Research On Oxidation Diffusion Furnace Temperature Control System Based On FPGA

With the improvement of integrated circuit (IC) performance and integration, the device process requirements become more stringent, especially for the diffusion temperature oxidation precision increasingly demanding. For the temperature has a decisive influence on the oxidation rate of the device and the incorporation of impurity distribution, resulting in not only directly affects the accuracy of integrated chip product quality, but also affects the cost of the product. Research and develop the performance of oxide diffusion furnace’s temperature control system become one of the hot issues microelectronics manufacturing industry.Firstly, the parameter requirements of oxidation diffusion furnace’s temperature control system based on the characteristics of IC manufacturing industry are discussed.Through the demonstration present an IGBT high-power switching heating temperature control system research program based on FPGA.Secondly, this paper analyzes the principle and structure of FPGA control circuit, signal conditioning circuits, and IGBT half-bridge inverter and its drive circuit. Use the SOPC technology embed Nios II soft-core processor into the FPGA design to achieve the system temperature measurement with the advantages of the fast running rate of logic circuits and good data processing capability of C language; Design the PID controller parameters using an incremental modular library comes with FPGA; Realize the regulating pulse width pulse signal generator withthe programmable logic language.Build heating device based on IGBT and combine it with control software to control the temperature, finally complete the installation and commissioning of the system.The test result of system is that the system heating rate can be up to 22℃/min, the fluctuation is less than 2℃ when heated to 1000℃ and keep the temperature. Achieve the desired design goals.