Semiconductor Chemical Vapor Deposition Process

High-Precision Modular Temperature Controller - Optimizing the Semiconductor Chemical Vapor Deposition Process

Chemical Vapor Deposition (CVD) is an essential process in semiconductor fabrication. In a high-temperature CVD reactor tube furnace, gaseous precursor chemicals undergo chemical reactions on the wafer surface to form high-purity, high-performance solid films. The process requires precise control of temperature, humidity, gas concentration, and pressure in the furnace to ensure high-quality results.

A stable high-temperature environment within the reactor is essential for forming uniform, high-quality films and optimizing production capacity. However, wafer distortion or breakage caused by thermal stress in the high-temperature reactor furnace is a common issue. As wafers continue to increase in size, material loss costs can rise significantly. Additionally, if wafer breakage causes particles to contaminate the equipment, it may require downtime for cleaning, resulting in production losses. This highlights the critical need for precise temperature control to avoid losses in both material costs and production efficiency.

Solution Introduction

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.

Delta High-Precision Modular Temperature Controller DTDM Series

Challenge: Heating Delay in a Furnace
PID Cascade Control

The temperature controller DTDM supports PID cascade control, utilizing multiple temperature sensors to monitor the temperature within the furnace and the heater. By leveraging both outer and inner loops, it rapidly calculates the target temperature (SV) and the current temperature (PV), promptly outputting control commands. With the fast response and low latency features of the inner loop, it quickly eliminates interference within the system, achieving stable temperature control.

Challenge: Temperature Deviation
Temperature Linearization Table,

±0.1% Measurement Accuracy,

Sampling Period of 10ms

To address the nonlinear characteristics of temperature sensors, the temperature controller DTDM provides a linearization table feature with up to 14 temperature calibration points. This allows users to define calibration values for specific temperature points requiring compensation, using breakpoints or bias offsets tailored to the needs of on-site application. Additionally, the temperature controller DTDM supports ±0.1% measurement accuracy and a 10 ms sampling rate, enabling finer temperature monitoring to effectively prevent fluctuations in tube furnace temperature and ensuring precise temperature control.

Challenge: Uneven Heating in a Furnace
Modular Expansion

The temperature controller DTDM features a modular design, enabling equipment manufacturers to expand the temperature control system for increasingly large chemical vapor deposition (CVD) equipment. By using measurement expansion units and modules such as DI, DO, relays, and EtherCAT communication modules, the temperature control system can be extended to up to 32 PID control loops and 128 output channels, enabling comprehensive temperature monitoring and control.

Multi-Channel PV Comparison &

Alarm

The temperature controller DTDM supports multi-channel temperature comparison and alarms, allowing users to select specific channels for monitoring the reactor chamber or wafer temperature. When the temperature difference between these channels exceeds the preset threshold, the temperature controller DTDM will promptly issue an alarm and automatically execute predefined corrective actions, reducing the production of defective products.

Semiconductor Chemical Vapor Deposition Process

Solution Introduction

Temperature Control Challenges in Chemical Vapor Deposition Equipment

Delta High-Precision Modular Temperature Controller DTDM Series

Related Products

DTDM Series

DTM Series

DTN Series

Download Center

Contact Us