In-situ apparatus for detecting abnormality in process tube

Abstract

A process tube device can detect the presence of any external materials that may reside within a fluid flowing in the tube. The process tube device detects the external materials in-situ which obviates the need for a separate inspection device to inspect the surface of a wafer after applying fluid on the surface of the wafer. The process tube device utilizes at least two methods of detecting the presence of external materials. The first is the direct measurement method in which a light detecting sensor is used. The second is the indirect measurement method in which a sensor utilizing the principles of Doppler shift is used. Here, contrary to the first method that at least partially used reflected or refracted light, the second method uses a Doppler shift sensor to detect the presence of the external material by measuring the velocity of the fluid flowing in the tube.

1 . (canceled) 
     
     
         2 . A method of detecting external materials inside a fluid flowing within a tube comprising:
 emitting a laser beam into the fluid from a light emitting source on a first side of the tube;   passing the laser beam through the fluid along a first optical path, the first optical path being a substantially linear path;   receiving the laser beam at a first sensor on a second side of the tube opposing the light emitting source;   receiving a refracted portion of the laser beam at a second sensor positioned on the second side of the tube and adjacent to the first sensor, the refracted portion of the laser beam propagating along a second optical path different from the first optical path;   determining at least one external material is present in the fluid in response to the second sensor receiving the refracted portion of the laser beam; and   determining no external material is present in the fluid passing between the light emitting source and the first sensor in response to the first sensor receiving the light along the first optical path.   
     
     
         3 . The method of  claim 2 , further comprising:
 receiving the refracted portion of the laser beam at a third sensor on the first side of the tube and adjacent to the light emitting source; and   determining at least one external material is present in the fluid in response to the refracted portion of the laser beam propagating along a second optical path and received at the third sensor.   
     
     
         4 . The method of  claim 3 , wherein the external material includes at least one of air, a bubble, a void, debris, or a particle. 
     
     
         5 . A process tube device, comprising:
 a nozzle configured to receive fluid;   a main tube coupled to the nozzle, the main tube providing a channel for the fluid, the main tube having a first side and a second side opposite of the first side;   a light emitting source adjacent to the first side of the main tube, the light emitting source configured to emit light to the channel along a first optical path;   a first sensor positioned on the second side of the main tube opposite of the light emitting source, wherein the first sensor is configured to receive the light emitted by the light emitting source along the first optical path, wherein the first optical path is substantially linear from the light emitting source to the first sensor;   a second sensor positioned on the second side of the first tube and adjacent to the first sensor;   a third sensor positioned on the first side of the first tube and adjacent to the light emitting source;   a fourth sensor positioned on the first side of the first tube and adjacent to the third sensor;   a controller operatively coupled to the first, second, third, and fourth sensors and configured to receive data from the first, second, third, and fourth sensors, wherein the first, second, third, and fourth sensors receive signals based on the light from the light emitting source,   wherein the controller is further configured to:
 determine at least one external material is present in fluid within the main tube in response to light emitted from the light emitting source being refracted from the at least one external material, propagated along a second optical path and received at the second sensor, wherein the second optical path is different from the first optical path; and 
   determine no external material is present in the fluid passing between the light emitting source and the first sensor in response to the first sensor receiving the light along the first optical path,   wherein the light emitting source faces the first sensor and fully overlaps with the first sensor in a first direction,   wherein the light emitting source is spaced apart from the second sensor and does not overlap with the second sensor in the first direction,   wherein the light emitting source overlaps with the third sensor in a second direction transverse to the first direction, and   wherein the fourth sensor does not overlap with the second sensor in the first direction.   
     
     
         6 . The process tube device of  claim 5 ,
 wherein the controller is further configured to:
 determine at least one external material is present in the fluid in response to light emitted from the light emitting source being reflected from the at least one external material, propagated along a second optical path and received at the third sensor. 
   
     
     
         7 . The process tube device of  claim 5 ,
 wherein the controller is further configured to:
 determine at least one external material is present in the fluid in response to light emitted from the light emitting source being reflected from the at least one external material, propagated along a third optical path and received at the fourth sensor, the third optical path being different from the first and second optical paths. 
   
     
     
         8 . The process tube device of  claim 5 , wherein the light emitting source includes a laser beam. 
     
     
         9 . The process tube device of  claim 5 , further comprising
 a first tube extended from the main tube, the first tube having a first side and a second side opposite of the first side, wherein the first tube includes a linear section and a non-linear section adjacent to the linear section.   
     
     
         10 . The process tube device of  claim 9 , wherein the linear section includes a substantially straight tube throughout the linear section and the non-linear section includes at least one of a V-shaped tube or an L-shaped tube or a U-shaped tube. 
     
