Method and arrangement for determining the layer-thickness and the substrate temperature during coating
First Claim
1. A method for determining a thickness of a layer and a temperature of a substrate during deposition or coating of the substrate in arrangements for the manufacture of semi-conductors or in deposition-devices by use of a detected temperature radiation from the substrate when being coated, characterized in that:
- (a) the emissivity (ε
) of the substrate being coated is determined according to equation;
space="preserve" listing-type="equation">ε
=1-Rin which;
ε
represents the determined emissivity Of the substrate being coated, and R represents the reflectivity determined by measuring the reflected radiation of the substrate being coated by reflectometry;
(b) the temperature (T) of the substrate is determined according to equation;
##EQU8## in which;
T represents the determined temperature of the substrate being coated,T0 represents the initial temperature of the substrate measured by pyrometry at the beginning of the deposition or coating,P0 represents the initial thermal radiation of the substrate measured by pyrometry at the beginning of the deposition or coating,P represents the thermal radiation of the substrate being coated measured by pyrometry,R0 represents the initial reflectivity of the substrate before being coated measured by reflectometry,L0 represents the initial intensity of the reflected radiation of the substrate measured by reflectometry at the beginning of the deposition or coating,L represents the intensity of the reflected radiation of the substrate being coated measured by reflectometry,c1 and c2 each independently represent constants,λ
represents the wavelength of incident radiation comprising mono-chromatic light on the substrate being coated from a light source, andfPlanck (λ
, T0) represents Planck'"'"'s radiation formula as a function of wavelength and initial measured temperature of the substrate; and
,(c) the thickness (d) of the layer deposited or coated on the substrate is determined by comparing a measured reflectivity, determined by measuring the reflected radiation of the substrate by reflectometry, with a given reflectivity vs. layer-thickness dependence (R=f(d)).
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Abstract
The invention describes a procedure and an arrangement for measurement of temperature and thickness of layer during a deposition or coating process. As coating or depositing processes known technologies of semi-conductor manufacturing arrangements, plasma devices, ion devices, and other dry-etching arrangements may be used. The invention can also be applied to the manufacture of optical coatings. As a consequence of interference of the thermal radiation of the substrate at the growing layer, the emissivity ε changes continuously during coating or depositing, therefore, a pyrometric measurement of temperature may not be applied. This basic problem is solved by the invention, which uses a reflectometer, which determines the reflectivity R of the wafer. According to the law of conservation of energy ε=1-R so that with said reflectometer the actual emissivity of the whole (multi-layer) system may be determined. The measurement of temperature then is effected by means of a determination equation. Concurrently the thickness is determined by a comparison of the reflectometer-curve and a theoretical dependency of thickness of layer.
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Citations
9 Claims
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1. A method for determining a thickness of a layer and a temperature of a substrate during deposition or coating of the substrate in arrangements for the manufacture of semi-conductors or in deposition-devices by use of a detected temperature radiation from the substrate when being coated, characterized in that:
-
(a) the emissivity (ε
) of the substrate being coated is determined according to equation;
space="preserve" listing-type="equation">ε
=1-Rin which; ε
represents the determined emissivity Of the substrate being coated, and R represents the reflectivity determined by measuring the reflected radiation of the substrate being coated by reflectometry;(b) the temperature (T) of the substrate is determined according to equation;
##EQU8## in which;
T represents the determined temperature of the substrate being coated,T0 represents the initial temperature of the substrate measured by pyrometry at the beginning of the deposition or coating, P0 represents the initial thermal radiation of the substrate measured by pyrometry at the beginning of the deposition or coating, P represents the thermal radiation of the substrate being coated measured by pyrometry, R0 represents the initial reflectivity of the substrate before being coated measured by reflectometry, L0 represents the initial intensity of the reflected radiation of the substrate measured by reflectometry at the beginning of the deposition or coating, L represents the intensity of the reflected radiation of the substrate being coated measured by reflectometry, c1 and c2 each independently represent constants, λ
represents the wavelength of incident radiation comprising mono-chromatic light on the substrate being coated from a light source, andfPlanck (λ
, T0) represents Planck'"'"'s radiation formula as a function of wavelength and initial measured temperature of the substrate; and
,(c) the thickness (d) of the layer deposited or coated on the substrate is determined by comparing a measured reflectivity, determined by measuring the reflected radiation of the substrate by reflectometry, with a given reflectivity vs. layer-thickness dependence (R=f(d)). - View Dependent Claims (2, 3, 4, 5)
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6. An apparatus for determining a thickness of a layer and a temperature of a substrate during deposition or coating of the substrate in arrangements for the manufacture of semi-conductors or in deposition-devices by use of a detected temperature radiation from the substrate when being coated, comprising:
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(a) a first detector for measuring the intensity of the thermal radiation of a substrate in a pyrometer-branch (B); (b) a second detector for detecting reflected radiation, radiated from a source of light and reflected from the substrate in a reflectometer-branch (A); (c) at least one filter for mono-chromatizing the source of light of the reflectometer-branch (A) and the thermal radiation of the substrate; and
,(d) in which the first detector is provided with a chopper as well as with a lock-in-amplifier and the second detector is correspondingly provided with a chopper as well as with a lock-in-amplifier. - View Dependent Claims (7, 8, 9)
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Specification