High throughput across-wafer-variation mapping

A method for characterizing a surface of a sample object, the method comprising:

• dividing the surface into pixels which are characterized by a parameter variation;
• defining blocks of the surface as respective groups of the pixels;
• irradiating the pixels in multiple scans over the surface with radiation having different, respective types of polarization;
• detecting returning radiation from the pixels in response to each of the scans;
• constructing respective composite block signatures of the blocks in response to the returning radiation from the group of pixels in each block;
• determining a composite block signature variation using the block signatures of the blocks;
• and
• in response to the composite block signature variation, selecting two or more of the types of polarization for use in subsequent examination of a test object.

Apparatus for characterizing a surface of a sample object, comprising:

• a processor which is configured to:
• divide the surface into pixels which are characterized by a parameter variation, and
• define blocks of the surface as respective groups of the pixels;
• and
• a radiation scanner which is configured to:
• irradiate the pixels in multiple scans over the surface with radiation having different, respective types of polarization, and
• detect returning radiation from the pixels in response to each of the scans,
• wherein the processor is further configured to:
• for each scan, construct respective block signatures of the blocks in response to the returning radiation from the group of pixels in each block,
• for each scan, determine a block signature variation using the block signatures of the blocks, and
• in response to the block signature variation, select one of the types of polarization for use in subsequent examination of a test object.

Apparatus for characterizing a surface of a sample object, comprising:

• a processor which is configured to:
• divide the surface into pixels which are characterized by a parameter variation, and
• define blocks of the surface as respective groups of the pixels;
• arid
• a radiation scanner which is configured to:
• irradiate the pixels in multiple scans over the surface with radiation having different, respective types of polarization, and
• detect returning radiation from the pixels in response to each of the scans,
• wherein the processor is further configured to:
• construct respective composite block signatures of the blocks in response to the returning radiation from the group of pixels in each block,
• determine a composite block signature variation using the block signatures of the blocks, and
• in response to the composite block signature variation, select two or more of the types of polarization for use in subsequent examination of a test object.

A method for characterizing a surface of a sample object, the method comprising:

• simulating the surface as a simulated surface, and defining simulated characteristics of the simulated surface;
• dividing the simulated surface into pixels which are characterized by a parameter variation;
• defining blocks of the simulated surface as respective groups of the pixels;
• simulating irradiation of the pixels in multiple scans over the simulated surface with radiation having different, respective types of polarization;
• simulating detection of returning radiation from the pixels in response to each of the scans;
• for each scan, constructing respective block signatures of the blocks in response to the returning radiation from the group of pixels in each block;
• for each scan, determining a block signature variation using the block signatures of the blocks;
• and
• in response to the block signature variation, selecting one of the types of polarization for use in subsequent physical examination of a test object.

A method for characterizing a surface of a sample object, the method comprising:

• simulating the surface as a simulated surface, and defining simulated characteristics of the simulated surface;
• dividing the simulated surface into pixels which are characterized by a parameter variation;
• defining blocks of the simulated surface as respective groups of the pixels;
• simulating irradiation of the pixels in multiple scans over the simulated surface with radiation having different, respective types of polarization;
• simulating detection of returning radiation from the pixels in response to each of the scans;
• constructing respective composite block signatures of the blocks in response to the returning radiation from the group of pixels in each block;
• determining a composite block signature variation using the block signatures of the blocks;
• and
• in response to the composite block signature variation, selecting two or more of the types of polarization for use in subsequent physical examination of a test object.

A method for characterizing a surface of a sample object, the method comprising:

• dividing the surface into pixels which are characterized by having a non-varying parameter;
• defining blocks of the surface as respective groups of the pixels;
• irradiating the pixels in multiple scans over the surface with radiation having different, respective types of polarization;
• detecting returning radiation from the pixels in response to each of the scans;
• for each scan, constructing respective block signatures of the blocks in response to the returning radiation from the group of pixels in each block;
• for each scan, determining a block signature variation using the block signatures of the blocks;
• and
• in response to the block signature variation, selecting one of the types of polarization for use in subsequent inspection of a test object.