Semiconductor device inspection device and semiconductor device inspection method

Patent metadata

Field	Value
Publication number	US-9588175-B2
Application number	US-201314440175-A
Country	US
Kind code	B2
Filing date	Oct 25, 2013
Priority date	Nov 6, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A semiconductor device inspection system ( 1 ) includes a laser beam source ( 2 ), for emitting light, an optical sensor ( 12 ) for detecting the light reflected by the semiconductor device ( 10 ) from the light and outputting a detection signal, a frequency band setting unit ( 16 ) for setting a measurement frequency band and a reference frequency band with respect to the detection signal, a spectrum analyzer ( 15 ) for generating a measurement signal and a reference signal from the detection signals in the measurement frequency band and the reference frequency band, and a signal acquisition unit ( 17 ) for calculating a difference between the measurement signal and the reference signal to acquire an analysis signal. The frequency band setting unit ( 16 ) sets the reference frequency band to a frequency domain in which a level of the detection signal is lower than a level obtained by adding 3 decibels to a white noise level serving as a reference.

First claim

The invention claimed is:

1. A system for inspecting a semiconductor device serving as a device under test, the system comprising:
a light source configured to generate light to be irradiated the semiconductor device;
a light detector configured to detect reflected light that is reflected from the semiconductor device and output a detection signal;
a frequency band setting unit configured to set a measurement frequency band and a reference frequency band with respect to the detection signal;
a signal generating unit electrically coupling the frequency band setting unit and configured to generate a measurement signal from the detection signal in the measurement frequency band and generate a reference signal from the detection signal in the reference frequency band; and
a signal acquisition unit electrically coupling the signal generating unit and configured to calculate a difference between the measurement signal and the reference signal to acquire an analysis signal,
wherein, when a level of the detection signal is calculated based on power, the frequency band setting unit sets the reference frequency band to a frequency domain in which the level is lower than a level obtained by adding 3 decibels to a white noise level serving as a reference.

2. The system according to claim 1 , wherein the frequency band setting unit sets the reference frequency band to the frequency domain having a frequency higher than the measurement frequency band.

3. The system according to claim 1 , wherein the frequency band setting unit sets the reference frequency band to include a frequency of a system noise included in the measurement frequency band.

4. The system according to claim 1 , further comprising an electrical signal application unit configured to apply a first electrical signal having a first modulation frequency to the semiconductor device,
wherein the frequency band setting unit sets the measurement frequency band to include a frequency that is a natural number times the first modulation frequency.

5. The system according to claim 4 , wherein the electrical signal application unit applies a second electrical signal having a second modulation frequency different from the first modulation frequency to the semiconductor device together with the first electrical signal, and
the frequency band setting unit sets the measurement frequency band to include a frequency that is a natural number times the first modulation frequency, and sets the reference frequency band to include a frequency that is a natural number times the second modulation frequency.

6. The system according to claim 1 , further comprising:
a first power source configured to operate the light source; and
a second power source separately installed from the first power source and configured to operate the light detector.

7. The system according to claim 1 , wherein the signal generating unit comprises a spectrum analyzer configured to generate the measurement signal from the detection signal in the measurement frequency band and generate the reference signal from the detection signal in the reference frequency band.

8. The system according to claim 1 , wherein the signal generating unit comprises a first lock-in amplifier configured to generate the measurement signal from the detection signal in the measurement frequency band, and a second lock-in amplifier configured to generate the reference signal from the detection signal in the reference frequency band.

9. The system according to claim 1 , wherein the signal generating unit comprises a first spectrum analyzer configured to generate the measurement signal from the detection signal in the measurement frequency band, and a second spectrum analyzer configured to generate the reference signal from the detection signal in the reference frequency band.

10. A system for inspecting a semiconductor device inspection serving as a device under test, the system comprising:
a light source configured to generate light to be irradiated the semiconductor device;
a light detector configured to detect reflected light that is reflected from the semiconductor device and output a detection signal;
a frequency band setting unit configured to set a measurement frequency band and a reference frequency band with respect to the detection signal;
a signal generating unit electrically coupling the frequency band setting unit and configured to generate a measurement signal from the detection signal in the measurement frequency band and generate a reference signal from the detection signal in the reference frequency band; and
a signal acquisition unit electrically coupling the signal generating unit and configured to calculate a difference between the measurement signal and the reference signal to acquire an analysis signal,
wherein, when a level of the detection signal is calculated based on amplitude energy, the frequency band setting unit sets the reference frequency band to a frequency domain in which the level is lower than a level obtained by adding 6 decibels to a white noise level serving as a reference.

11. A method for inspecting a semiconductor device serving as a device under test, the method comprising:
irradiating the with light;
detecting reflected light that is reflected from the semiconductor device and outputting a detection signal;
setting a measurement frequency band and a reference frequency band with respect to the detection signal;
generating a measurement signal from the detection signal in the measurement frequency band and generating a reference signal from the detection signal in the reference frequency band; and
calculating a difference between the measurement signal and the reference signal to acquire an analysis signal,
wherein, in the setting, when a level of the detection signal is calculated based on power, the reference frequency band is set to a frequency domain in which the level is lower than a level obtained by adding 3 decibels to a white noise level serving as a reference.

12. A method for inspecting a semiconductor device serving as a device under test, the method comprising:
irradiating the semiconductor device with light,
detecting reflected light that is reflected from the semiconductor device and outputting a detection signal;
setting a measurement frequency band and a reference frequency band with respect to the detection signal;
generating a measurement signal from the detection signal in the measurement frequency band and generating a reference signal from the detection signal in the reference frequency band; and
calculating a difference between the measurement signal and the reference signal to acquire an analysis signal,
wherein, in the setting, when a level of the detection signal is calculated based on amplitude energy, the reference frequency band is set to a frequency domain in which the level is lower than a level obtained by adding 6 decibels to a white noise level serving as a reference.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Nakamura Tomonori

Classifications

• G01R31/2601

  Apparatus or methods therefor (G01R31/2607, G01R31/2642 take precedence) · CPC title

• G01R31/308

  using non-ionising electromagnetic radiation, e.g. optical radiation {(investigating or analysing materials by the use of optical means G01N21/00; image analysis G06T7/00)} · CPC title

• G01R1/071

  containing electro-optic elements · CPC title

• G01N21/95607

  using a comparative method · CPC title

• G01R31/26

  Testing of individual semiconductor devices (testing of photovoltaic devices H02S50/10; testing or measuring during manufacture or treatment {H10P74/00}) · CPC title