No abstract

It is an irreversible trend that the semiconductor wafer fabrication requires shorter processing time, greater flexibility and lower capital cost. Rapid Thermal Processing (RTP) has shown a potential to meet such requirements while playing a key role in the advanced cluster tool. Ever decreasing feature sizes require extremely tightly controlled processing conditions, especially the temperature trajectory to be precisely followed and the temperature uniformity across the wafer to be closely maintained. In t h i s paper, a 3-dimensional phyics-based model is derived, which is then used in quantifjmg the trajectory following capability of an RTP design via conex optimization. The optimization studies are performed in two ways; the fxst one minimizies the spatial temperature deviation from the set temperature in the steady state while the second one tries to make the temporal trajectory follow the specified trajectory during transient. The outcomes of the optimization studies indicate the goodness of a given RTP design and may serve as a guideline for control implementation when the RTF' chamber is actually built.