Method of calculating thickness of graphene layer and method of measuring content of silicon carbide by using XPS

Patent metadata

Field	Value
Publication number	US-11906291-B2
Application number	US-202117145966-A
Country	US
Kind code	B2
Filing date	Jan 11, 2021
Priority date	May 26, 2020
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

A method of calculating a thickness of a graphene layer and a method of measuring a content of silicon carbide, by using X-ray photoelectron spectroscopy (XPS), are provided. The method of calculating the thickness of the graphene layer, which is directly grown on a silicon substrate, includes measuring the thickness of the graphene layer directly grown on the silicon substrate, by using a ratio between a signal intensity of a photoelectron beam emitted from the graphene layer and a signal intensity of a photoelectron beam emitted from the silicon substrate.

First claim

What is claimed is:

1. A method of measuring a thickness of a graphene layer directly grown on a silicon substrate, by using an X-ray photoelectron spectroscopy (XPS) instrument, the method comprising:
emitting X-ray radiation toward the graphene layer directly grown on the silicon substrate using a source on the XPS instrument;
obtaining signal intensities from the graphene layer directly grown on the silicon substrate in response to emitting the X-ray radiation toward the graphene layer directly grown on the silicon substrate using a sensor on the XPS instrument; and
calculating the thickness t G of the graphene layer according to an equation below,

t
G

=

λ

E
⁢
A
⁢
L

⁢
cos
⁢

⁢
α
⁢

⁢
ln
⁢

⁢

(

R
exp

R
0

+
1

)

wherein
⁢

⁢

R
0

=

I

c
⁢
o

I

s
⁢
i
⁢
o

,

R
exp

=

I
C

I

s
⁢
i

,

λ REAL is an effective attenuation length,
α is a detection angle for the XPS instrument,
I co is a signal intensity of a photoelectron beam emitted from bulk-type graphene,
I sio is a signal intensity of a photoelectron beam emitted from bulk-type silicon,
I c is a signal intensity of a photoelectron beam emitted from the graphene layer and obtained by the sensor on the XPS instrument in response to the graphene layer receiving X-ray radiation by the XPS instrument, and
I si is a signal intensity of a photoelectron beam emitted from the silicon substrate and obtained by the sensor on the XPS instrument in response to the silicon substrate receiving X-ray radiation by the XPS instrument,
wherein R 0 is obtained by a linear relationship between the signal intensity I si of the photoelectron beam emitted from the silicon substrate and the signal intensity I c of the photoelectron beam emitted from the graphene layer using the XPS instrument.

2. The method of claim 1 , wherein the graphene layer includes crystalline graphene or nanocrystalline graphene.

3. The method of claim 1 , further comprising:
obtaining the effective attenuation length via calibration, from a linear relationship between results of measurement by a transmission electron microscope and results of measurement by the XPS.

4. The method of claim 1 , wherein the bulk-type graphene has a thickness that is greater than or equal to about 10 nm.

5. A method of measuring a thickness of a graphene layer directly grown on a silicon substrate such that an interface layer is formed between the silicon substrate and the graphene layer, by using an X-ray photoelectron spectroscopy (XPS) instrument, the method comprising:
emitting X-ray radiation toward the graphene layer directly grown on the silicon substrate using a source on the XPS instrument;
obtaining signal intensities from the graphene layer directly grown on the silicon substrate in response to emitting the X-ray radiation toward the graphene layer directly grown on the silicon substrate using a sensor on the XPS instrument; and
calculating the thickness t G of the graphene layer according to an equation below,

t
G

=

λ

E
⁢
A
⁢
L

⁢

⁢
cos
⁢

⁢
α
⁢

⁢

ln
(

I
C

R
0

K
+

I

s
⁢
i

+

⁢
1

)

wherein
⁢

⁢

R
0

=

I

c
⁢
o

I

s
⁢
i
⁢
o

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Eunkyu
• Cho Yeonchoo
• Kim Sangwon
• Byun Kyung-Eun
• Song Hyunjae
• Shin Hyeonjin

Classifications

• H10P74/203 Primary

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

• H10D64/0111

  to Group IV semiconductors · CPC title

• H10D64/62

  Electrodes ohmically coupled to a semiconductor · CPC title

• H10P74/00

  Testing or measuring during manufacture or treatment of wafers, substrates or devices · CPC title

• G01B15/02 Primary

  for measuring thickness · CPC title