MONITORING SYSTEM COMPRISING INFRARED THERMOPILE DETECTOR

• US 20070200065A1
• Filed: 10/31/2006
• Published: 08/30/2007
• Est. Priority Date: 05/08/2002
• Status: Active Grant

• Current Assignee: Entegris Incorporated
• Original Assignee: Jose Arno
• Inventors: Arno, Jose
• Granted Patent: US 7,351,976 B2
• Time in Patent Office: Days
• US Class Current: 250/343
• CPC Class Codes: G01J 3/32 Investigating bands of a spectrum in sequence by a single detector
• CPC Class Codes: G01J 3/427 Dual wavelengths spectrometry
• CPC Class Codes: G01N 2021/151 Gas blown
• CPC Class Codes: G01N 2021/8411 Application to online plant, process monitoring
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/15 Preventing contamination of the components of the optical system or obstruction of the light path
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring

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.

Claims

1. A detector system adapted for processing of a material therein, said system comprising:

a sampling region for the material;

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.

2. The detector system of claim 1, wherein the thermopile detector comprises one or more infrared radiation band pass filters that selectively transmits at least a portion of the infrared radiation characterized by a predetermined wavelength range, and wherein said predetermined wavelength range encompasses an absorption wavelength that is characteristic to said material.

3. The detector system of claim 1, wherein the thermopile detector comprises a multiple array of elements.

4. The detector system of claim 3, wherein the multiple array of elements comprises a reference element and a detector element.

5. The detector system of claim 1, wherein said infrared radiation source comprises a parabolic mirror for providing a substantially parallel beam of infrared radiation.

6. The detector system of claim 5, wherein said thermopile detector comprises a focusing lens for focusing the substantially parallel beam of infrared radiation after the transmission thereof through the sampling region.

7. The detector system of claim 1, wherein said sampling region is substantially isolated from said infrared radiation source and said thermopile detector.

8. The detector system of claim 1, wherein said sampling region comprises a part of flow circuitry through which a process gas is flowed.

9. The detector system of claim 8, wherein the infrared radiation is transmitted through said sampling region in a direction that is substantially perpendicular to the direction of the process gas flowed therethrough.

10. The detector system of claim 1, wherein a process controller receives the out put signal from the thermopile detector.

11. The detector system of claim 10, wherein the process controller comprises an integrated circuit board that is arranged in immediate signal receiving relationship with said thermopile detector for minimizing signal loss during signal transmission.

12. The detector system of claim 11, wherein said integrated circuit board is positioned adjacent to said thermopile detector.

13. The detector system of claim 1, further comprising an external heating device for heating at least a portion of the IR transmission path.

14. The detector system of claim 1, wherein said material comprises one or more components selected from the group consisting of tetraethyloxysilane, silane, silicon tetrafluoride, silicon-containing organic compounds, boranes, arsenic hydride, phosphine, hydrogen fluoride, fluorine, tungsten hexafluoride, hydrogen chloride, chlorine, titanium tetrachloride, perfluorocarbons, nitrous oxide, ammonium, hydrogen, oxygen, argon, helium, arsine, phosphine, germane, stibine, distibine, silane, substituted silanes, chlorine, bromine, organometallic precursor vapor.

15. The detector system of claim 1, wherein the material is selected from the group consisting of a solid, a liquid, a gas, a multiphase material, a multicomponent material and a supercritical media.

16. The detector system of claim 1, wherein 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 μ

m Ra to about 1.80 μ

m Ra.

17. The detector system of claim 1, wherein said sampling region is isolated from said infrared radiation source and said thermopile detector with interfacial spaces therebetween, and wherein a purge gas is provided at said interfacial spaces for removing particles contained by said material and preventing particle deposition thereat.

18. The detector system of claim 1, further comprising at least one sensor arranged to sense a characteristic of the material.

20. A method of manufacturing a semiconductor device comprising operating a semiconductor process including processing of or with a material, and monitoring and/or controlling said process using the detector system of claim 1.

19. The detector system of claim 19, wherein the characteristic is selected from the group consisting of composition, concentration, flow rate, pressure and temperature.