Method and system to measure flow velocity and volume
Systems, devices and methods of measuring a flow of a liquid stream for a semiconductor process are provided. The liquid stream is delivered through a liquid delivery nozzle. The nozzle is adapted to deliver the liquid stream for the semiconductor process. The free stream extends from an upstream location near the nozzle to a downstream location. The stream is marked at the upstream location and measured at the downstream location to determine the flow.
1. A method of measuring a flow of a liquid stream for a semiconductor process, the method comprising:
delivering the stream through a liquid delivery nozzle, the nozzle adapted to deliver liquid for the semiconductor process, the stream extending from an upstream location to a downstream location beyond the nozzle;
marking the stream at the upstream location;
measuring the stream at the downstream location to determine the flow, and
projecting a light beam toward the stream to determine the flow of the stream with light traveling past the stream at the downstream location.
2. The method of claim 1 wherein the stream exits the nozzle and the stream comprises a free stream extending from the nozzle to the downstream location.
3. The method of claim 1 wherein the flow of the stream comprises at least one of a flow velocity, a flow volume per unit time, or a total flow volume delivered with the stream.
4. The method of claim 1 wherein a size of the stream is measured over time to determine at least one of the size of the stream over time, regularity of the size of the stream over time, gas bubbles in the stream or drops in the stream, and wherein the semiconductor process liquid is applied to the substrate in response to the size of the stream over time.
5. The method of claim 1 wherein measuring the stream comprises determining at least one of a position or a phase of the stream at the downstream location.
6. The method of claim 5 wherein the phase of the stream correlates with a velocity of the stream.
7. The method of claim 1 wherein marking the stream comprises moving the stream transverse to the flow.
8. The method of claim 7 wherein marking the stream comprises moving the stream from a first position to a second position transverse to the flow.
9. The method of claim 1 wherein measuring comprises determining a size of the stream at the downstream location, and wherein at least one of a velocity or a phase of the stream are combined with the size to determine the flow volume and/or flow volume per unit time of the stream.
10. The method of claim 9 wherein the size of the stream comprises at least one of a diameter, a width, a circumference or a cross-sectional area of the stream at the downstream location.
11. The method of claim 1 further comprising:
measuring the stream at the upstream location; and
comparing the stream at the upstream location to the stream at the downstream location to determine at least one of a phase or a velocity of the stream.
12. The method of claim 11 further comprising projecting an upstream light beam toward the stream at the upstream location to determine the flow.
13. The method of claim 1 further comprising determining a diameter of the stream;
calculating a cross sectional area of the stream from the diameter; and
integrating the cross sectional area and a velocity to determine a volume per unit time.
14. The method of claim 13 wherein the velocity comprises an average velocity and the cross sectional area comprises an average cross sectional area.