US-12624452-B2 - Systems and methods of controlling gas flows in semiconductor processing systems

Abstract

A gas system includes an enclosure, a process gas metering valve, a shutoff valve, and a flow switch. The process gas metering valve arranged within the enclosure to flow a process gas to a process chamber of a semiconductor processing system. The shutoff valve is connected to the process gas metering valve to fluidly separate the process gas metering valve from a process gas source. The flow switch is operably connected to the shutoff valve to cease flow of the process gas to the process chamber of the semiconductor processing system using the shutoff valve according to flow of a gas traversing the flow switch. Semiconductor processing systems, gas control methods, and gas system kits are also described.

Inventors

• Mark Fessler
• Glenn Holbrook

Assignees

• ASM IP HOLDING B.V.

Dates

Publication Date

20260512

Application Date

20220523

Claims (17)

1. 1 . A gas system, comprising: an enclosure; a process gas source fluidly coupled to a process gas conduit; an inert gas source fluidly coupled to an inert gas conduit wherein the process gas conduit and the inert gas conduit do not intersect; a process gas metering valve arranged within the enclosure and configured to flow a process gas from the process gas source to a process chamber of a semiconductor processing system; a shutoff valve connected to the process gas metering valve and configured to fluidly separate the process gas metering valve from the process gas source; and a flow switch operably connected to the shutoff valve and configured to provide a shutoff signal according to a flow of an inert gas from the inert gas source traversing the flow switch, wherein the shutoff valve is configured to cease the flow of the process gas to the process chamber of the semiconductor processing system in response to the shutoff signal, wherein the flow switch has a shutoff trigger, wherein the process gas metering valve has a flow rating, and wherein the shutoff trigger of the flow switch is less than the flow rating of the process gas metering valve.
2. 2 . The gas system of claim 1 , wherein at least one of the shutoff valve and the flow switch are arranged outside of the enclosure.
3. 3 . The gas system of claim 1 , wherein the flow switch is fluidly isolated from the shutoff valve.
4. 4 . The gas system of claim 1 , further comprising a relay connecting the flow switch to the shutoff valve.
5. 5 . The gas system of claim 1 , further comprising a controller connecting the flow switch to the shutoff valve.
6. 6 . The gas system of claim 1 , wherein the process gas source is a first process gas source, the flow switch is a first process gas flow switch, and the shutoff valve is a first shutoff valve, the gas system further comprising: a second process gas source; a second process gas flow switch connected to the second process gas source; and a second shutoff valve connected to the second process gas flow switch and fluidly coupling the second process gas source to the process chamber, wherein the second process gas flow switch is operably connected to the second shutoff valve.
7. 7 . The gas system of claim 1 , further comprising: a foreline connected to the process chamber; a vacuum pump connected to the foreline; an inert gas flow switch connected to the vacuum pump; and the inert gas source connected to the inert gas flow switch and fluidly coupled therethrough to the vacuum pump, wherein the inert gas flow switch is operably connected to the shutoff valve.
8. 8 . The gas system of claim 1 , wherein the flow switch is an inert gas flow switch, the gas system further comprising: a vacuum pump connected to the process chamber; and the inert gas source connected to the inert gas flow switch and fluidly coupled therethrough to the vacuum pump while bypassing the process chamber.
9. 9 . The gas system of claim 8 , wherein the inert gas flow switch has an inert gas shutoff trigger, and wherein the inert gas flow switch is configured to close the shutoff valve when the flow of the inert gas from the inert gas source to the vacuum pump is less than the inert gas shutoff trigger.
10. 10 . The gas system of claim 1 , further comprising: a foreline fluidly coupled to the process gas metering valve; a vacuum pump connected to the foreline; and an process gas flow switch fluidly coupled to the process gas conduit, wherein the process gas flow switch is operably connected to the shutoff valve.
11. 11 . The gas system of claim 10 , wherein the process gas flow switch has a process gas shutoff trigger, and wherein the process gas flow switch is configured to close the shutoff valve when a flow of the process gas traversing the process gas flow switch is less than the process gas shutoff trigger.
12. 12 . The gas system of claim 10 , wherein the flow switch is a first inert gas flow switch, the gas system further comprising: an exhaust conduit connected to the vacuum pump; and a second inert gas flow switch fluidly coupled to the exhaust conduit and therethrough to the vacuum pump, wherein the second inert gas flow switch is operably connected to the flow switch.
13. 13 . A semiconductor processing system, comprising: a gas system as recited in claim 1 , wherein the flow switch is an inert gas flow switch, wherein the shutoff trigger is an inert gas shutoff trigger a substrate support arranged within the process chamber and configured to seat thereon a substrate during deposition of a film onto the substrate using the process gas provided by the process gas source.
