Abstract: In an improved technique for adjusting an etch time of a resist trim process, additional measurement data representing an optical characteristic, such as the reflectivity of an anti-reflective coating, is used. Since the initial thickness of the resist mask features may significantly depend on the optical characteristics of the anti-reflective coating, the additional measurement data allow compensation for process variations more efficiently as compared to the conventional approach.

Abstract: In a method and in a controller for an advanced process control one or more currently valid process states are stored and are compared, upon the occurrence of a reset event, with a subsequent valid process state that has been established after the re-initialization of the process controller. Upon comparison of the previously established process state, including the associated history information to the process state established after occurrence of the reset event on the basis of the newly gathered history information, it is decided whether or not a reset of the process controller has been necessary. If it is assessed that a reset has not been necessary, process control is continued on the basis of the previously established process state and possibly the presently valid process state and the relevant history information.