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US 2017/0248528 A1Published application
System for measuring levels of radiation reflecting from semiconductor material for use in measuring the dopant content thereof
AssigneeAurora Solar Technologies (Canada) Inc.
InventorStephen Warren BLAINE
Life of this patent
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Abstract
A system and method of non-contact measurement of the dopant content of semiconductor material by reflecting infrared (IR) radiation off of the material into an integrating sphere to scatter the received radiation and passing portions of the radiation through band pass filters of differing wavelength ranges, comparing the level of energy passed through each filter and calculating the dopant content by referencing a correlation curve made up of known wafer dopant content for that system.
Claims29
A system for measuring levels of radiation reflected from semiconductor material for use in measuring the dopant content of the material, comprising:
- a) an infrared radiation source;
- b) a modulator for modulating the radiation from the infrared radiation source;
- c) an integrating sphere having a first opening for receiving the modulated radiation from the source and a second opening for receiving radiation reflected from the material, the sphere configured to scatter the received radiation reflected from the material within the sphere;
- d) a collimator configured to direct the radiation from the infrared radiation source through the sphere to impact the material at an angle from the normal with reference to the material, the angle sufficient to minimise radiation from being reflected directly back to the collimator and also to minimise radiation entering the sphere before reflecting from the material;
- e) a first baffle positioned within the sphere to prevent the received radiation reflected from the material from travelling to the first band pass filter without first scattering within the sphere;
- f) a second baffle positioned within the sphere to prevent the received radiation reflected from the material from travelling to the second band pass filter without first scattering within the sphere;
- g) a first band pass or edge pass filter positioned to receive a first portion of the received radiation reflected from the material, the first band pass or edge pass filter configured to pass a limited wavelength band of infrared radiation from within the overall spectrum emitted by the infrared radiation source through the first filter;
- h) a second band pass or edge pass filter positioned to receive a second portion of the received radiation reflected from the material, the second band pass or edge pass filter configured to pass a limited wavelength band of infrared radiation from within the overall spectrum emitted by the infrared radiation source through the second filter, wherein the limited wavelength band that is passed by the second filter is different as compared to the limited wavelength band passed by the first filter;
- i) a first radiation detector positioned to receive the radiation that passes the first filter and configured to determine a first level of energy;
- and
- j) a second radiation detector positioned to receive the radiation that passes the second filter and configured to determine a second level of energy.
8 more elements
A system for measuring levels of radiation reflected from semiconductor material for use in measuring the dopant content of the material, comprising:
- a) a source of collimated infrared radiation;
- b) a modulator for modulating the radiation from the infrared radiation source;
- c) an integrating sphere having a first opening for receiving the modulated radiation from the source and a second opening for receiving radiation reflected from the material, the sphere configured to scatter the received radiation reflected from the material within the sphere;
- d) a first baffle positioned within the sphere to prevent the received radiation reflected from the material from travelling to the first band pass filter without first scattering within the sphere;
- e) a second baffle positioned within the sphere to prevent the received radiation reflected from the material from travelling to the second band pass filter without first scattering within the sphere;
- f) a first band pass or edge pass filter positioned to receive a first portion of the received radiation reflected from the material, the first filter configured to pass a limited wavelength band of infrared radiation from within the overall spectrum emitted by the infrared radiation source through the first filter;
- g) a second band pass or edge pass filter positioned to receive a second portion of the received radiation reflected from the material, the second band pass filter configured to pass a limited wavelength band of infrared radiation from within the overall spectrum emitted by the infrared radiation source through the second filter, wherein the limited wavelength band that is passed by the second filter is different as compared to the limited wavelength band passed by the first filter;
- h) a first radiation detector positioned to receive the radiation that passes the first band pass filter and configured to determine a first level of energy;
- and
- i) a second radiation detector positioned to receive the radiation that passes the second filter and configured to determine a second level of energy;
- wherein the source of collimated infrared radiation is configured to direct the radiation through the sphere to impact the material at an angle from the normal with reference to the material, the angle sufficient to minimise radiation from being reflected directly back to the collimator and also to minimise radiation entering the sphere before reflecting from the material.
8 more elements
Dependencies are inferred from the claim text.