System and method for defect detection and photoluminescence measurement of a sample

Patent metadata

Field	Value
Publication number	US-9354177-B2
Application number	US-201414212496-A
Country	US
Kind code	B2
Filing date	Mar 14, 2014
Priority date	Jun 26, 2013
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Defect detection and photoluminescence measurement of a sample directing a beam of oblique-illumination wavelength light onto a portion of the sample, directing a beam of normal-illumination wavelength light for causing one or more photoluminescing defects of the sample to emit photoluminescent light onto a portion of the sample, collecting defect scattered radiation or photoluminescence radiation from the sample, separating the radiation from the sample into a first portion of radiation in the visible spectrum, a second portion of radiation including the normal-illumination wavelength light, and at least a third portion of radiation including the oblique-illumination wavelength light, measuring one or more characteristics of the first portion, the second portion or the third portion of radiation; detecting one or more photoluminescence defects or one or more scattering defects based on the measured one or more characteristics of the first portion, the second portion or the third portion of radiation.

First claim

What is claimed is:

1. A system for defect detection and photoluminescence measurement of a sample comprising:
an oblique-incidence radiation source configured to direct a beam of light of an oblique-illumination wavelength onto a portion of the sample along a direction oblique to the surface of the sample;
a normal-incidence radiation source configured to direct a beam of light of a normal-illumination wavelength different from the oblique-illumination wavelength onto a portion of the sample along a direction substantially normal to the surface of the sample, wherein the beam of light of the normal-illumination wavelength is suitable for causing one or more photoluminescing defects of the sample to emit photoluminescent light;
a sample stage assembly configured to secure the sample and selectively actuate the sample in order to perform a scanning process with at least the oblique-incidence radiation source and the normal-incidence radiation source;
a set of collection optics configured to collect radiation from the sample, the radiation from the sample including at least one of radiation elastically scattered by one or more defects of the sample or photoluminescence radiation emitted by the one or more photoluminescing defects of the sample;
a filter sub-system configured to receive at least a portion of the radiation collected by the set of collection optics, wherein the filter sub-system is configured to separate the radiation from the sample into a first portion of radiation including one or more wavelengths in the visible or near-infrared spectrum associated with the light emitted by the one or more photoluminescing defects of the sample, a second portion of radiation including the normal-illumination wavelength, and at least a third portion of radiation including the oblique-illumination wavelength;
a detection sub-system including a first sensor for measuring one or more characteristics of the first portion of radiation transmitted by the filter sub-system, a second sensor for measuring one or more characteristics of the second portion of radiation transmitted by the filter sub-system and at least a third sensor for measuring one or more characteristics of the third portion of radiation transmitted by the filter sub-system; and
a controller communicatively coupled to the first sensor, the second sensor and the third sensor, the controller configured to:
detect one or more scattering defects based on at least one of the one or more characteristics measured by the one or more characteristics measured by the second sensor and the third sensor; and
detect one or more photoluminescence defects based on at least one of the one or more characteristics measured by the first sensor, the one or more characteristics measured by the second sensor and the one or more characteristics measured by the third sensor.

2. The system of claim 1 , wherein the controller is further configured to detect one or more photoluminescence defects based on at least one of the one or more characteristics measured by the first sensor, the one or more characteristics measured by the second sensor and the one or more characteristics measured by the third sensor by comparing a signal from at least one of the first sensor, the second sensor and the third sensor in an area of the sample absent of photoluminescing defects to a signal from at least one of the first sensor, the second sensor and the third sensor acquired from a measured region of the sample.

3. The system of claim 1 , wherein the controller is further configured to map the detected one or more photoluminescence defects based on at least one of the one or more characteristics measured by the first sensor, the one or more characteristics measured by the second sensor and the one or more characteristics measured by the third sensor and a position of the detected one or more photoluminescence defects.

4. The system of claim 1 , wherein the controller is further configured to classify the detected one or more photoluminescence defects based on at least one of the one or more characteristics measured by the first sensor, the one or more characteristics measured by the second sensor and the one or more characteristics measured by the third sensor.

5. The system of claim 1 , wherein the one or more photoluminescing defects of the sample comprise:
at least one of one or more stacking fault defects and one or more basal plane dislocations.

6. The system of claim 1 , wherein the controller is further configured to differentiate the detected one or more scattering defects as pit defects or particle defects based on the light detected by at least one of the second and third sensors.

7. The system of claim 1 , wherein the controller is configured to selectably deactivate the first radiation source prior to at least one of measurement of the second portion of radiation by the second sensor and measurement of the third portion of radiation by the third sensor in order to detect one or more photoluminescence defects based on the light detected by at least one of the second sensor and the third sensor.

8. The system of claim 1 , wherein the sample is a semiconductor device.

9. The system of claim 8 , wherein the semiconductor device is a wide-bandgap semiconductor device.

10. The system of claim 1 , wherein at least one of the oblique-incidence source and the normal-incidence source is a laser.

11. The system of claim 1 , wherein at least one of the oblique-incidence source and the normal-incidence source is an ultraviolet laser.

12. The system of claim 1 , wherein at least one of the oblique-incidence source and the normal-incidence source is a continuous wave (CW) laser.

13. The system of claim 1 , wherein the sample stage assembly configured to secure the sample and selectively actuate the sample in order to perform a scanning process with at least the oblique-incidence radiation source and the normal-incidence radiation source comprises:
a rotational stage assembly configured to secure the sample and selectively rotate the sample in order to perform a spiral scanning process with at least the oblique-incidence radiation source and the normal-incidence radiation source.

14. The system of claim 1 , wherein the sample stage assembly configured to secure the sample and selectively actuate the sample in order to perform a scanning process with at least the oblique-incidence radiation source and the normal-incidence radiation source comprises:
a linear stage assembly configured to secure the sample and selectively translate the sample along at least a first direction and a second direction perpendicular to the first direction in order to perform an X-Y scanning process with at least the oblique-incidence radiation source and the normal-incidence radiation source.

15. The system of claim 1 , wherein the filter sub-system includes:
a first optical element configured to separate a first spectral range of radiation including the first portion of radiation from the radiation received from the sample and direct the first spectral range of radiation toward the first sensor;
a second optical element configured to receive radiation from the first optical element not included in the first spectral range of radiation, wherein the second optical element is configured to separate a second spectral range of radiation including the second portion of radiation from the radiation received from the first optical element and direct the second spectral range of radiation toward the second sensor; and
a third optical element configured to receive radiation from the second optical element not included in the first spectr

Assignees

• Kla Tencor Corp

Inventors

• Sappey Romain

Classifications

• G01N2021/8845

  Multiple wavelengths of illumination or detection · CPC title

• G01N21/6489 Primary

  Photoluminescence of semiconductors · CPC title

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title

• G01N2201/0662

  Comparing measurements on two or more paths in one sample · CPC title

• G01N2021/6495

  Miscellaneous methods · CPC title