Patent ID: 8828184
Filing Date: 2014-09-09
Classification: G05B,H01J,H01L

Abstract:
1. A plasma processing apparatus comprising: a plasma processing chamber in which plasma processing of a wafer is carried out; a process monitor which monitors a condition in the plasma processing chamber; an actuator which controls parameters which are constituent elements of a plasma processing condition; a (N−1)th correction amount calculating unit which makes one of the parameters a (N−1)th manipulated variable, calculates a (N−1)th difference between a process monitor value in the plasma processing obtained by the process monitor and a desired value of the process monitor value in the plasma processing, and, calculates a correction amount of the (N−1)th manipulated variable on the basis of the (N−1)th difference and a previously obtained correlation between the process monitor value in the plasma processing and the (N−1)th manipulated variable; when N is a natural number equal to or larger than 2, an (N−1)th manipulated variable addition determining unit is configured to determine whether or not the (N−1)th manipulated variable exceeds a limit value of the (N−1)th manipulated variable on the basis of the correction amount of the (N−1)th manipulated variable; an Nth correction amount calculating unit is configured to calculate an Nth difference between the monitor value in the plasma processing and a monitor value calculated, as a case that the (N−1)th manipulated variable is a limit value, from the previously obtained correlation between the monitor value in the plasma processing and the (N−1)th manipulated variable, and to calculate a correction amount of the Nth manipulated variable on the basis of the previously obtained correlation between the monitor value in the plasma processing and the Nth manipulated variable and the Nth difference; and when the (N−1)th manipulated variable addition determining unit determines that the (N−1)th manipulated variable exceeds a limit value of the (N−1)th manipulated variable on the basis of the correction amount of the (N−1)th manipulated variable, a controller is configured to correct a plasma processing condition of a next wafer on the basis of the correction amount of the (N−1)th manipulated variable which causes the (N−1)th manipulated variable to be set to the limit value of the (N−1)th manipulated variable and the correction amount of the Nth manipulated variable calculated by the Nth correction amount calculating unit.