Fast Vacuum for Optical Disc Metallization
and Photovoltaic Coatings
B. Cord, M. Hoffmann, O. Hohn, F. Martin
SINGULUS Technologies AG, Kahl am Main
SINGULUS
TECHNOLOGIES
June 2014
SINGULUS TECHNOLOGIES AG
25-June-2014 - 2 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
SINGULUS Overview
Replication CD, DVD, Blu-ray Vacuum (UHV) Multi-Layer Deposition Vacuum coating,
Thermal Treatment,
Chemistry
SINGULUS TECHNOLOGIES AG
25-June-2014 - 3 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Content
Optical Disc: Dynamic Vacuum at Metallization
Pirani-, Diaphragm-, Ion-Gauges
Photovoltaics: Process Pressure Measurement for
Plasma Enhanced Chemical Vapour Deposition
(PE-CVD)
Capacitance (Diaphragm) Gauges
SINGULUS TECHNOLOGIES AG
25-June-2014 - 4 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
BD-Dual Layer (50GB)
PC-Disc: 1.1 mm
Reflector L0: 35 nm Ag (<60%R<85%)
Laquer: 72 μm
Moisture Barrier: 10 nm SiN
Laquer Hardcoat: 3 µm
Laquer: 25 μm
Semi Reflector L1: 25 nm Ag (<18%R<30%)
Optical Disc Blu-ray ROM
Fully Automated Production: CD, DVD and Blu-ray
Vacuum
(Sputtering)
SINGULUS TECHNOLOGIES AG
25-June-2014 - 5 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Single Station Magnetron Sputtering System
Cycletime 1,5 - 4,5s
CD-Metallizer SINGULUS
Sputter Station:
- Gassupply Ar
- Turbomolecularpump
- Ion gauge
(10-4 to 1 Pa)
Small volume Loadlock:
- Volume about 100ccm
- Prepump of about 20cbm/h
- Piranitype vacuumsensor
(1 to 10+5 Pa)
DVD-System Spaceline BD-System BLULINE
Turntable:
- Rotation 180° and
- Up and down
SINGULUS TECHNOLOGIES AG
25-June-2014 - 6 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
BLULINE: Vacuum Layout
Process chamber vacuum:
(turbomolecular pump,
ion gauge)
10-8Pa base pressure
Loadlock:
(prepump, Pirani Gauge in
pump line):
Setting of pumpdown
threshold (in mV of gauge
reading)
Display of evacuation time
(ms)
500ms = 1mbar (= 6200mV) Prepump
Loadlock
Venting
Loadlock
Pumping
Process
Chamber
Vacuum Schematics: Loadlock and process chamber
SINGULUS TECHNOLOGIES AG
25-June-2014 - 7 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Metallizer: Dynamic Vacuum in Load lock
Opening of pump valve Closing of pump valve
Threshold
vacuum trigger:
45 Pa
Load lock: Pump down
Base pressure pump
SINGULUS TECHNOLOGIES AG
25-June-2014 - 8 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Metallizer: Dynamic Vacuum in Load lock
Opening of pump valve Closing of pump valve
Threshold
vacuum trigger:
45, 100, 200, 500 Pa
Load lock: Pump down
SINGULUS TECHNOLOGIES AG
25-June-2014 - 9 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Metallizer: Dynamic Vacuum in Loadlock
Process chamber:
Bayard Alpert Gauge
Load lock:
Pirani Gauge
Start pump down
Load lock
Closing of pump valve and
opening of load lock
to process chamber
Loadlock: Pumpdown; Pressure burst into Process chamber
Pressure
burst Closing of load lock
to process chamber
2s
SINGULUS TECHNOLOGIES AG
25-June-2014 - 10 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Metallizer: Dynamic Vacuum in Process Chamber
Opening of load lock
to process chamber
(different thresholds)
Process chamber:
(one TMP)
Process chamber:
(two TMP’s)
SINGULUS TECHNOLOGIES AG
25-June-2014 - 11 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Metallizer: Dynamic Vacuum in
Process Chamber with Argon gas
Gauges:
Pirani Bayard Alpert Ion Gauge
Argon gas
Air from
load lock
Plurality of gauges
at DN25 cross
Dynamic behaviour of different gauges
SINGULUS TECHNOLOGIES AG
25-June-2014 - 12 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
BLULINE: Dynamic Vacuum in Load lock
Pirani Gauge in pumpline
Additional Pirani gauge at loadlock
(for experiment only) Loadlock vented
Start pump down
Late reaction of Pirani
after start pumpdown
Pirani: Dynamic behaviour at high Pressures (>1000Pa)
Base pressure pump
SINGULUS TECHNOLOGIES AG
25-June-2014 - 13 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Loadlock: Dynamic Vacuum Measurement
Start pump down
(opening of valve)
Pirani /Diaphragm gauge
bottom of load lock
Pirani/Diaphragm
gauge top of load lock
Pirani
gauge top of
load lock
Late reaction of
Pirani after start
pump down
Pirani: Study of Dynamic behaviour at high Pressures (>1000Pa);
Comparison to combined Pirani/Diaphragm
SINGULUS TECHNOLOGIES AG
25-June-2014 - 14 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Loadlock: Dynamic Vacuum Measurement
Slow venting
Fast venting
Pirani: Study of Dynamic behaviour at high Pressures (>1000Pa);
Comparison to combined Pirani/Diaphragm
Pirani
Pirani
Combined
Pirani/Diaphragm
Combined
Pirani/Diaphragm
SINGULUS TECHNOLOGIES AG
25-June-2014 - 15 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Optical Discs: Pirani – Diaphragm – Ion
Gauges
Summary of Gauges for rough and high vacuum
Pirani: Gauge of choice for 100Pa level with good time resolution
Pirani shows large deviations for dynamic vacuum measurement
at levels of >1000Pa
Combined Pirani/Diaphragm gauge good solution up to 1000hPa
Ion gauges seem to be fastest
Absolute, precise pressure measurement with ion gauges
needs careful integration and calibration
SINGULUS TECHNOLOGIES AG
25-June-2014 - 16 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Photovoltaics: Coating of Si-wafer with Si-Nitride
→ SINGULAR multi chamber coating tool
→ Inductively coupled plasma source
→ Deposition by Plasma assisted
chemical vapor deposition (PECVD)
→ Process gases like NH3, SiH4, N2, ….
