Method and device for measuring temperature of substrate in vacuum processing apparatus

1. A method for determining a temperature of a substrate in a vacuum processing apparatus, the substrate to be measured being placed on a susceptor in the vacuum processing apparatus for a manufacture process, wherein the method comprises:

selecting i wavelengths from radiance emitted from the susceptor through the substrate, wherein i is a natural number greater than 1;

obtaining at least i pieces of radiance corresponding to the selected i wavelengths; and

calculating the temperature of the substrate based on the i pieces of radiance and the i wavelengths, by using a mathematical equation:

E (λ i )= T ( d )× M (λ i ,T ),

wherein λ i is the i th wavelength, T is the temperature of the substrate, E(λ i ) is an i th radiant quantity corresponding to the i th wavelength λ i , T(d) is transmittance of the substrate, which is a function of thickness d of a film grown on the substrate, and M(λ i ,T) is blackbody radiation equation, which is a function of the i th wavelength λ i and the temperature of the substrate T.

2. The method according to claim 1 , wherein

the vacuum processing apparatus comprises a Metal-Organic Chemical Vapor Deposition (MOCVD) reactor, and

at least one film is grown on the substrate by epitaxy in the manufacture process, so that the substrate has a structure including a base material and the at least one film.

3. The method according to claim 1 , wherein the blackbody radiation equation is:

M

⁡

(

λ

i

,

T

)

=

2

⁢

⁢

π

⁢

⁢

hc

2

λ

5

⁢

1

ⅇ

hc

/

λ

⁢

⁢

kT

-

1

,

wherein h is Planck constant, c is light speed, and k is Boltzmann constant.

4. The method according to claim 3 , wherein the transmittance of the substrate is determined by:

T ( d )=1− R,

wherein R is a refractive index,

the refractive index is determined by:

R=rr*,

wherein r is amplitude reflectance, and r* is conjugation of r,

the amplitude reflectance is determined by:

r

=

n

0

-

Y

n

0

+

⁢

Y

,

wherein n 0 is a refractive index of a medium in which the radiance is transmitted through the substrate, and Y is an equivalent refractive index:

Y

=

B

C

,

wherein B and C are determined by the following matrix:

(

B

C

)

=

(

cos

⁢

⁢

δ

1

i

⁢

⁢

sin

⁢

⁢

δ

1

η

1

i

⁢

⁢

η

1

⁢

sin

⁢

⁢

δ

1

cos

⁢

⁢

δ

1

)

⁢

(

1

η

2

)

,

wherein η 1 and η 2 are determined by:

for a p-component, η 1 =n 1 /cos θ, and η 2 =n 2 /cos θ; and

for a s-component, η 1 =n 1 cos θ, and η 2 =n 2 cos θ,

θ is an angle between a direction in which the radiance is obtained and a normal, and δ 1 is determined by:

δ

1

=

2

⁢

⁢

π

⁢

⁢

n

1

⁢

d

1

λ

i

⁢

cos

⁢

⁢

θ

,

wherein d 1 represents thickness of a top film on the substrate, λ i represents the i th wavelength selected from the radiance, n 1 represents a refractive index of the top film on the substrate, and n 2 represents an equivalent refractive index of a base material and films except the top film of the substrate.

5. The method according to claim 4 , further comprising:

selecting any two wavelengths from the i wavelengths, wherein i is equal to or greater than 3; and

obtaining C i 2 substrate temperature values T and C i 2 film thickness values d, by substituting the selected two wavelengths for the wavelength in the mathematical equation:

E (λ i )= T ( d )× M (λ i ,T ).

6. The method according to claim 5 , further comprising:

comparing the temperature of the substrate with a pre-stored reference substrate temperature; and

controlling a heater in the vacuum processing apparatus to adjust the current temperature of the substrate.

7. A device for determining a temperature of a substrate in a vacuum processing apparatus, the substrate to be measured being placed on a susceptor in the vacuum processing apparatus for a manufacture process, wherein the device comprises:

a wavelength selecting means, adapted to select i wavelengths from radiance emitted from the susceptor through the substrate, wherein i is a natural number greater than 1;

a radiant quantity obtaining means, adapted to obtain at least i pieces of radiance corresponding to the selected i wavelengths; and

a calculating and analyzing means, adapted to calculate the temperature of the substrate based on the i pieces of radiance and the i wavelengths, by using a mathematical equation:

E (λ i )= T ( d )× M (λ i ,T ),

wherein λ i is the i th wavelength, T is the temperature of the substrate, E(λ i ) is an i th radiant quantity corresponding to the i th wavelength λ i , T(d) is transmittance of the substrate, which is a function of thickness d of a film grown on the substrate, and M(λ i ,T) is blackbody radiation equation, which is a function of the i th wavelength λ i and the temperature of the substrate T.

