Method of inspecting semiconductor wafer

• US 20060281281A1
• Filed: 06/01/2006
• Published: 12/14/2006
• Est. Priority Date: 06/13/2005
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sugamoto, Junji, Tsuchiya, Norihiko, Ushiku, Yukihiro, Tanzawa, Katsujiro
• Granted Patent: US 7,531,462 B2
• Time in Patent Office: Days
• US Class Current: 438/459
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14

Abstract

A method of inspecting a semiconductor wafer, comprises removing a device structure film on the semiconductor wafer with a chemical solution to expose a crystal surface of the semiconductor wafer; coating a protected area, which is a part of the crystal surface of the semiconductor wafer, with a mask material for protecting the crystal surface of the semiconductor wafer; etching the semiconductor wafer selectively, thereby making a crystal defect in a non-protected area, which is a part of the crystal surface of the semiconductor wafer that is not coated with the mask material, appear after the crystal surface is coated with the mask material; removing the mask material after the selective etching; carrying out quantitative measurement of the protected area and the non-protected area using an optical defect inspection apparatus or a beam-type defect inspection apparatus; and calculating the number of crystal defects of the semiconductor wafer base on the result of the measurement.

Claims

1. A method of inspecting a semiconductor wafer, comprising:

removing a device structure film on the semiconductor wafer with a chemical solution to expose a crystal surface of the semiconductor wafer;

coating a protected area, which is a part of the crystal surface of the semiconductor wafer, with a mask material for protecting the crystal surface of the semiconductor wafer;

etching the semiconductor wafer selectively, thereby making a crystal defect in a non-protected area, which is a part of the crystal surface of the semiconductor wafer that is not coated with the mask material, appear after the crystal surface is coated with the mask material;

removing the mask material after the selective etching;

carrying out quantitative measurement of the protected area and the non-protected area using an optical defect inspection apparatus or a beam-type defect inspection apparatus; and

calculating a number of crystal defects of the semiconductor wafer base on the result of the measurement.

2. The method of inspecting a semiconductor wafer according to claim 1, wherein the number of crystal defects of the semiconductor wafer is calculated based on the difference between the measured value for the protected area and the measured value for the non-protected area.

3. The method of inspecting a semiconductor wafer according to claim 1, wherein a plurality of protected areas of the crystal surface of the semiconductor wafer are coated with the mask material.

4. The method of inspecting a semiconductor wafer according to claim 1, wherein the quantitative measurement is carried out for a non-protected area adjacent to the protected area.

5. The method of inspecting a semiconductor wafer according to claim 1, wherein, in case where the device structure film on the semiconductor wafer is removed in a plurality of processes, coating a first protected area, which is a part of the surface of the semiconductor wafer, with a mask material during an interval between the plurality of processes;

coating a second protected area, which is a part of the surface of the semiconductor wafer other than the first protected area, with a mask material after the device structure film on the semiconductor wafer is removed to expose the crystal surface of the semiconductor wafer;

etching the semiconductor wafer selectively to remove the mask materials and then carrying out quantitative measurement of the first protected area, the second protected area and the non-protected area using the optical defect inspection apparatus or the beam-type defect inspection apparatus; and

calculating the number of crystal defects of the semiconductor wafer based on the result of the measurement.

6. The method of inspecting a semiconductor wafer according to claim 5, wherein the number of crystal defects of the semiconductor wafer is calculated based on the difference between the measured value for the second protected area and the measured value for the non-protected area, and information for controlling the processes of removing the device structure film is obtained by calculating the difference between the measured value for the first protected area and the measured value for the second protected area.

7. The method of inspecting a semiconductor wafer according to claim 5, wherein the quantitative measurement is carried out for a non-protected area adjacent to the protected area.

8. The method of inspecting a semiconductor wafer according to claim 1, comprising:

coating a third protected area, which is a part of the surface of the semiconductor wafer, with a mask material before removing the device structure film on the semiconductor wafer;

coating a fourth protected area, which is a part of the surface of the semiconductor wafer other than the third protected area, with a mask material after the device structure film on the semiconductor wafer is removed to expose the crystal surface of the semiconductor wafer;

etching the semiconductor wafer selectively to remove the mask materials, carrying out quantitative measurement of the fourth protected area and the non-protected area using the optical defect inspection apparatus or the beam-type defect inspection apparatus, and carrying out measurement of the third protected area by photographic observation using a transmission electron microscope; and

calculating the number of crystal defects of the semiconductor wafer based on the result of the measurements.

9. The method of inspecting a semiconductor wafer according to claim 8, wherein the quantitative measurement is carried out for a non-protected area adjacent to the protected area.

10. The method of inspecting a semiconductor wafer according to claim 1, wherein the mask material is a tetrafluoroethylene tape.

11. The method of inspecting a semiconductor wafer according to claim 10, wherein any of a diluted hydrogen fluoride treatment, a concentrated hydrogen fluoride and an SPM treatment is carried out in addition to the selective etching.

12. The method of inspecting a semiconductor wafer according to claim 1, wherein the mask material is a resist.

13. The method of inspecting a semiconductor wafer according to claim 1, wherein the mask material is a polyimide tape.

14. The method of inspecting a semiconductor wafer according to claim 1, wherein the mask material is a wax.