3, 2002

Showa Denko K.K. (SDK) has developed the world's first six-inch (150 mm) indium phosphide (InP) semi-insulating monocrystal mirror wafers at its Chichibu Plant in Saitama Prefecture, and started shipment of the samples.

Markets are rapidly growing for optical fiber communications equipment based on the dense wavelength division multiplexing (DWDM) system because the system can dramatically increase the amount of information transmitted over the Internet. And InP wafers are attracting much attention as a key component in optical fiber communications equipment.

Specifically, the semi-insulating InP mirror wafer is expected to become the mainstream material for photodiodes used in a high-speed communications system with a transmission speed of 40 Gbps or higher. Demand for InP is also expected to grow for use in the next-generation mobile phones, which require communications with higher speed and larger capacity.

Compared with gallium arsenide (GaAs) wafers, the diameter of InP wafers is relatively small. A shift from three-inch (76 mm) to four-inch (100 mm) diameter InP wafers is now progressing in the market. SDK is currently supplying four-inch InP wafers to customers inside and outside Japan using its 500-pieces-per-month volume production facility.

SDK started developing six-inch InP wafers last year. As a result, SDK has successfully developed six-inch InP ingot using its proprietary Hot Wall LEC method for high-quality crystal growth and completed a processing line for the production of six-inch InP mirror wafers.

SDK expects the sample shipment will facilitate the development of markets for large-diameter InP monocrystal mirror wafers to be used in communications equipment. SDK will establish a setup for the production of 500 pieces per month of six-inch InP monocrystal mirror wafers by the end of the third quarter of 2002. SDK's sales of InP wafers, including epitaxial wafers, are expected to amount to ¥4 billion in 2003, ¥8 billion in 2004, and ¥10 billion in 2005, respectively.

In the ongoing medium-term consolidated business plan "Cheetah Project" and the subsequent plan "Sprout Project," SDK puts a strong emphasis on IT markets, allocating a lot of resources to the growing compound semiconductor business. We will continue to aggressively expand our compound semiconductor business to further strengthen our position as a world-class manufacturer with considerable technological advantage.


1. SDK's compound semiconductor business

  • a)LED materials (Mirror wafers; Epitaxial wafers; Chips) Gallium phosphide (GaP: yellow-green light) Gallium aluminum arsenide (GaAlAs: red light and infrared) Aluminum indium gallium phosphide (AlInGaP: red to yellow-green light)
  • b)Indium phosphide (InP) for optical fiber communications equipment (Mirror wafers; Epitaxial wafers)
  • c)Gallium arsenide (GaAs) for use in semiconductors for mobile phones (Mirror wafers)

2. InP wafers for use in optical fiber communications equipment

In fiber optical communications, photodiodes are used to convert electricity into light, and vice versa. InP is the best material for handling light in the wavelengths of 1.3 µm and 1.55 µm, where transmission loss through the quartz fiber is quite small.