8. The device according to claim 7 , wherein

the vacuum processing apparatus comprises a Metal-Organic Chemical Vapor Deposition (MOCVD) reactor, and

at least one film is grown on the substrate by epitaxy in the manufacture process, so that the substrate has a structure including a base material and the at least one film.

9. The device according to claim 7 , wherein the blackbody radiation equation is:

M

⁡

(

λ

i

,

T

)

=

2

⁢

⁢

π

⁢

⁢

hc

2

λ

5

⁢

1

ⅇ

hc

/

λ

⁢

⁢

kT

-

1

,

wherein h is Planck constant, c is light speed, and k is Boltzmann constant.

10. The device according to claim 9 , wherein the transmittance of the substrate is determined by:

T ( d )=1− R,

wherein R is a refractive index,

the refractive index is determined by:

R=rr*,

wherein r is amplitude reflectance, and r* is conjugation of r,

the amplitude reflectance is determined by:

r

=

n

0

-

Y

n

0

+

⁢

Y

,

wherein n 0 is a refractive index of a medium in which the radiance is transmitted through the substrate, and Y is an equivalent refractive index:

Y

=

B

C

,

wherein B and C are determined by the following matrix:

(

B

C

)

=

(

cos

⁢

⁢

δ

1

i

⁢

⁢

sin

⁢

⁢

δ

1

η

1

i

⁢

⁢

η

1

⁢

sin

⁢

⁢

δ

1

cos

⁢

⁢

δ

1

)

⁢

(

1

η

2

)

,

wherein η 1 and η 2 are determined by:

for a p-component, η 1 =n 1 /cos θ, and η 2 =n 2 /cos θ; and

for a s-component, η 1 =n 1 cos θ, and η 2 =n 2 cos θ,

θ is an angle between a direction in which the radiance is obtained and a normal, and δ 1 is determined by:

δ

1

=

2

⁢

⁢

π

⁢

⁢

n

1

⁢

d

1

λ

i

⁢

cos

⁢

⁢

θ

,

wherein d 1 represents thickness of a top film on the substrate, λ i represents the i th wavelength selected from the radiance, n 1 represents a refractive index of the top film on the substrate, and n 2 represents an equivalent refractive index of a base material and films except the top film of the substrate.

11. The device according to claim 10 , wherein the calculating and analyzing means is connected to a Metal-Organic Chemical Vapor Deposition reactor, and is further adapted to:

select any two wavelengths from the i wavelengths, wherein i is equal to or greater than 3; and

obtain C i 2 substrate temperature values T and C i 2 film thicknesses values d, by substituting the selected two wavelengths for the wavelength in the mathematical equation:

E (λ i )= T ( d )× M (λ i ,T ).

12. The device according to claim 11 , wherein

a reference substrate temperature is pre-stored in the calculating and analyzing means, and

the calculating and analyzing means is further adapted to:

compare the temperature of the substrate with the pre-stored reference substrate temperature; and

control a heater in the vacuum processing apparatus to adjust the current temperature of the substrate.

13. A device for determining a temperature of a substrate in a vacuum processing apparatus, the substrate to be measured being placed on a susceptor in the vacuum processing apparatus for a manufacture process, the vacuum processing apparatus comprising a chamber, and an observation opening being provided on the top of the chamber, wherein the device comprises:

an optical module, adapted to select i wavelengths from radiance emitted from the susceptor through the substrate, obtain at least i pieces of radiance corresponding to the selected i wavelengths, and convert an optical signal containing the i wavelengths and the i pieces of radiance into an electrical signal, wherein i is a natural number greater than 1;

an analog module, adapted to amplify and de-noise the electrical signal;

a digital synchronization module, adapted to perform Analog to Digital (A/D) conversion and synchronization on the amplified and de-noised electrical signal; and

a calculating and analyzing means in which a mathematical equation of E(λ i )=T(d)×M(λ i ,T) is pre-stored, wherein the calculating and analyzing means is adapted to calculate the temperature of the substrate based on the i pieces of radiance and the i wavelengths, by using the mathematical equation:

E (λ i )= T ( d )× M (λ i ,T ),

wherein λ i is the i th wavelength, T is the temperature of the substrate, E(λ i ) is an i th radiant quantity corresponding to the i th wavelength λ i , T (d) is transmittance of the substrate, which is a function of thickness d of a film grown on the substrate, and M(λ i ,T) is blackbody radiation equation, which is a function of the i th wavelength λ i and the temperature of the substrate T.

