Chip defect detection device and detection method

Patent metadata

Field	Value
Publication number	US-10942129-B2
Application number	US-201716343913-A
Country	US
Kind code	B2
Filing date	Oct 20, 2017
Priority date	Oct 20, 2016
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

An apparatus and method for die defect detection are disclosed. The apparatus includes: a light source unit (10) for emitting light of at least two wavelengths; a beam splitter (40) for receiving the light emitted by the light source unit (10) and splitting it into a first portion and a second portion, the first portion of the light reflected by a die (60) surface under inspection and thereby forming a detection beam; a reference unit (70) for receiving the second portion of the light and processing it into a reference beam; and a detection unit (90) for receiving the detection beam and the reference beam. The reference beam crosses the detection beam at an angle and thus produces interference fringes on a sensing surface of the detection unit (90), based on which a defect parameter of the die (60) surface under inspection is determined. This apparatus is capable of measuring a die with improved accuracy and efficiency and is suitable for the measurement of large dies.

First claim

What is claimed is:

1. An apparatus for die defect detection, comprising:
a light source unit for emitting light of two wavelengths;
a beam splitter for splitting the light emitted by the light source unit into a first portion and a second portion, the first portion reflected by a die surface under inspection and thereby forming a detection beam;
a reference unit having a surface configured to receive the second portion of the light and thereby form a reference beam; and
a detection unit for receiving the detection beam and the reference beam, wherein the reference beam crosses the detection beam at an angle and thus forming interference signals on a sensing surface of the detection unit, and wherein a defect parameter of the die surface under inspection is determined based on the interference signals;
wherein intensities, detected by the detection unit, of light with a shorter wavelength and of light with a synthetic wavelength generated from the two wavelengths respectively satisfy:

⁢

I
1

≈

cos
⁡

(

2
⁢
π

λ
1

·
2

⁢

(

z
+

x
·
sin

⁢

⁢
θ

)

)

;

I
2

≈

cos
⁡

[

(

2
⁢
π

λ
1

-

2
⁢
π

λ
2

)

·
2

⁢

(

z
+

x
·
sin

⁢

⁢
θ

)

]

=

cos
⁡

[

2
⁢
π
⁢

λ
2

-

λ
1

λ
1

⁢

λ
2

·
2

⁢

(

z
+

x
·
sin

⁢

⁢
θ

)

]

,

where: I 1 represents the intensity of the light with the shorter wavelength λ 1 ; I 2 represents the intensity of the light with the synthetic wavelength generated from the two wavelengths λ 1 and λ 2 ; θ represents an angle at which the surface of the reference unit is inclined with respect to a vertical direction perpendicular to the die surface under inspection; z represents a height of a measurement point on the die surface under inspection; and x represents a horizontal position of a sensing pixel in the detection unit.

2. The apparatus for die defect detection of claim 1 , wherein the detection unit comprises at least one detector for detecting the interference signals.

3. The apparatus for die defect detection of claim 2 , wherein the detection unit comprises a plurality of detectors, each configured for the detection of light with a corresponding one of the wavelengths.

4. The apparatus for die defect detection of claim 2 , wherein the detector is implemented as a complementary metal oxide sem

Assignees

• Shanghai Micro Electronics Equipment Group Co Ltd

Inventors

• Zhang Pengli
• Lu Hailiang
• Wang Fan

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• G01B9/02032 Primary

  generating a spatial carrier frequency, e.g. by creating lateral or angular offset between reference and object beam (shearing interferometers G01B9/02098) · CPC title

• G01N21/95 Primary

  characterised by the material or shape of the object to be examined (G01N21/89 - G01N21/91, G01N21/94 take precedence) · CPC title

• G01B9/021

  using holographic techniques · CPC title

• G01B2210/48

  for measurement of a wafer · CPC title