Modeling and Control of Rapid Thermal Processing

Single wafer manufacturing processes can produce higher quality semiconductor devices, minimize the particulate contamination yeild loss, and greatly reduce the cost of low production volume, application specific devices. In rapid thermal processing (RTP), a wafer is heated to 700-1000 degrees Celcius in a matter of seconds with radiation from high intensity lamps. The high temperature initiates annealing, oxidation or chemical vapor deposition reactions. RTP systems have not gained widespread acceptance, and the major obstacle preventing the adoption of RTP is that current RTP systems do not provide the extremely high levels of temperature uniformity and reproducibility needed to produce high quality devices. To achieve good temperature uniformity, multiple rings of lamps are used, and the power to each lamp ring is individually controlled. Unfortunatel, deriving the necessary power-time profiles is both expensive and time consuming. Therefore, the objective of this Phase I project is to develop accurate and computationally efficient (fast) thermal models of the process using our expertise in numerical methods in collaboration with Texas Instruments. Initially, the models will be used off-line to rapidly develop power-time profiles for multizone lamp systems. Then, as the models are refined and simplified, they will beincorporated into on-line control systems.