14. The device according to claim 13 , wherein the optical module comprises:

a first lens, provided above the observation opening, and adapted to converge, direct and transmit to spectroscopes the radiance emitted from the susceptor through a substrate;

i-1 spectroscopes, adapted to divide the optical signal containing the radiance transmitted from the first lens into optical signals in different wavelength intervals;

i filters, adapted to select i wavelengths from the optical signals containing different wavelengths divided by the spectroscopes, and obtain at least i pieces of radiance corresponding to the selected i wavelengths from the optical signals;

i second lenses, adapted to converge and direct, to a plurality of sensors, the optical signals containing the i wavelengths and the at least i pieces of radiance corresponding to the i wavelengths; and

i sensors, adapted to convert the optical signals transmitted from the i second lenses into electrical signals respectively,

wherein the i filters, the i second lenses, and the i sensors are divided into i groups, one filter, one second lens and one sensor are connected in series in this order in each group, and the i groups output in parallel i electrical signals containing the i wavelengths and the at least i pieces of radiance corresponding to the i wavelengths,

or, the optical module comprises:

a lens, provided above the observation opening, and adapted to converge, direct and transmit to a fiber the radiance emitted from the susceptor through a substrate;

an optical fiber, connected to the lens, and adapted to transmit the radiance transmitted from the lens to i filters;

the i filters, adapted to select i wavelengths from the optical signal containing the radiance, and obtain at least i pieces of radiance corresponding to the selected i wavelengths from the optical signal; and

i sensors, adapted to convert the optical signals transmitted from the i filters into electrical signals respectively,

wherein the i filters and the i sensors are divided into i groups, one filter and one sensor are connected in series in this order in each group, and the i groups output in parallel i electrical signals containing the i wavelengths and the at least i pieces of radiance corresponding to the i wavelengths.

15. The device according to any one of claims 13 , wherein the analog module comprises:

i amplifiers, adapted to amplify the electrical signals transmitted from the optical module; and

i filters, adapted to de-noise the amplified electrical signals,

wherein the i amplifiers and the i filters are divided into i groups, one amplifier and one filter are connected in series in this order in each group, and the i groups output in parallel i analog electrical signals containing the i wavelengths and the at least i pieces of radiance corresponding to the i wavelengths.

16. The device according to claim 15 , wherein the digital synchronization module comprises:

i Analog to Digital (A/D) converters, connected to the analog module and adapted to convert the analog electrical signals transmitted from the analog module into digital signals respectively; and

a Field Programmable Gate Array (FPGA), connected to the i Analog to Digital converters and adapted to synchronize the digital signals.

17. The device according to claim 16 , wherein the blackbody radiation equation is:

M

⁡

(

λ

i

,

T

)

=

2

⁢

⁢

π

⁢

⁢

hc

2

λ

5

⁢

1

ⅇ

hc

/

λ

⁢

⁢

kT

-

1

,

wherein h is Planck constant, c is light speed, and k is Boltzmann constant.

18. The device according to claim 17 , wherein the transmittance of the substrate is determined by:

T ( d )=1− R,

wherein R is a refractive index,

the refractive index is determined by:

R=rr*,

wherein r is amplitude reflectance, and r* is conjugation of r,

the amplitude reflectance is determined by:

r

=

n

0

-

Y

n

0

+

⁢

Y

,

wherein n 0 is a refractive index of a medium in which the radiance is transmitted through the substrate, and Y is an equivalent refractive index:

Y

=

B

C

,

wherein B and C are determined by the following matrix:

(

B

C

)

=

(

cos

⁢

⁢

δ

1

i

⁢

⁢

sin

⁢

⁢

δ

1

η

1

i

⁢

⁢

η

1

⁢

sin

⁢

⁢

δ

1

cos

⁢

⁢

δ

1

)

⁢

(

1

η

2

)

,

wherein η 1 and η 2 are determined by:

for a p-component, η 1 =n 1 /cos θ, and η 2 =n 2 /cos θ; and

for a s-component, η 1 =n 1 cos θ, and η 2 =n 2 cos θ,

θ is an angle between a direction in which the radiance is obtained and a normal, and δ 1 is determined by:

δ

1

=

2

⁢

⁢

π

⁢

⁢

n

1

⁢

d

1

λ

i

⁢

cos

⁢

⁢

θ

,

wherein d 1 represents thickness of a top film on the substrate, λ i represents the i th wavelength selected from the radiance, n 1 represents a refractive index of the top film on the substrate, and n 2 represents an equivalent refractive index of a base material and films except the top film of the substrate.

19. The device according to claim 18 , wherein the calculating and analyzing means is connected to a Metal-Organic Chemical Vapor Deposition reactor, and is further adapted to:

select any two wavelengths from the i wavelengths, wherein i is equal to or greater than 3; and

obtain C i 2 substrate temperature values T and C i 2 film thickness values d, by substituting the selected two wavelengths for the wavelength in the mathematical equation:

E (λ i )= T ( d )× M (λ i ,T ).

20. The device according to claim 19 , wherein

a reference substrate temperature is pre-stored in the calculating and analyzing means, and

the calculating and analyzing means is further adapted to:

compare the temperature of the substrate with the reference substrate temperature; and

control the vacuum processing apparatus to adjust the current temperature of the substrate.