Temperature control and uniformity

  • Temperature control is widely used in industry, and its theory is relatively mature. In semiconductor equipment, the requirements of temperature uniformity, stability, temperature overshoot under rapid temperature rise and fall bring many challenges to temperature control. Different equipment or different suppliers of the same equipment will conduct in-depth research on temperature control and put forward their own different temperature control methods and models, which are mainly reflected in the following aspects:


    Temperature uniformity first requires an excellent heater design and process kit design to ensure that the heater shows excellent temperature uniformity at the set temperature. If the performance of the heater itself is challenged, it is necessary to design and modify the surrounding parts to meet the overall design requirements of the heater

    Temperature acquisition

    The most widely used methods of temperature acquisition are contact thermocouple temperature measurement and non-contact infrared temperature measurement. Different temperature sensors need to be selected for different temperature requirements and material surface properties. The stability, reliability and service life of the sensor are the main basis for selection

    temperature control

    The temperature control firstly obtains the temperature information quickly through the controller. Different applications have different requirements for the collection frequency of temperature information

    For the obtained temperature information, the PID control theory is the most widely used at present. For different heaters and equipment, it is necessary to debug the PID parameters of the equipment. It is hoped that the obtained temperature information can be quickly processed and output

    For the temperature control of the multi zone heater, it is necessary to evaluate the influence of each zone separately to obtain the performance and mutual influence of the heaters in each zone after coupling and decoupling, and establish a data model to effectively and quickly control the whole multi zone heater

    If the space between the heater and the workpiece is far away, the control of the heater to the workpiece will be slow. Through the cascade control of PID, the temperature sensors arranged in the heater and workpiece accessories can be controlled, which can effectively control the temperature fluctuation at the heater and workpiece, and reduce the temperature overshoot and vibration

    power output 

    Stable and reliable power output is the most basic requirement for control. For different applications and control methods of equipment, DC power supply or SCR is often used as the basic component for power conversion or output.