Oxford-100-Manual.pdf - 第280页
All OIPT Systems Oxford Instruments Plasma Technology System Manual Auto/manual switch: In the 'Auto' position, the unit will attempt to tune for minimum reflected RF power. In the 'Manual' position, …
System
Manual
Oxford
Instruments
Plasma Technology
All OIPT Systems
(corresponding
to
RV101)
to
position
'a'
and begin
turning
the
potentiometers
anti-
clockwise again
until
the
oscillations stop.
15)
Confirm
the
automatching
behaviour, increasing
the
RF
power
to
maximum in small
steps,
repeating
Steps 10
to
13
if
necessary.
4.
Operator
adjustment
WARNING
THE FOLLOWING ADJUSTMENT INVOLVES WORKING ON
THE
SYSTEM WITH
PANELS/COVERS REMOVED. IT SHOULD ONLY
BE
CARRIED OUT BY TRAINED
PERSONNEL
WHO
ARE AWARE
OF
THE
HAZARDS INVOLVED.
4.1
DC
bias I
Peak-to-peak
switch
setting
The DC bias /
Peak-to-peak
switch
is
located
on
the
outer
case
of
the
AMU,
adjacent
to
RV1
(null
adjustment
potentiometer).
See
Fig
1,
page
3.
This switch selects one
of
two
sensing
output
signals
from
the
AMU:
DC bias: This switch
setting
is
the
default
position. The
output
is
a
SCALED
dc
voltage
proportional
to
the
RF-induced self-bias on
the
electrode,
sometimes called
the
'DC
bias'. This
is
a negative
offset
voltage
on
the
electrode
with
respect
to
ground,
which
is
inverted and conventionally
referred
to
as
a positive value, typically 100 - 600 Vdc. Normal scaling can
read
up
to
1000 Vdc. This signal
is
read by
the
front-end
software
with
correct scaling
on
OIPT
tools.
Peak-to-peak:
The
output
is
an UNSCAlED dc
voltage
related
to
the
peak-to-peak value
of
the
RF
signal
at
the
output
of
the
automatch.
This can be useful
when
the
scaled dc bias
is
inaccessible,
for
example
if
the
electrode has
no
dc
contact
to
the
plasma because a
quartz
carrier
plate
masks
the
whole
electrode. The value displayed on
the
PC
screen
will
be an
arbitrary
value,
not
a
true
peak-to-peak value,
but
can still
be
a useful
monitor.
Note
that
the
software
has
no
knowledge
of
the
switch
setting
and
is
scaled
only
for
the
dc
bias setting.
5.
Operation
If
the
automatch
has been set
to
'auto',
the
unit
will
attempt
to
reduce
the
reflected
RF
power
to
minimum
without
the
need
for
operator
adjustments.
It
will
normally
reduce
reflected
power
to
less
than
2%
of
forward
power.
Use
manual
matching
for
the
following:
a)
One
or
both
capacitors has driven
to
a
limit.
b) To discover
if
a match exists
within
the
range
of
the
matching
unit.
The
adjustment
panel
for
the
automatch
is
located
behind
a
hinged
cover. Opening
the
cover
reveals
the
following
controls and indicators:
Printed: 5-Jan-06. 8:03
OIPT
Automatch
Unit
Page 13
of
20
Issue
6:
February 05
All
OIPT Systems
Oxford
Instruments
Plasma
Technology
System
Manual
Auto/manual
switch: In
the
'Auto'
position,
the
unit
will
attempt
to
tune
for
minimum
reflected
RF
power. In
the
'Manual'
position,
the
capacitors
positions are
controlled
manually.
C1
max/min switch: In manual mode, this switch can be used
to
drive
capacitor
C1
towards
maximum
or
minimum.
C2
max/min switch: In manual mode, this switch can be used
to
drive
capacitor
C2
towards
maximum
or
minimum.
Note
that
capacitor positions are displayed
as
a
three-digit
number
from
000 (minimum)
to
999 (maximum).
Display Selector
Switch:
C1
park.
Potentiometer:
C2
park.
