Veeco Mark II - Page 75

71
Total Output Ion Beam Current, Low Voltage Option
FIGURE B.11 and ”FIGURE B.12” on
page 72 show total output ion
beam currents
for the for the Mark II source’s low voltage option in a
normal range of operation of interest for most applications in argon and
oxygen. This source option’s total current of accelerated ions is about 15
to 25% of the anode-to-cathode current used to sustain the ion source
discharge. Note that the source’s low voltage option runs at lower input
gas levels; as a result, this source option produces a lower overall beam
current for the same input power settings.
FIGURE B.10 Angular Beam
Current Density at R=30cm
and Anode Current= 7.5A -
Low Voltage Option (Oxygen).
Angular Ion Beam Current Density Profile at R=30 cm
(Oxygen with Anode Current of 7.5A)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90
Angle (degrees)
Beam Current Density (mA/cm
2
)
75V
100V
150V
200V
FIGURE B.11 Total Ion Beam
Current vs. Anode Voltage at
R=30cm.- Low Voltage Option
(Argon).
Total Beam Current for Argon at R=30 cm
0
0.5
1
1.5
2
2.5
0 50 100 150 200 250
Anode Potential (V)
Total Integrated Beam Current (A)
1A
3A
5A
7.5A
10A
15A