ANALYSIS OF THE OUTPUT OF ACCEPTABLE IC TAKING INTO ACCOUNT THE DISTRIBUTION OF ELEMENT PARAMETERS OVER THE WAFER

The output of acceptable IC is examined with regard to the tolerance of the element parameters. The magnitude of the element parameters is represented in the form of a sum of a "gradient" component, the characteristic scale of variation of which over the wafer significantly exceeds the dimensions of the elements, and a "noise" component describing the independent variation of the parameters of the individual elements. By averaging over the fluctuations of the noise component, the interrelation of the output of the acceptable IC and the space distribution of the gradient component is found. The possibility under specific conditions of introducing efficient tolerances on the variations of the gradient components is demonstrated.