Potentiometer:
The
RF
monitoring
positions display
the
analogue
voltages
on
the
remote
control
lines
to
the
RF
generators,
as
a service aid. The
Hillo
position reads a
high
(>9V) value
when
the
wafer
bias
RF
supply
is
at
full
scale, and a
low
«1V)
value
when
this supply
is
scaled back
to
one-
tenth
full
power. This
feature
improves resolution
of
RF
low
power.
This
control
can be
fitted
either
to
the
control
panel
or
on
the
AMU
control
board. The
automatch
will
drive
C1
to
this pre-set position
when
the
RF
is
turned
off,
if
the
unit
is
set
to
'auto'
This
control
can be
fitted
either
to
the
control
panel
or
on
the
AMU
control
board. The
automatch
will
drive
C2
to
this pre-set
position
when
the
RF
is
turned
off,
if
the
unit
is
set
to
'auto'
Issue
6:
February
05
DIPT
Automatch
Unit
Page 14
of
20
Printed: 5-Jan-06. 8:03
System
Manual
Oxford
Instruments
Plasma Technology
All OIPT Systems
6.
Troubleshooting
WARNING
HAZARDOUS
RF
VOLTAGE - CONTACT CAN CAUSE DEATH,
SEVERE
INJURY
OR
BURNS.
ANY
WORK REQUIRING
THE
REMOVAL
OF
COVERS
OR
PANELS MUST
ONLY
BE
PERFORMED
BY
AUTHORISED PERSONNEL WHO
ARE
AWARE
OF
THE
HAZARDS INVOLVED.
6.1
Fault
diagnosis
chart
Use
the
following
chart
to
locate
and
identify
faults.
Note
that
the
chart
lists typical
fault
symptoms
and
is
not
exhaustive.
SYMPTOM
POSSIBLE CAUSES ACTION
(A)
Drive
motors
do
Fuse
FS2
blown
Investigate
and
repair
fault,
which
caused
the
not
respond
to
fuse
to
blow.
Then
renew
the
fuse.
automatic
or
manual
control
Fuse
FS1
or
FS101
tripped.
Investigate
and
repair
the
fault,
which
caused
the
fuse
to
trip.
(The fuses
will
automatically
reset once
the
fault
is
repaired.)
Note
that
these
components
are
semiconductor
fuses
which
respond
to
an increase in
current
above
their
rating
(approximately
200 mA)
by
increasing
their
internal
resistance significantly.
The
voltage
drop
across each
of
these
components
under
non-fault
conditions
is
approximately
0.5V
When
tripped
by
high
current,
the
voltage
drop
is
almost
the
full
supply
voltage
i.e. 24V.
After
power
is
removed,
the
devices
require
20
seconds
to
cool
down
and
reset.
(8)
C1
or
C2
drive
to
1.
C1
or
C2
starting
too
far
Adjust
park
potentiometers
(Refer
to
sub-
min
or
max
from
final
match
position
section 6.4 (paqe 20).
2.
Match
position
is
out
of
1.
Change process
conditions
accessible
range
2.
Change
component
fit
in
AMU
(skilled
personnel only). Refer
to
sub-section 6.3 (page
19).
(C)
C1
or
C2
drive
to
Capacitor
has
travelled
past
1.
All
vane capacitors
only:
Continue
manual
min
or
max
and
do
an electrical
limit
travel
in
the
same
direction
(to
max
if
capacitor
not
return
is
at
max). The
capacitor
will
turn
fully
until
it
manually
passes
the
opposite
limit.
2.
Readiust
limit
settinqs
(D)
Plasma does
not
Gas
pressure
is
too
low
or
Caution:
do
not
run
for>
2
minutes
in
this
strike
even
though
too
high
condition.
Change gas pressure
to
20 - 200
the
reflected
power
mTorr
range
(RIE),
or
0.5
-1.5
Torr
range
is
low
(PECVD)
Printed: 5-Jan-06. 8:03
DIPT
Automatch
Unit
Page 15
of
20
Issue
6:
February 05