System and method for detecting liquid flow from a nozzle in a semiconductor processing device

• US 7,233,015 B2
• Filed: 11/04/2004
• Issued: 06/19/2007
• Est. Priority Date: 11/04/2004
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Roberts, Kenneth L.
• Primary Examiner(s): Epps; Georgia
• Assistant Examiner(s): Ko; Tony
• Application Number:
  US10/983,007
• Publication Number:
  US 20060091335A1
• Time in Patent Office: 957 Days
• Field of Search: 250/227.11, 250573-576, 356/436, 137/487.5, 73/13.1, 73/17.4, 73/36, 732/93, 732/94, 738/61, 340/603, 340/606, 340/618, 340/619
• US Class Current: 250/573
• CPC Class Codes: G01N 21/59 Transmissivity G01N21/25 takes precedence
• CPC Class Codes: G01V 8/16 using optical fibres

Abstract

A system for detecting liquid flow from a nozzle in a semiconductor processing device includes a first fiber optic sensor, a second fiber optic sensor, and an amp. The first fiber optic sensor and second fiber optic sensor are located on opposite sides of at least one nozzle. The first fiber optic sensor transmits light, and the second fiber optic sensor receives more of the light when the nozzle is not dispensing liquid than when the nozzle is dispensing liquid. The amp is coupled to the first fiber optic sensor and second fiber optic sensor. The amp indicates whether the nozzle is dispensing liquid according to an amount of the light received at the second fiber optic sensor.

Claims

1. A system for detecting liquid flow from a nozzle in a semiconductor processing device, comprising:

a first fiber optic sensor and a second fiber optic sensor located on opposite sides of at least one nozzle, the first fiber optic sensor operable to transmit light, the second fiber optic sensor operable to receive more of the light when the nozzle is not dispensing liquid than when the nozzle is dispensing liquid; and

an amp coupled to the first fiber optic sensor and second fiber optic sensor and operable to indicate whether the nozzle is dispensing liquid according to an amount of the light received at the second fiber optic sensor.

2. The system of claim 1, wherein the amp is further operable to generate a first current if the amount of the light received at the second fiber optic sensor indicates that the nozzle dispensing the liquid and operable to generate a second current if the amount of the light receive at the second fiber optic sensor indicates that the nozzle is not dispensing the liquid.

3. The system of claim 1, wherein the amp is operable to generate a current according to the amount of the light received by the second fiber optic sensor, the amp operable to generate more current in response to the second fiber optic sensor receiving a greater percentage of the light transmitted from the first fiber optic sensor.

4. The system of claim 3, wherein a decrease in the current over a short period of time may indicate that the nozzle is dripping the liquid.

5. The system of claim 1, wherein the amp is further operable to generate a first voltage if the amount of the light received at the second fiber optic sensor indicates that the nozzle dispensing liquid and operable to generate a second voltage if the amount of the light received at the second fiber optic sensor indicates that the nozzle is not dispensing liquid.

6. The system of claim 1, wherein the amp is further operable to generate a voltage according to the amount of the light received by the second fiber optic sensor, the amp operable to generate more voltage in response to the second fiber optic sensor receiving a greater percentage of the light transmitted from the first fiber optic sensor.

7. The system of claim 6, wherein a decrease in the voltage over a short period of time may indicate that the nozzle is dripping the liquid.

8. The system of claim 1, further comprising a processing module operable to determine whether the nozzle is dispensing the liquid when the nozzle is programmed not to dispense the liquid and to generate a notification in response to determining that the nozzle is dispensing the liquid when the nozzle is programmed not to dispense the liquid.

9. The system of claim 1, further comprising a processing module operable to determine whether the nozzle is not dispensing the liquid when the nozzle is programmed to dispense the liquid and to generate a notification in response to determining that the nozzle is dispensing the liquid when the nozzle is programmed not to dispense the liquid.

10. The system of claim 1, further comprising a processing module operable to determine whether the nozzle is dispensing the liquid and to store data indicating whether the nozzle is dispensing the liquid.