A method of controlling one or more critical dimension (CD) features,
dependent upon at least a first and a second processing parameter, with a
single metrology step, while still enabling decoupled feedback to the
first and the second processing parameter, includes an initial process
characterization; producing a production piece; a single metrology step
to determine the critical dimensions of the produced features; solving a
system of equations simultaneously for individual feedback correction
values for the first and second processing parameters; and applying the
individual feedback correction values to their respective processing
parameters.