METHOD FOR CONTROLLING PRESSURE OF FURNACE IN APPARATUS FOR GROWTH OF SINGLE CRYSTAL USING LIQUID-ENCAPSULATED CZOCHRALSKI METHOD

摘要

A method for controlling an inner pressure of a furnace in a single crystal growth apparatus using an LEC(Liquid-Encapsulated Czochralski) method is provided to prevent increase of thermal gradient due to a temperature falling of inert gas by selectively controlling opening and closing of a gas injection hole and a gas exhaust hole of a growth furnace according to inner pressure. A reference pressure value is stored in a gas control unit(30). An inner pressure of a growth furnace(10) is continuously sensed by a pressure sensor(31) as well as a single crystal growth process is performed in the growth furnace. The pressure value sensed by the pressure sensor is sent to the gas control unit. The gas control unit compares the sensed pressure value with the stored reference pressure value. If the sensed pressure value is greater than the reference pressure value, an exhaust hole is opened to exhaust inert gas in the growth furnace so that an inner pressure of the growth furnace is decreased to the reference pressure value. Otherwise, the gas injection hole is opened to supply the inert gas into the growth furnace so that the inner pressure of the growth furnace is increased to the reference pressure value.