US 2025/0154655 A1Published application

Method for emissivity-corrected pyrometry

AssigneeAixtron SE

InventorKarsten ROJEK

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Abstract

A method for coating a substrate with at least one layer. During deposition of the layer, at least one optical measuring device repeatedly determines successive measurement value pairs on the layer, each containing an emission value corresponding to the radiation power measured at a light wavelength and a reflectance value, which is also measured at a light wavelength. Actual values of a substrate temperature are calculated based on the measurement value pairs and a previously determined correction value. The actual values are used to control a temperature-control device for controlling the substrate temperature to a desired value. To improve the determination of the correction factor, during the measurement and within a plurality of measurement intervals, at least two measurement value pairs are measured and, for each of the measurement intervals, a temperature-dependent factor is determined that is used for the calculation of the correction value.

Claims14

Dependent claims

A method for coating a substrate (22) with at least one layer (23 to 31), the method comprising:

depositing the at least one layer (23 to 31) on the substrate (22);
while depositing the at least one layer (23 to 31), repeatedly measuring by at least one optical measuring device (11, 12) successive measurement value pairs {UE,n, UR,n} on the at least one layer (23 to 31), each measurement value pair containing an emission value UE corresponding to a radiation power measured at a light wavelength, and a reflectance value UR, which is also measured at the light wavelength;
calculating temperature values TC of the at least one layer (23 to 31) on the substrate (22) from the measurement value pairs {UE,n, UR,n} using equations:
U
E
=
A
·
e
B
T
·
(
1
-
α
·
γ
·
U
R
)
⁢
and
U
E
=
C
⁢
(
T
)
-
C
⁢
(
T
)
·
α
·
γ
·
U
R
,
wherein:
A is a first calibration parameter,
B is a second calibration parameter in which B<0,
α is a reflectance normalization calibration parameter which relates the reflectance value UR and a physical reflectance R, where 0≤R≤1,
γ is a correction value, and
C(T) is a temperature-dependent factor that satisfies
C
⁢
(
T
)
=
A
·
e
B
T
wherein at least two of the measurement value pairs {UE,n, UR,n} are each measured during a measurement duration within a plurality of measurement intervals ti, 1≤i≤k;
determining the temperature-dependent factor Ci(Ti) for each of the measurement intervals ti;
and
calculating the correction value γ based on the temperature-dependent factor Ci(Ti) determined for each of the measurement intervals ti.

64 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/833,089Filed 19 Jan 2023
Priority: DE 10 2022 101 809.126 Jan 2022
Published: 15 May 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

C23C 16/52
Characterised by the method of coating: controlling or regulating the coating process
C23C 16/303
AIII BV compounds, where A is Al, Ga, In or Tl and B is N, P, As, Sb or Bi: nitrides
C23C 16/4584
The substrate being supported substantially horizontally: the substrate being rotated
C23C 16/46
Characterised by the method of coating: characterised by the method used for heating the substrate