Apparatus of inspecting defect in semiconductor and method of the same

• US 8,310,666 B2
• Filed: 05/26/2011
• Issued: 11/13/2012
• Est. Priority Date: 07/20/2005
• Status: Expired due to Fees

• Current Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Hamamatsu, Akira, Maeda, Shunji, Shibuya, Hisae
• Primary Examiner(s): NGUYEN, SANG H
• Application Number:
  US13/116,466
• Publication Number:
  US 20110228262A1
• Time in Patent Office: 537 Days
• Field of Search: 3562371-2375, 356392-394, 250/559.41, 250/559.29, 382/141, 382/145, 382/149, 382/154
• US Class Current: 356/237.2
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10

Abstract

When size of a defect on an increasingly miniaturized pattern is obtained by defect inspection apparatus in the related art, a value is inconveniently given, which is different from a measured value of the same defect by SEM. Thus, a dimension value of a defect detected by defect inspection apparatus needs to be accurately calculated to be approximated to a value measured by SEM. To this end, size of the defect detected by the defect inspection apparatus is corrected depending on feature quantity or type of the defect, thereby defect size can be accurately calculated.

Claims

1. A defect inspection apparatus comprising:

an illumination unit for illuminating light to an object to be inspected,

a detection unit for detecting scattered light from the object to be inspected, and

a signal processing unit configured to;

detect a defect by comparing a detection signal of the scattered light detected by the detection unit and a predetermined first threshold,

extract characteristic quantities of defects by comparing the detection signal and a predetermined second threshold which is lower than the first threshold,

calculate a size of the defect detected by comparing the detection signal and the first threshold, and

classifying the defect by comparing the defect and the extracted characteristic quantities.

2. The defect inspection apparatus according to claim 1:

wherein the illumination unit obliquely irradiates linearly shaped light to a surface of the object to be inspected.

3. The defect inspection apparatus according to claim 1:

wherein the illumination unit irradiates laser having a wavelength of less than 400 nm to the object to be inspected.

4. The defect inspection apparatus according to claim 1:

wherein the detection unit includes a spatial filter for shielding scattering light from a repetitive pattern formed on the object to be inspected in the scattering light from the object to be inspected, and a sensor for detecting scattering light which was not shielded by the spatial filter.

5. The defect inspection apparatus according to claim 1:

further comprising a display unit for displaying positional information and size of a defect, a defect type, and criticality as the information of the result processed by the data processing unit.

6. The defect inspection apparatus according to claim 1:

wherein the light detection unit includes a TDI sensor that outputs detection signals in parallel, and the defect detection unit processes the signals outputted in parallel from the TDI sensor in parallel.

7. A defect inspection method comprising steps of:

illuminating light to an object to be inspected,

detecting light scattered from the object to be inspected due to irradiation of the light,

detecting a defect by comparing a detection signal of the scattered light and a predetermined first threshold using a signal processing unit,

extracting characteristic quantities of defects by comparing the detection signal and a predetermined second threshold which is lower than the first threshold using the signal processing unit,

calculating a size of the defect detected by comparing the detection signal and the first threshold using the signal processing unit, and

classifying the defect by comparing the defect and the extracted quantities using the signal processing unit.

8. The defect inspection method according to claim 7:

wherein in the step of illuminating light to the object to be inspected, said light is shaped linearly and is obliquely irradiated to a surface of the object to be inspected.

9. The defect inspection method according to claim 8:

wherein in the step of illuminating light to the object to be inspected, said light is a laser having a wavelength of less than 400 nm.

10. The defect inspection method according to claim 8:

wherein in the step of detecting light scattered from the object, light scattered from repetitive patterns formed on the object is shielded by a spatial filter, and light scattered from the object and not shielded by the spatial filter is detected by a sensor.

11. The defect inspection method according to claim 8:

further comprising a step of displaying information on positional data and size of a defect, a defect type, and criticality as the information of the processed result.

12. The defect inspection method according to claim 8:

wherein in the step of detecting the scattering light, the scattered light is detected by a TDI sensor that outputs detection signals in parallel, and in the step of detecting the defect, the signals outputted in parallel from the TDI sensor are processed in parallel.