Methods and apparatus for processing a substrate
Inventors
Zafar, Abdullah • Durand, William John • Chong, Xinyuan • Choi, Kenric • HU, Weize • Chan, Kelvin • Bayati, Amir • SanPedro, Michelle • Kraus, Philip A. • Allen, Adolph Miller
Assignees
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Publication Number
US-12368024-B2
Publication Date
2025-07-22
Expiration Date
Abstract
Methods and apparatus for processing a substrate are provided herein. For example, a gas supply configured for use with a processing chamber includes an ampoule that stores a precursor and comprises an input to receive a carrier gas and an output to provide a mixture of the carrier gas and the precursor to the processing chamber and a sensor assembly comprising a detector and an infrared source operably connected to an outside of an enclosure, through which the mixture flows, and a gas measurement volume disposed within the enclosure and along an inner wall thereof so that a concentration of the precursor in the mixture can be measured by the detector and transmitted to a controller.
Core Innovation
The disclosed invention relates to a gas supply configured for use with a processing chamber, where a heated enclosure houses an ampoule configured to store a precursor. The ampoule includes an input to receive a carrier gas and an output to provide a mixture of the carrier gas and the precursor through a non-dispersive infrared sensor assembly to the processing chamber. The non-dispersive infrared sensor assembly measures a concentration of the precursor in the mixture and transmits the measured concentration to a controller.
In the sensor architecture, a gas measurement volume is disposed within the heated enclosure and along an inner wall thereof, defining an infrared absorption path having a path length greater than or equal to about 38 cm. An infrared source and a detector are operably connected to, and located outside of, the heated enclosure, such that the concentration of the precursor can be measured by the detector based on the infrared absorption through the defined gas measurement volume. The approach places the infrared source and detector outside the heated enclosure while sensing through an extended absorption path.
The disclosure further refines the NDIR sensing by using a precursor detector and a reference detector together with an infrared beam splitter that splits an infrared beam into a precursor beam and a reference beam. The precursor beam is directed at the precursor detector through the gas measurement volume, while the reference beam is directed at the reference detector. The detector implementation is constrained to at least one of a thermopile sensor, a photoconductive sensor, a photovoltaic sensor, or a pyroelectric sensor, and optional optical filtering is described to differentiate infrared light that is not absorbed by any gas from infrared light absorbed by the precursor.
Claims Coverage
The partial content includes two independent claims. The inventive features center on a heated enclosure with an ampoule precursor/carrier mixing arrangement and an NDIR sensor assembly in which sensing occurs through a defined infrared absorption path inside the enclosure while the infrared source and detectors are located outside the heated enclosure.
Heated enclosure with ampoule precursor storage and mixing to processing chamber
A heated enclosure; an ampoule disposed within the enclosure configured to store a precursor, the ampoule including an input to receive a carrier gas and an output to provide a mixture of the carrier gas and the precursor through a non-dispersive infrared sensor assembly to the processing chamber.
NDIR gas measurement volume inside enclosure with extended infrared absorption path
The non-dispersive infrared sensor assembly comprising a gas measurement volume disposed within the heated enclosure and along an inner wall thereof defining an infrared absorption path having a path length greater than or equal to about 38 cm.
Outside-the-heated-enclosure infrared source and detector sending concentration to controller
A sensor assembly comprising a detector and an infrared source each operably connected to and located outside of the heated enclosure so that a concentration of the precursor in the mixture flowing through the gas measurement volume disposed within the heated enclosure can be measured by the detector and transmitted to a controller.
Precursor beam/reference beam NDIR with precursor detector and reference detector
The non-dispersive infrared sensor assembly comprising a sensor assembly comprising a precursor detector and a reference detector, an infrared beam splitter configured to split an infrared beam from an infrared source into a precursor beam and a reference beam, the precursor beam directed at the precursor detector through a gas measurement volume, wherein the gas measurement volume is disposed within the heated enclosure and along an inner wall thereof, defining an infrared absorption path having a path length greater than or equal to about 38 cm, and the reference beam directed at the reference detector.
Detector types with outside enclosure source and controller transmission
Each of the precursor detector and the reference detector comprise at least one of a thermopile sensor, a photoconductive sensor, a photovoltaic sensor, or a pyroelectric sensor and wherein the infrared source, the precursor detector, and the reference detector are operably connected to, and located outside of, the heated enclosure and configured such that a concentration of the precursor in the mixture flowing through the gas measurement volume disposed within the heated enclosure can be measured by the precursor detector and transmitted to a controller.
Across the independent claims, the core claim coverage is for a gas supply system that stores a precursor in an ampoule inside a heated enclosure, delivers a carrier gas/precursor mixture to a processing chamber, and measures precursor concentration using an NDIR sensor assembly with a gas measurement volume inside the enclosure along an inner wall and an infrared absorption path length of at least about 38 cm. One independent claim additionally requires an NDIR architecture with a beam splitter producing precursor and reference beams for corresponding precursor and reference detectors, with specified detector types and with the infrared source and detectors outside the heated enclosure.
Stated Advantages
Improved signal-to-noise ratio by locating the infrared detector outside the heated enclosure while sensing through the measurement volume inside the enclosure.
Improved accuracy through using a longer infrared absorption path length (reported up to about 5× in the described disclosure).
Documented Applications
Substrate processing using CVD or ALD in a processing chamber using the described gas supply and precursor concentration measurement.
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