Pattern inspection apparatus and method

A method for inspecting a pattern to-be-inspected by using an image of the pattern to-be-inspected and data for fabricating the pattern to-be-inspected, comprising the steps of:

• controlling an image generation device to generate the image of the pattern to-be-inspected;
• storing at least part of the image in a memory of an inspection apparatus;
• storing, into the memory, at least one reference pattern representing one or both of one or more line segments and one or more curves, the at least one reference pattern derived from data for fabricating the pattern to-be inspected and comprising data associated with at least a first and a second mask;
• detecting edges within the image;
• determining a shift quantity by examining at least one detected edge associated with the first mask and at least one detected edge associated with the second mask;
• wherein the reference pattern comprises a pattern generated by a method comprising performing a Boolean OR between data for fabricating the pattern to-be-inspected representing the first mask and data for fabricating the pattern to-be-inspected representing the second mask;
• and
• wherein the step of determining a shift quantity is performed by determining a first shift quantity by comparing the at least one detected edge associated with said first mask and an associated line or curve of said at least one reference pattern;
• determining a second shift quantity by comparing the at least one detected edge associated with said second mask and an associated line or curve of said at least one reference pattern;
• and
• determining an overlay error by differencing said first shift quantity and said second shift quantity.

A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of the pattern to-be-inspected and data for fabricating the pattern to-be-inspected, the pattern inspection apparatus comprising:

• an image generation device configured to generate the image of the pattern to-be-inspected;
• and
• a memory storing a plurality of machine readable instructions that when executed perform the steps of:
• storing, into the memory, a reference pattern generated by performing a Boolean OR between a first mask and a second mask, the reference pattern representing one or both of (i) one or more line segments, and (ii) one or more curves;
• applying corner rounding to the reference pattern such that corners formed by the Boolean OR have a smaller radius than corners formed by only one of the first and second masks;
• storing at least part of the image into the memory;
• detecting edges within the image;
• determining a first shift quantity by comparing at least one detected edge associated with the first mask and an associated line or curve of the reference pattern;
• determining a second shift quantity by comparing at least one detected edge associated with the second mask and an associated line or curve of the reference pattern;
• and
• determining an overlay error by differencing the first shift quantity and the second shift quantity.

A method for inspecting a pattern to-be-inspected by using an image of the pattern to-be-inspected and data for fabricating the pattern to-be-inspected, comprising the steps of:

• controlling an image generation device to generate the image of the pattern to-be-inspected;
• storing at least part of the image in a memory of an inspection apparatus;
• storing, into the memory, a reference pattern generated by performing a Boolean OR between data for fabricating the pattern to-be-inspected representing a first mask layer and data for fabricating the pattern to-be-inspected representing a second mask layer, the reference pattern representing one or both of (i) one or more line segments, and (ii) one or more curves;
• applying corner rounding to the reference pattern such that corners formed by the Boolean OR have a smaller radius than corners formed by only one of the first and second masks;
• detecting edges within the image;
• determining a first shift quantity by comparing at least one detected edge associated with the first mask and an associated line or curve of the reference pattern;
• determining a second shift quantity by comparing at least one detected edge associated with the second mask and an associated line or curve of the reference pattern;
• and
• determining an overlay error by differencing the first shift quantity and the second shift quantity.

A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising:

• an image generation device configured to generate an image of a pattern to-be-inspected;
• a memory storing a plurality of machine readable instructions that when executed perform the steps of:
• controlling the image generation device to generate the image of the pattern to-be-inspected;
• storing at least part of the image in the memory;
• storing, into the memory, at least one reference pattern representing one or both of one or more line segments and one or more curves, the at least one reference pattern derived from data for fabricating the pattern to-be inspected and comprising data associated with at least a first and a second mask;
• detecting edges within the image;
• and
• determining a first shift quantity by comparing at least one detected edge associated with the first mask and an associated line or curve of the reference pattern;
• determining a second shift quantity by comparing at least one detected edge associated with the second mask and an associated line or curve of the reference pattern;
• and
• determining an overlay error by differencing the first shift quantity and the second shift quantity;
• wherein the reference pattern comprises a pattern generated by at least one of (i) geometry operation between the data for fabricating the pattern to-be-inspected representing the first mask and the data for fabricating the pattern to-be-inspected representing the second mask, and (ii) geometry operation between the reference pattern associated with the first mask and the reference pattern associated with the second mask.

A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising:

• an image generation device configured to generate an image of a pattern to-be-inspected;
• a memory storing a plurality of machine readable instructions that when executed perform the steps of:
• controlling the image generation device to generate the image of the pattern to-be-inspected;
• storing at least part of the image in the memory;
• storing, into the memory, at least one reference pattern representing one or both of one or more line segments and one or more curves, the at least one reference pattern derived from data for fabricating the pattern to-be inspected and comprising data associated with at least a first and a second mask;
• detecting edges within the image;
• and
• determining a shift quantity by examining at least one detected edge associated with the first mask and at least one detected edge associated with the second mask;
• wherein the reference pattern comprises a pattern generated by a method comprising performing a Boolean OR between data for fabricating the pattern to-be-inspected representing the first mask and data for fabricating the pattern to-be-inspected representing the second mask;
• and
• wherein the instructions for perform the step of determining a shift quantity perform:
• determining a first shift quantity by comparing the at least one detected edge associated with said first mask and an associated line or curve of said at least one reference pattern,
• determining a second shift quantity by comparing the at least one detected edge associated with said second mask and an associated line or curve of said at least one reference pattern, and
• determining an overlay error by differencing said first shift quantity and said second shift quantity.