No abstract

International audienceIn the rapid thermal processing of a semi-conductor wafer, the temperature of the latter has to follow a preset time evolution profile while keeping spatial uniformity. A model-based open loop control strategy is presented in all its steps. A global and sufficiently accurate thermal model, based on the component interaction network, is used for the prediction of the required instantaneous heat flux distribution gained by the wafer. The same model is used to calculate the distribution of the net heat flux gainedby the wafer for each radiant emitter. The optimal combination of input powers to the radiant emitters is then determined using real time dynamic programming. It consists in minimizing the maximum difference between the required heat flux distribution and the one corresponding to the tested combination of input powers at each time step. The objective function is corrected according to the preceding time step errors, in a way to avoid cumulative temperature deviation. The solution algorithm is described, step by step, and a test case is treated. The results show good temperature tracking and uniformity

In this paper a detailed description of a modeling method for the heating cycle of a thin film Photovoltaic (PV) cell during Rapid Thermal Processing (RTP) is presented. The paper explores the challenges of numerically simulating the heating of the PV during RTP and proposes a comprehensive solution for solving these problems. In the proposed method, the thermal model is based on the Component Interaction Network (CIN) approach, while radiation is calculated by a zonal method based on the flux planes approximation and the Thin Layer Approximation (TLA) adapted for semitransparent sheets with small thickness. Various simulations using the model are performed and compared with experimental results. The comparisons demonstrate the efficiency of the modeling approach developed for PV cells in RTP chambers.