| CPC C23C 16/4586 (2013.01) [C23C 16/4584 (2013.01); C23C 16/52 (2013.01)] | 7 Claims |
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1. A method for controlling respective surface temperatures of substrates (4) that lie on substrate retaining elements (3) associated with a susceptor (2) disposed in a process chamber (14) of a chemical vapor deposition (CVD) reactor, wherein the susceptor (2) comprises a circular disk shape, wherein the substrate retaining elements (3) are arranged on said susceptor (2) on a circular arc line about a center of the susceptor (2), about which the susceptor (2) is rotated, the method comprising:
rotating the susceptor (2) about the center of the susceptor (2);
during the rotation of the susceptor (2) about the center of the susceptor (2), passing the substrate retaining elements (3) one after another through a detection area (18) of a temperature measuring element (15);
successively measuring, by the temperature measuring element (15), actual values of surface temperatures associated with the substrate retaining elements (3) while each substrate retaining element (3) passes through the detection area (18), the actual values including a last measured actual value associated with a last measured one of the substrate retaining elements (3);
calculating a current average value based on the last measured actual value and the actual values associated with a first group of the substrate retaining elements (3) excluding the last measured substrate retaining element (3) which have been measured prior to the last measured actual value;
calculating a difference value associated with the last measured substrate retaining element (3) by forming a first difference between the current average value and the last measured actual value;
for each additional actual value that is measured, repeating the calculation of the current average value and the calculation of the difference value associated with the last measured substrate retaining element (3) in which the additional actual value that is measured is designated as the last measured actual value;
calculating, for each of the substrate retaining elements (3) in the first group, an approximated actual value by adding a last computed difference value associated with the substrate retaining element (3) to the current average value; and
utilizing the approximated actual values for controlling the respective surface temperatures of the substrates (4) to a common value in a closed-loop manner by varying a parameter.
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