Split valve air curtain
Contamination from outgassing during a deposition process is addressed by a series of equipment enhancements, including throttle valves, a dual air curtain, and a residual gas analysis (RGA) monitor. The dual air curtain can be configured to flow a first gas during wafer processing and a second gas during wafer unloading, to re-direct and capture outgassed species. The dual air curtain and the throttle valves can be programmed in an automated feedback control system that utilizes data from the RGA monitor.
1. A system, comprising:
a wafer station;
a load lock adjoining the wafer station, the load lock configured to alternate between atmospheric pressure and vacuum;
a buffer chamber adjoining the load lock;
a vacuum chamber adjoining the buffer chamber and comprising a showerhead and a slit valve, the vacuum chamber configured to expose a wafer to gas phase reactants from the showerhead; and
a dual air curtain between the slit valve and the showerhead and configured to flow a plurality of gases.
2. The system of claim 1 , wherein the vacuum chamber further comprises a chuck.
3. The system of claim 1 , wherein the vacuum chamber is configured to perform one or more of a chemical vapor deposition (CVD) process, a plasma enhanced chemical vapor deposition (PECVD) process, an atomic layer deposition (ALD) process, and a spatial atomic layer deposition (SALD) process.
4. The system of claim 1 , wherein the plurality of gases includes one or more of argon, nitrogen, oxygen, and helium.
5. The system of claim 1 , further comprising a chamber throttle valve configured to regulate a pressure of the vacuum chamber.
6. The system of claim 1 , further comprising a buffer chamber throttle valve configured to regulate a pressure of the buffer chamber.
7. The system of claim 1 , further comprising a residual gas analysis (RGA) monitor configured to measure composition of residual gases in one or more of the vacuum chamber and the buffer chamber.
8. The system of claim 7 , further comprising a controller configured to regulate one or more of gas pressure and gas flow based on measurements performed by the RGA monitor.
9. The system of claim 8 , wherein the controller is configured to regulate the one or more of gas pressure and gas flow based on one or more of a failure data collection (FDC) monitor, data stored on a tool server, and a statistical process control (SPC) monitor.
10. The system of claim 8 , wherein the controller is configured to control the dual air curtain to:
flow a first gas while the wafer is exposed to the gas phase reactants in the vacuum chamber and the slit valve is closed; and
flow a second gas while the wafer is being transferred out of the vacuum chamber and the slit valve is open.