     
         11 . The process tube device of  claim 10 , wherein the linear section of the first tube is located between the non-linear section and the main tube. 
     
     
         12 . The process tube device of  claim 11 , further comprising:
 a first light emitting source on the first side of the first tube;   a second light emitting source on the first side of the first tube and adjacent to the first light emitting source; and   a Doppler shift sensor on the second side of the first tube, the Doppler shift sensor positioned opposite of a location between the first and second light emitting sources.   
     
     
         13 . The process tube device of  claim 12 , wherein the first and second light emitting sources include a laser beam, wherein the Doppler shift sensor includes a laser Doppler anemometry configured to use Doppler shift in a laser beam to measure a velocity in fluid flows. 
     
     
         14 . The process tube device of  claim 13 , wherein the controller is operatively coupled to the Doppler shift sensor and configured to receive velocity data from the Doppler shift sensor, wherein the Doppler shift sensor generates the velocity data based on the light from the first and second light emitting sources,
 wherein the controller is further configured to:
 determine at least one external material is present in fluid in the first tube in response to the Doppler shift sensor outputting no velocity reading for the fluid in the first tube passing between the first and second light emitting sources and the Doppler shift sensor; and 
 determine no external material is present in the fluid in the second tube passing between the first and second light emitting sources and the Doppler shift sensor in response to a velocity of the fluid in the first tube maintaining a substantially constant velocity. 
   
     
     
         15 . The process tube device of  claim 14 , wherein the external material includes at least one of air, a bubble, a void, debris, or a particle. 
     
     
         16 . A fluid inspecting system for inspecting flowing fluid, comprising:
 a process tube device, including:
 a nozzle configured to receive fluid; 
 a main tube coupled to the nozzle, the main tube providing a channel for the fluid; 
 a first tube extending from the main tube, the first tube having a first side and a second side opposite of the first side; 
 a light emitting source adjacent to the first side of the first tube, the light emitting source configured to emit light to the channel along a first optical path; 
 a first sensor positioned on the second side of the first tube opposite of the light emitting source, wherein the first sensor is configured to receive the light emitted by the light emitting source along the first optical path, wherein the first optical path is substantially linear from the light emitting source to the first sensor; 
 a second sensor positioned on the second side of the first tube and adjacent to the first sensor; 
 a third sensor positioned on the first side of the first tube and adjacent to the light emitting source; 
 a fourth sensor positioned on the first side of the first tube and adjacent to the third sensor; and 
 a controller operatively coupled to the first, second, third, and fourth sensors and configured to receive data from the first, second, third, and fourth sensors, wherein the first, second, third, and fourth sensors receive signals based on the light from the light emitting source, 
   wherein the controller is further configured to:
 determine at least one external material is present in fluid within the first tube in response to light emitted from the light emitting source being refracted from the at least one external material, propagated along a second optical path and received at the second sensor, wherein the second optical path is different from the first optical path; and 
   determine no external material is present in the fluid passing between the light emitting source and the first sensor in response to the first sensor receiving the light along the first optical path,   wherein the light emitting source faces the first sensor and fully overlaps with the first sensor in a first direction,   wherein the light emitting source is spaced apart from the second sensor and does not overlap with the second sensor in the first direction,   wherein the light emitting source overlaps with the third sensor in a second direction transverse to the first direction,   wherein the light emitting source overlaps with the fourth sensor in the second direction, and   wherein the fourth sensor on the first side does not overlap with either the first sensor or the second sensor on the second side in the first direction.   
     
     
         17 . The fluid inspecting system of  claim 16 , wherein the controller is further configured to:
 determine at least one external material is present in the fluid in response to light emitted from the light emitting source being reflected from the at least one external material, propagated along a second optical path and received at the third sensor.   
     
     
         18 . The fluid inspecting system of  claim 16 , wherein the controller is further configured to:
 determine at least one external material is present in the fluid in response to light emitted from the light emitting source being reflected from the at least one external material, propagated along a third optical path and received at the fourth sensor, the third optical path being different from the first and second optical paths.   
     
     
         19 . The fluid inspecting system of  claim 16 , further comprising
 a second tube extended from the main tube, the second tube adjacent to the first tube and having a first side and a second side opposite of the first side, wherein the second tube includes a linear section and a non-linear section adjacent to the linear section.   
     
     
         20 . The fluid inspecting system of  claim 19 , wherein the linear section includes a substantially straight tube throughout the linear section and the non-linear section includes at least one of a V-shaped tube or an L-shaped tube or a U-shaped tube, and
 wherein the linear section of the second tube is located between the non-linear section and the main tube.   
     
     
         21 . The fluid inspecting system of  claim 18 , wherein the external material includes at least one of air, a bubble, a void, debris, or a particle.