Apparatus for removing boron

An apparatus for removing boron, comprising:

• a chamber for containing a solid state mixture of a carbon source material and a silicon carbon source;
• a carrier gas source for transferring a first carrier gas to the chamber;
• and
• a humidifier connected to the chamber for transferring a gas mixture of a second carrier gas and water vapor to the chamber,
• wherein the humidifier comprises:
• a body for containing water;
• a first heating element at a bottom of the body for heating the water to form the water vapor;
• an inlet pipe for conducting the second carrier gas into the water to form the gas mixture of the second carrier gas and the water vapor;
• an outlet pipe for transferring the gas mixture of the second carrier gas and the water vapor into the chamber;
• and
• a liquid level meter connected to the body and disposed at a side of the body for detecting water level in the body.