Monitoring system comprising infrared thermopile detector
AssigneeAdvanced Technology Materials, Inc.
InventorJose I. Arno
Life of this patent
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Abstract
The present invention relates to a semiconductor processing system that employs infrared-based thermopile detector for process control, by analyzing a material of interest, based on absorption of infrared light at a characteristic wavelength by such material. Specifically, an infrared light beam is transmitted through a linear transmission path from an infrared light source through a sampling region containing material of interest into the thermopile detector. The linear transmission path reduces the risk of signal loss during transmission of the infrared light. The transmission path of the infrared light may comprise a highly smooth and reflective inner surface for minimizing such signal loss during transmission.
Claims25
A detector system adapted for processing of a material therein, said system comprising:
- a sampling region for the material, the material comprising a first gas;
- an infrared radiation source constructed and arranged to transmit infrared radiation through the sampling region;
- and
- a thermopile detector constructed and arranged to receive infrared radiation after the transmission thereof through the sampling region and to responsively generate an output signal correlative of said material within the sampling region;
- wherein the infrared radiation is transmitted along a transmission path that is substantially linear, and wherein said infrared radiation source and said thermopile detector are aligned along the transmission path of said infrared radiation;
- and
- wherein the system is characterized by any of the following:
- (a) a process controller receives the output signal from the thermopile detector;
- (b) a heating element distinct from said infrared radiation source is adapted to heat at least a portion of the transmission path;
- (c) said transmission path comprises an inner surface characterized by a roughness in a range of from about 0.012 μm Ra to about 1.80 μm Ra;
- and
- (d) at least one gas introduction element is arranged to introduce a second gas between the infrared radiation source and the thermopile detector.
A detector system adapted for processing therein a material comprising a first gas, the system comprising:
- a sampling region for the material, the sampling region defining a radiation transmission path;
- an infrared radiation source constructed and arranged to emit infrared radiation into the sampling region;
- and
- a thermopile detector constructed and arranged to receive at least a portion of said infrared radiation following passage thereof through the sampling region, and arranged to responsively generate an output signal correlative of said material;
- wherein the system is further characterized by any of the following:
- (a) at least one gas introduction element is arranged to introduce a second gas between the infrared radiation source and the thermopile detector;
- (b) the radiation transmission path comprises an inner surface having a roughness in a range of from 0.012 μm Ra to 1.80 μm Ra;
- and
- (c) a heating element distinct from the infrared radiation source is adapted to heat at least a portion of the radiation transmission path.
A method of operating a semiconductor process including processing of or with a material comprising a first gas, said method comprising emitting infrared radiation generated by an infrared radiation source into a sampling region defining a radiation transmission path and containing said material, receiving at least a portion of said emitted infrared radiation with a thermopile detector, generating an output from said thermopile detector indicative of presence or concentration of a desired component of said material, and controlling one or more conditions in and/or affecting the semiconductor process in response to said output, wherein the method is further characterized by any of the following:
- (a) a second gas is flowed through at least one gas introduction element and introduced between the infrared radiation source and the thermopile detector;
- (b) said infrared radiation is transmitted along a transmission path that comprises an inner surface characterized by a roughness in a range of from about 0.012 μm Ra to about 1.80 μm Ra;
- and
- (c) at least a portion of said radiation transmission path is heated by a heating element that is distinct from the infrared radiation source.
Dependencies are inferred from the claim text.