→ Modular design for various processes
(e.g. SiNx, AlOx, a-Si)
Four identical PECVD
Process stations
SINGULUS TECHNOLOGIES AG
25-June-2014 - 17 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
TECHNOLOGY: ICP - PECVD
Process pressure
Measurement:
Direct Pressure gauges
(Diaphragm, Capacitance)
Pressure Measurement of Process gases for PECVD:
• Usage of gas independent sensors (Diaphragm Capacitance Gauges)
• Range 0,01 to 100 Pa
• Avoid decomposition of gases at hot filaments (no ion gauges)
• Issue of sensor contaminations
Plasma chamber Substrate
Pump
SINGULUS TECHNOLOGIES AG
25-June-2014 - 18 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
TECHNOLOGY: ICP - PECVD
SiH4 NH3
Additional Gas
Valves
Plasma: Inductively coupled plasma (ICP)
Vacuum: 0,01 to 100 Pa
Static SiNx Process:
Process on 9s, transport 3s with no gas
going into chamber (avoid chamber
crosscontamination)
Flowcontroller
Gas Valves
SINGULUS TECHNOLOGIES AG
25-June-2014 - 19 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Photovoltaics: PECVD Stations
with Capacitance Gauges
Different
SiH4 Flows
Topic: Actual pressure in chamber after gasflow switching
Pressures SiH4
Pressures NH3
Flows NH3
Flowmeter on
Valve opening
SINGULAR:
Pressures in Chamber without plasma
Flowmeter on
SINGULUS TECHNOLOGIES AG
25-June-2014 - 20 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Photovoltaics: PECVD Stations
with Capacitance Gauges
SINGULAR Machine#1:
Pressure versus Flow relation:
- Measurement at four stations
- Machine to machine comparison
SiH4
NH3
Topic: Station to station comparison of process pressure
at identical gas flows
SINGULUS TECHNOLOGIES AG
25-June-2014 - 21 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Photovoltaics: PECVD Stations
with Capacitance Gauges
SINGULAR Machine#2:
Pressure versus Flow relation:
Measurement at four stations
SiH4
NH3
Pressure Deviation
at Station 4 (No#2)
Topic: Station to station comparison of process pressure
at identical gas flows
SINGULUS TECHNOLOGIES AG
25-June-2014 - 22 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Photovoltaics: PECVD Stations
with Capacitance Gauges
SINGULAR Machine #1 and #2:
Comparison SiH4
NH3
Precise and stable pressure
measurement over time and
from sensor to sensor required
Topic: Machine to machine comparison of process pressure
at identical gas flows
SINGULUS TECHNOLOGIES AG
25-June-2014 - 23 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Photovoltaics: PECVD Stations
with Capacitance Gauges
SINGULAR
Pressures in Chamber without plasma
Different gas
valve
opening times
Topic: Actual pressure in chamber after gasflow switching
Optimizing the gas inlet
for shortest pressure
stabilization time
SINGULUS TECHNOLOGIES AG
25-June-2014 - 24 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Photovoltaics: PECVD Stations
with Capacitance Gauges
Summary Capacitance Gauges for PECVD
Accuracy of absolute pressure measurement good (but not perfect)
Often zeroing of gauge required
Signal rise/fall times in the range of some hundred milliseconds,
but difficult to judge due to gas filling times for the vacuum
chamber
SINGULUS TECHNOLOGIES AG
25-June-2014 - 25 -
PTB, Workshop on Vacuum Metrology, June 25th 2014
Question:
Operation of the Capacitance Gauges:
Absolute pressure accuracy over time?
What is best routine for the often required zeroing?
Thanks for your attention
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