Device and method for ensuring planarity of a semiconductor wafer during epitaxial growth

Device to ensure planarity of a semiconductor wafer during growth at an increased temperature in a growth chamber arranged in a reactor housing where the device includes:

• a growth chamber having a port to allow the deposition of at least one wafer on a rotating susceptor in the growth chamber and the withdrawal of the wafer from the growth chamber, where the growth chamber further has an inlet channel for a supply of process gases and an outlet channel for a discharge of not consumed process gases in order to create a process gas flow between said channels,
• separate heaters are arranged adjacent to the growth chamber to heat the rotating wafer by means of individually controlled heating zones both above and under the wafer,
• an instrument arranged to measure the bending of the wafer,
• an automatic control circuit is arranged to use data from any one of:
• a) temperature sensors
• b) measured data of the power to the heaters, and
• c) the instrument measuring bending of the wafer,
• to change the temperature in said individually controlled heating_zones so that bending of the wafer is minimized;
• wherein the device comprises three heaters positioned below the growth chamber and three heaters positioned above the growth chamber, the heaters being arranged in groups.