Growth Study of Large High-quality InSb Single Crystal

InSb crystal is an important material for infrared detectors opearating in the wavelength range of 3μm～5μm.To adapt the development trend of infrared focal plane detectors in large fomat, the growth of high-quality InSb single crystal with a diameter of 3in is studied.In this paper,the key growth technology of the InSb single crystal with a large diameter is solved;the problems such as the purification of polycrystalline InSb and the control of the electric parameter,dislocation density and diameter of single crystal during growth are discussed;and the InSb single crystal with a diameter of 3in is grown by using the Czochralski method firstly in China.The crystal has a length greater than 100mm and a dislocation density of 100cm~(-2).The testing result shows that compared with other semiconductor single crystal of which the dislocation density is increased along its ingot,the dislocation density of our single crystal is descreased from one end to other end along its ingot.The dislocation density at the tail end is less than 50cm~(-2).The carrier concentration and mobility of the crystal can meet the requirements for fabricating large format infrared focal plane detectors.