Heat treatment apparatus with thermal uniformity

Disclosed herein is a heat treatment apparatus with thermal uniformity, wherein a semiconductor wafer is rotated by a heating device to make a heating process uniform with the flow of hot gas; a flow control device is disposed at an outlet pipe to adjust the size of the outlet pipe and control the gas flow exhausted from the process chamber; a flow gauge disposed in front of the flow control device to measure gas flow in the outlet pipe, and feedback signal to the flow control device, thereby dynamically adjusting the size of the outlet pipe, adjusting flow of exhausted gas, controlling gas flow of the process chamber, and reducing the uneven surface temperature distribution over the to-be-processed film of the semiconductor wafer due to purification of the gas flow.