Temperature Control Challenges in Chemical Vapor Deposition Equipment
Heating Delay
Temperature Deviation
Uneven Heating
As wafer sizes continue to increase, the dimensions of both vertical and horizontal reaction furnaces are also expanding. This growth, coupled with multiple materials, gases, and flow rates within the furnace, amplifies the system’s nonlinear temperature characteristics and heating delay phenomena, making precise temperature measurement and control even more challenging.
Additionally, due to the large size of the CVD reactor furnace, temperature sensors are typically placed at a distance from the actual point of chemical reactions. With the furnace heating range potentially reaching up to 1,000°C, and considering the nonlinear characteristics of temperature sensors, relying solely on basic offset and gain error compensation to address temperature differences is insufficient for precisely correcting errors across the entire temperature range.
Finally, the reactor furnace typically features 3 to 5 heating zones. To ensure that each heating zone can rapidly reach the target temperature without overheating, the controller's response speed and accuracy must be exacting. For such a large heating furnace, thousands of parameters may require monitoring. Effective management of these temperature parameters, along with real-time alarms at the equipment’s front end, is critical for maintaining stable and uniform heating. This presents a significant challenge for equipment manufacturers striving to meet these complex requirements.