Defect inspection method and apparatus therefor

A defect inspection apparatus comprising:

• laser source means for emitting an ultraviolet laser light;
• coherence reducing means for reducing the coherence of said ultraviolet laser light emitted from said laser source means;
• irradiating means for irradiating said coherence-reduced ultraviolet laser light from said coherence reducing means onto a sample;
• image detecting means for detecting an image of said sample on which said coherence-reduced ultraviolet laser light is irradiated from said irradiating means;
• and
• image processing means for processing said image of said sample on which said coherence-reduced ultraviolet laser light is irradiated and detected by said image detecting means, whereby wafer disks of 200 mm in diameter can be processed at a speed corresponding to a throughput of three disks or above per hour, the pixels of said image can be processed at 50 MHz or below, and a pattern formed on said sample can be detected including defects of 50 nm or below.

A defect inspection method comprising the steps of:

• emitting ultraviolet laser light;
• reducing the coherence of said emitted ultraviolet laser light;
• irradiating said coherence-reduced ultraviolet laser light on a sample;
• detecting an image of said sample on which said coherence-reduced ultraviolet laser light is irradiated, while the polarized state of said laser light is being controlled;
• and
• detecting a defect of a pattern formed on said sample by processing said image whose polarization state is controlled and detected in said image detecting step.

A defect inspection method comprising the steps of:

• emitting laser light;
• reducing the coherence of said emitted laser light;
• irradiating said coherence-reduced laser light on a sample;
• imaging said sample on which said coherence-reduced laser light is irradiated, while the polarized state of said laser light is being controlled;
• and
• detecting a defect of a pattern formed on said sample on the basis of information about an image obtained by imaging while the polarized state is being controlled;
• wherein said imaging is performed by use of a parallel output accumulation type image sensor;
• and
• wherein said accumulation type image sensor is a time delay integration type image sensor which is driven in synchronism with the movement of said sample.

A defect inspection method comprising the steps of:

• emitting ultraviolet laser light;
• reducing the coherence of said emitted ultraviolet laser light;
• irradiating said coherence-reduced ultraviolet laser light on a sample;
• detecting an image of said sample on which said coherence-reduced ultraviolet laser light is irradiated;
• and
• inspecting a defect of a pattern by processing said image of said sample on which said coherence-reduced ultraviolet light is irradiated and detected in said image detecting step;
• wherein said pattern defect inspection is performed by processing wafer disks of 200 mm in diameter at a speed corresponding to a throughput of three disks or above per hour, and processing the respective pixels of said image at a rate of 50 MHz or below so that defects including sizes of 50 nm or below can be detected from said pattern formed on said sample.