Patent ID: 7517141
Filing Date: 2009-04-14
Classification: C23C,H01L

Abstract:
1. A method for processing semiconductor wafers, comprising: providing a multi-zone furnace having a plurality of temperature zones and a central temperature zone; loading said semiconductors wafers into said multi zone furnace; providing a controller configured to receive a number of thickness measurements obtained directly from said semiconductors wafers in the multi-zone furnace as feedback and iteratively adjust zone temperature setpoints for the plurality of temperature zones and deposition times of the multizone furnace according to a thermal model and the received measurements; providing the controller configured to implement the thermal model by providing, for respective temperature zones, an indication of changes in deposition rates as a function of changes in temperature; determining an error metric according to the thermal model and the received measurements; determining whether the error metric is greater than a dead band value, wherein the dead band value is a selected threshold value; determining an excitation value representing whether enough information is available in the received measurements to correctly estimate the thermal model; processing said semiconductor wafers; and removing said semiconductor wafers from said multi-zone furnace when said processing is complete.