3D profiling system of semiconductor chip and method for operating the same

Patent metadata

Field	Value
Publication number	US-10068324-B2
Application number	US-201615291590-A
Country	US
Kind code	B2
Filing date	Oct 12, 2016
Priority date	Dec 7, 2015
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

A 3D profiling system of a semiconductor chip is provided and includes a storage unit that receives scanning electron microscope (SEM) images of a plurality of semiconductor devices having respective data with respect to a plurality of different components and gray levels of each SEM image. An extraction unit that performs principal component analysis (PCA) on the gray level of the SEM image and separates principal components from among the plurality of different components is also part of the system. Additionally, a calculation unit receives provision of actually measured values of the plurality of semiconductor devices, and applies a multiple linear regression to the principal components based on the measured values to complete a 3D profile of the semiconductor chip.

First claim

What is claimed is:

1. A 3D profiling system of a semiconductor chip comprising:
a storage unit that receives scanning electron microscope (SEM) images of a plurality of semiconductor devices having respective data with respect to a plurality of different components from an SEM and gray levels of the SEM images;
an extraction circuit that performs principal component analysis (PCA) on the gray levels of the SEM images and separates principal components among the plurality of different components; and
a calculation circuit that receives measured values of the plurality of semiconductor devices related to shapes of the plurality of semiconductor devices, and applies a multiple linear regression to the principal components based on the measured values to complete a 3D profile of the semiconductor chip.

2. The system of claim 1 , wherein application of the multiple linear regression to the principal components by the calculation circuit comprises a relational formula that includes a correlation coefficient between the gray levels of the SEM images and the principal components.

3. The system of claim 2 , wherein the correlation coefficients between the gray levels and the principal components differ from one another.

4. The system of claim 2 , wherein the relational formula comprises

S
=

∑

k
=
1

j

⁢

⁢

(

y
k

-

a
0

-

∑

i
=
1

n

⁢

⁢

a
i

⁢

x
i

)

2

wherein S is the gray level, y k is a component of a k th semiconductor device obtained by actual measurement, a i is a correlation coefficient, x i is the principal component and a 0 is a constant.

5. The system of claim 2 , wherein the calculation circuit receives provision of the measured value of a target semiconductor device, and corrects the correlation coefficient between the gray level of the SEM images and the principal components.

6. The system of claim 1 , wherein the plurality of different components comprises at least one of a depth of the semiconductor device, a top critical dimension (TCD), a bottom critical dimension (BCD) and a profile angle of opposing side walls.

7. The system of claim 1 , wherein each of the SEM images comprise a first image of the semiconductor device acquired by a first acceleration voltage, and a second image of the semiconductor device acquired by a second acceleration voltage different from the first acceleration voltage.

8. The system of claim 7 , wherein the first image comprises data of a first height of the semiconductor device, and the second image comprises data of a second height different from the first height of the semiconductor device.

9. The system of claim 1 , wherein the plurality of semiconductor devices comprises a first semiconductor device and a second semiconductor device, and
the data of the plurality of different components of the first semiconductor device are different from the data of the plurality of different components of the second semiconductor device.

10. The system of claim 1 , wherein the separation of the principal components by the extraction circuit comprises separation of the components in which a correlation coefficient with the gray level is a predetermined value among the plurality of different components.

11. The system of claim 1 , wherein the SEM images comprises images of secondary electron (SE) or backscattered electron (BSE).

12. A 3D profiling system of a semiconductor chip comprising:
an electron irradiation unit that irradiates an electron beam toward a plurality of semiconductor devices having respective data for a plurality of different components;
a stage that supports the semiconductor devices;
a detecting circuit that detects intensity of the electrons emitted from the semiconductor devices to generate a gray level of an SEM image;
an extraction circuit that performs PCA on the gray level of the SEM image to separate principal components from among the plurality of different components; and
a calculation circuit that receives provision of measured values of the plurality of semiconductor devices related to shapes of the plurality of semiconductor devices, and applies a multiple linear regression to the principal components based on the measured values to complete a 3D profile of the semiconductor chip.

13. The system of claim 12 , further comprising:
a storage unit that receives provision of the gray level of the SEM image, stores the gray level and provides the gray level to the extraction circuit.

14. The system of claim 12 , wherein the detecting circuit detects one of secondary electrons (SE) or backscattered electrons (BSE).

15. The system of claim 12 , wherein the semiconductor chip comprises a first region and a second region, and
the detecting circuit detects the gray level of secondary electrons (SE) of the first region and detects the gray level of backscattered electrons (BSE) of the second region.

16. A 3D profiling system of a semiconductor chip comprising:
an electron irradiation unit that irradiates an electron beam toward each of a plurality of semiconductor devices having respective data for a plurality of different components, said electron beam having a first electron beam intensity for obtaining 3D profiling information relating to a top surface of each of the plurality of semiconductor devices and having a second electron beam intensity for obtaining 3D profiling information relating to a bottom surface of each of the plurality of semiconductor devices;
a detecting circuit that detects the intensity of the electrons emitted from the plurality of semiconductor devices to generate gray levels of SEM images reflecting the 3D profiling information relating to the top and bottom surfaces of each of the plurality of semiconductor devices;
an extraction circuit that performs PCA on the gray levels of the SEM images to separate principal components from among the plurality of different components for each of the plurality of semiconductor devices; and
a calculation circuit that receives measured values for each of the plurality of the semiconductor devices related

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Jung Soo
• Kim Jin Kwan
• Jun Chung Sam
• Yang Yu Sin
• Lee Soo Seok

Classifications

• G06T7/529 Primary

  from texture · CPC title

• G06T7/0004 Primary

  Industrial image inspection · CPC title

• H01J2237/225

  Displaying image using synthesised colours · CPC title

• G06T2207/10061

  from scanning electron microscope · CPC title

• H01J37/28

  with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} · CPC title