14. 14 . The gas system of claim 1 , further comprising a controller configured to: operably connect the flow switch and the shutoff valve; and in response to the shutoff signal, close the shutoff valve.
15. 15 . The gas system of claim 1 , further comprising a relay configured to: operably connect the flow switch and the shutoff valve; and in response to the shutoff signal, close the shutoff valve.
16. 16 . The gas system of claim 1 , wherein the shutoff valve is configured to receive the shutoff signal.
17. 17 . The gas system of claim 16 , further comprising at least one of a controller or a relay, and wherein the at least one of a controller or a relay is configured to: receive the shutoff signal from the flow switch; and provide the shutoff signal to the shutoff valve.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63/193,372, filed on May 26, 2021, in the United States Patent and Trademark Office, the disclosure of which is incorporated herein in its entirety by reference. FIELD OF INVENTION The present disclosure generally relates to controlling gas flows in semiconductor processing systems, and more particularly to controlling hazardous process gas flows in semiconductor processing systems. BACKGROUND OF THE DISCLOSURE Process tools used to fabricate semiconductor devices employ process gases to perform various process operations during the fabrication of semiconductor devices, such as to deposit films onto substrates during the fabrication of very large-scale integration circuit devices, solar cells, and displays. The process gases generally flow from a process gas source to the process tool through a metering device, which regulates flow of process gas according to the processing requirements of the process tool employing the process gas. During processing, the process tool typically issues an exhaust flow, which may include residual process gas and/or various process gas products. Since residual process gas and/or various process gas products may be hazardous, e.g., flammable and/or toxic, inert gases may be intermixed with the residual process gas products and/or process gas products to limit (or eliminate) potential hazards otherwise associated with the residual process gas and/or process gas products exhausted by the process tool. One challenge to intermixing inert gases into exhaust flows is the cost associated with certain inert gases. For example, to ensure that concentration of potentially hazardous compounds in the exhaust flow is sufficiently low, flow (e.g., mass flow or volumetric flow) of the inert gas provided to the process tool may be sized in view of the largest flow rate of process gas provided to the process tool, such as in the event that the process gas supply valve is inadvertently driven to a fully open position. While generally satisfactory insofar that the flow rate of inert gas is sufficient to reduce hazards associated with relatively high flow rates of residual process gas and/or process gas products, the strategy also means that the inert gas flow rate is routinely greater than that required by the process employed by the process tool. This increases operating costs of the process tool due to inert gas consumption. It also requires that certain process tool accessories, such as ventilation systems and/or exhaust abatement systems, be larger than otherwise possible. One approach to limiting cost associated with inert gas is to employ a flow restrictor or flow rate governor into the process gas supply line. Flow restrictors and flow rate governors may be employed to limit process gas flows to process tools from the source side (e.g., from the house or bulk supply of a process gas) when sized to be smaller than the flow rating of the process gas valve and larger than the process flow required by the process tool. However, while effective in limiting the inert gas requirements of the process tool, flow restrictors and flow rate governors are typically also oversized with respect to the process gas flow required by the process tool. Accordingly, the flow rate of inert gas provided to the process tool is still higher than otherwise required by the process tool, operating costs of the process tool due to inert gas requirements being higher than otherwise required. Such systems and methods have generally been acceptable for their intended purpose. However, there remains a need for improved gas systems, semiconductor processing systems with gas system, and methods of controlling process gas flows in semiconductor processing systems. The present disclosure provides a solution to this need. SUMMARY OF THE DISCLOSURE A gas system is provided. The gas system includes an enclosure, a process gas metering valve, a shutoff valve, and a flow switch. The process gas metering valve is arranged within the enclosure and is configured to flow a process gas to a process chamber of a semiconductor processing system. The shutoff valve is connected to the process gas metering valve and is configured to fluidly separate the process gas metering valve from a process gas source. The flow switch is operably connected to the shutoff valve and configured to cease flow of the process gas to the process chamber of the semiconductor processing system using the shutoff valve according to flow of a gas traversing the flow switch. In addition to one or more of the features described above, or as an alternative, further examples may include that at least one of the shutoff valve and the flow switch are arranged outside of the enclosure. In addition to one or more of the features described above, or as an alternative, further examples may include that the flow switch is fluidly coupled to the shutoff valve and the