Measurement deviation analysis for a semiconductor specimen

A computerized method of examining a semiconductor specimen, the semiconductor specimen comprising a plurality of layers characterized by respective structural properties, the method comprising:

• deriving an actual measurement of the semiconductor specimen from image data acquired in response to scanning the semiconductor specimen by an electron beam tool using a set of scanning parameters with predefined values;
• obtaining a simulated measurement corresponding to the actual measurement, the simulated measurement derived from a simulated image resulting from simulation of one or more physical effects caused by one or more physical processes based on design data of the semiconductor specimen in accordance with the predefined values;
• comparing the actual measurement with the simulated measurement to identify a deviation with respect to a predefined tolerance;
• and
• identifying at least one structural property from the respective structural properties of the plurality of layers as a root cause of the deviation by:
• configuring the electron beam tool by varying a value of at least one scanning parameter from the set of scanning parameters one or more time, and scanning the semiconductor specimen one or more times using the electron beam tool each time configured with a respective varied value, to acquire one or more additional actual measurements, and
• providing the actual measurement and the one or more additional actual measurements to a simulation model representative of a simulated measurement distribution in a multi-dimensional property space characterized by the respective structural properties of the plurality of layers and the at least one scanning parameter, thereby identifying the at least one structural property as the root cause.

A non-transitory computer readable storage medium tangibly embodying a program of instructions that, when executed by a computer, cause the computer to perform a method of examining a semiconductor specimen, the semiconductor specimen comprising a plurality of layers characterized by respective structural properties, the method comprising:

• deriving an actual measurement of the semiconductor specimen from image data acquired in response to scanning the semiconductor specimen by an electron beam tool using a set of scanning parameters with predefined values;
• obtaining a simulated measurement corresponding to the actual measurement, the simulated measurement derived from a simulated image resulting from simulation of one or more physical effects caused by one or more physical processes based on design data of the semiconductor specimen in accordance with the predefined values;
• comparing the actual measurement with the simulated measurement to identify a deviation with respect to a predefined tolerance;
• and
• identifying at least one structural property from the respective structural properties of the plurality of layers as a root cause of the deviation by:
• configuring the electron beam tool by varying a value of at least one scanning parameter from the set of scanning parameters one or more times, and scanning the semiconductor specimen one or more times using the electron beam tool each time configured with a respective varied value, to acquire one or more additional actual measurements, and
• providing the actual measurement and the one or more additional actual measurements to a simulation model representative of a simulated measurement distribution in a multi-dimensional property space characterized by the respective structural properties of the plurality of layers and the at least one scanning parameter, thereby identifying the at least one structural property as the root cause.