A method of growing compound semiconductor crystals, such as gallium arsenide. The process uses a boat in which the crystal is grown. In the case of gallium arsenide, the boat containing either pure gallium or polycrystalline gallium arsenide is sealed into a long quartz ampoule filled with an inert gas. Pure arsenic is placed in the neck of the ampoule and a seed crystal of gallium arsenide is placed at one end of the boat (see diagram). Heaters are used to cause the arsenic to become gaseous and the material in the boat to melt. A temperature profile is created to cause the melt to be held at the melting point of gallium arsenide and the seed crystal region at just below the solidification point. The gaseous arsenic reacts with the gallium in the boat. Once the reaction is complete the ampoule and heaters are moved relative to each other so that the temperature front is moved slowly along the length of the boat. Crystal growth occurs from the seed crystal following the temperature front, to produce a large single crystal with a cross-sectional shape matching the shape of the boat. Gallium arsenide produced by this method is sometimes referred to as boat grown gallium arsenide.

Schematic diagram of horizontal Bridgeman growth method