RGA Filament Control Schemes

Transcript RGA Filament Control Schemes

Automation of RGAs and Sensors for FDC of PVD Metal Thin Film Processing

Arif Choudhury 1 ,

Eric McCormick 1

, Guy Takayesu 1 , Keith Han 3 , Alex Lee 3 , Young Hwan Lee 3 , Justin Wong 2 , and John Yoo 2 1 TriQuint Semiconductor Corporation, 500 W Renner Rd, Richardson, Texas, USA 75080 2 BISTel America, 4633 Old Ironsides Dr, Suite 300, Santa Clara, CA 95054 3 BISTel Inc. 2F, Jeongpung Bldg, 1341-3 Seocho-dong, Seocho-gu, Seoul, Korea 137-070 © 2013 TriQuint Semiconductor, Inc.

Content

• Introduction – RGA Usage In PVD Process • Applications of RGA in Manufacturing • Architecture of FDC and Sensors • RGA Filament Control Schemes • Examples of FDC with RGA • Future Work • Conclusion © 2013 TriQuint Semiconductor, Inc.

Introduction of RGA and RGA Usage in PVD

• The RGA is commonly used to identify atomic and molecular species in a high vacuum environment.

• In the PVD process the RGA is commonly used to monitor contamination before and during the process.

Pressure Range of PVD Process

• Various Vacuum Mediums* * http://www.eng.tau.ac.il/~yosish/courses/vlsi.html

RGA Advantage

• The RGA is an ideal tool for monitoring of PVD process because it can detect subtle changes in the chamber condition, i.e. contamination • The mean free path increases at high vacuum so the probability of detecting a contaminant goes up.

• Can report the probable species of molecule present in the PVD chamber.

• Possible real time detection of contaminants or chamber leaks.

• Not reliant on metrology feedback.

Applications of RGA in Manufacturing

• Baseline Spectrum – Spectrum scan of a known good chamber or condition • Spectrum Analysis (Troubleshooting) – Analyzing the species that exist inside a chamber that is having some unknown issue • He Leak Checking – Standard practice after a PVD target change • Stand Alone Process Analysis – The RGA manufacturers offer stand alone packages for near real time analysis of spectrum as the tool is running.

– Typically not integrated into the house FDC system.

– High cost for the software.

Benefits of Integrating RGA with FDC

 Having one system that can connect to multiple components and interdict in the event of an incident saves the expense of having multiple FDC systems for each component  Adding RGAs from different manufacturers that are not supported by the tool OEMs.

Architecture of FDC and Sensors

FDC Pump Y-TAP Chamber Processing Status RGA Application RGA Control Libraries RF Application RF Data Collection Library

•

Wafer Processing Status of Each Chamber

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Trace Data PM1 PVD Controller PM6 RF PM2 PM5 Pump Application Pump Data Collection Library PM3 PM4 Pump

Component Connections

• Tool SVIDs  HSMS Ethernet • RF Monitor  A to D device to receive the analog signals and pass them to the Ethernet • Pump data  convertor RS-232 hub to Ethernet • Others?

What is Gained?

• Context for sensors that are not available on processing chambers.

RGA Filament Control Schemes

• RGA operation constraint – Open Ion Source mode of RGA operation – RGA operating pressure region is limited – Filament tripped off when P > 9.0 x 10 -3 Torr • Customized RGA filament control schemes – P < 9.0 x 10 -3 Torr, filament is always on – P > 9.0 x 10 -3 Torr, filament on only for a short time (10sec.) at end of wafer process, otherwise filament is off © 2013 TriQuint Semiconductor, Inc.

Real time control with integrated sensors like the RGA

Chamber Pressure Filament Status (On) •Example of RGA control to sample at the end of a process run.

AMU 28 (N 2 ) Process is complete. FDC sends the command to ignite the RGA filament.

RGA contaminated bottle controlled test

• A small Ar bottle that was purposely contaminated with 1600ppm of N2 was connected to a PVD chamber as a controlled test.

1,40E-05 1,20E-05 1,00E-05 8,00E-06 6,00E-06 4,00E-06 2,00E-06 0,00E+00 Ar36 Test Bottle N2 Test Bottle Ar36 House Bottle N2 House Bottle N2 Contamination 1 11 21 31 41 51 61 71 Time * The Ar36 isotope was chosen for the graph instead of Ar40 because of the signal magnitude relative to the magnitude of N 2 . Sample © 2013 TriQuint Semiconductor, Inc.

Example 1: Real Time RGA Alarm

•Ar should be present.

•O 2 and H 2 are baseline signals.

•N 2 peak (pulse) detected.

Example 2: Chamber Lid Leak RGA Trace

AMU28 (N2)-

Red



Blue



Chamber lid leak Normal

Future Work

• Implementing RGA at house Ar gas supply – Detect problem at time close to

t 0

Conclusion

• There is great value in integrating RGAs and other sensors into an in-house FDC system.

Acknowledgement

• The authors want to express their appreciations for the valuable inputs on this project from Romek Bobkowski and Richard Groom, both of TriQuint Semiconductor Corporation on PVD processing and RGA operation respectively.