Oxford-100-Manual.pdf - 第110页

PiasmaiabSystem100 Process gas pod mimic Oxford Instruments Plasma Technology Displays a mimic of the gas lines installed in the gas pod. System Manual Enter the required gas flow in sccm for each gas line. Click on the …

100%1 / 362
System
Manual
Oxford
Instruments
Plasma
Technology
PlasmalabSystem
100
LOW
PRESSURE
STRIKE panel
The
low
pressure strike
feature
allows plasma processing
at
low
pressures.
When
the
gas pressure
is
too
low,
it
is
not
possible
to
strike
a plasma;
however
it
is
possible
to
sustain a plasma
to
very
low
pressures once
it
has been
ignited.
This
software
feature
enables
the
user
to
raise
the
pressure
temporarily,
strike a plasma, and
automatically
reduce
the
pressure
to
the
desired
value
for
processing.
The
three
data fields and
their
effects are:
Strike
Pressure
field
DC bias
Minimum
field
Ramp
Rate
field
Enter
the
value in
mTorr
at
which
the
RF
should
turn
on and strike
the
plasma.
If
a zero
is
entered,
the
feature
is
disabled and
the
RF
will
turn
on once
the
pressure has stabilised
at
the
requested process
pressure.
Enter a positive
number
for
the
minimum
DC
bias
value expected once
the
plasma has struck. Enter
zero
if
DC
bias
cannot
be read because
the
substrate (and any
wafer
clamp)
completely
cover
the
electrode,
or
if
the
electrode has an insulating
coating. A
non-zero
value
is
used by
the
software
to
detect
if
the
plasma has been
properly
established.
If
a
zero
is
entered,
then
the
software
assumes
the
plasma has struck once
the
RF
reflected
power
goes
low.
Enter a
number
to
set
the
rate
at
which
the
pressure
is
reduced
from
the
strike
value
to
the
set
point.
The
higher
the
number
entered,
the
faster
the
transition
to
process conditions
will
be.
Note
that
too
high
a value can cause
the
plasma
to
go
out
if
the
plasma impedance changes faster
than
the
RF
matching
unit
can track.
Printed: 22-Mar-06, 10:42
Operating
Instructions
Page 5-43
of
52
UC
Davis 94-721001
Issue
1:
March 06
PiasmaiabSystem100
Process gas
pod
mimic
Oxford
Instruments
Plasma
Technology
Displays a
mimic
of
the
gas lines installed
in
the
gas pod.
System
Manual
Enter
the
required
gas
flow
in
sccm
for
each gas line. Click
on
the
Gas
Name in an MFC
mimic
to
edit
the
associated
Gas
Factors;
the
following
dialogue
is
displayed.
Gas Factor Editor •
It
is
recommended
to
keep
the
Gas Factor
as
1,
and
to
put
the
full
scale
of
the
MFC
for
the
gas used in
the
Mass
Flow
field.
For example,
if
Argon
is
used
with
a 100
seem
N
2
MFC.
Put
gas
factor
1
and Mass
Flow
141
seem.
UC
Davis 94-721001 Issue
1:
March
06
Operating
Instructions
Page 5-44
of
52
Printed: 22-Mar-06. 10:42
System
Manual
Oxford
Instruments
Plasma
Technology
PlasmalabSystem
100
5.8.6
Leak
detection
page
Fig 5.17:
Leak
detection page
The leak
detection
page, accessed
from
the
Chamber 1 process page
by
selecting
the
Leak
Detection
button,
allows
you
to
perform
automatic
or
manual leak
detection
runs.
The Leak Detection page
for
a process chamber can be used
to
check
the
rate-of-pressure rise
in
a sealed chamber. The chamber
is
first
pumped
(either
for
a
fixed
time,
or
to
a given
pressure). The chamber
then
seals and
the
pressure rise
rate
is
calculated. A
graph
of
the
chamber pressure against
time
is
plotted.
The test stops
either
when
a
test
time
elapses.
or
when
the
pressure
gauge
reaches
full
scale. The chamber
is
returned
to
pumping
at
the
end
of
the
test.
The rate-of-pressure rise
will
depend
on:
a)
The leak rate
from
atmosphere. Leaks are
not
improved
by
more
pumping.
b) The outgassing rate
from
all surfaces.
c)
The
'virtual
leak'
rate
from
parts
of
the
system
furthest
from
the
vacuum pump.
especially gas feed pipes.
Outgassing and
virtual
leaks are reduced
by
more
pumping.
Outgassing
is
increased
if
the
temperature
of
the
whole
system
is
raised.
The facilities available
on
this page are:
Page
function
Displays
the
current
function
of
the
page,
Le.
Leak Detection
title
field
Process
chamber Displays
context
related messages
about
the
process chamber.
message
field
Printed: 22-Mar-06, 10:42
Operating
Instructions
Page 5-45
of
52
UC
Davis 94-721001
Issue
1:
March 06