Brooks Instrument XacTorr CMX160 - Manual (Page 15)

p.9
Table 2: CMX Model Application
2.8 PRESSURE RANGE SELECTION CRITERIA
When selecting a capacitance manometer, the measurement range of the
instrument should be considered especially if the CMX is part of a closed loop
pressure control system. In general, CMX measures over 4 decades (from their
full scale range) and can be used in closed loop pressure control systems over a
maximum of 3 decades.
Figure 8: Measurement and Control Ranges of CMX
MODEL
APPLICATION PROCESS CMX45 CMX100 CMX160
Metal NR R OK
Oxide R OK OK
Etch Silicon/
Polysilicon
R OK OK
Dielectric OK R NR
Photoresist R OK OK
Metal NR OK R
Oxide OK R OK
CVD Silicon/Poly-
silicon
OK R OK
Dielectric NR OK R
PVD R OK NR
R = RECOMMEND OK = ACCEPTABLE NR = NOT
RECOM-
MENDED
Measurement Range = 4 decades
Control Range = 3 decades
Control Range Measurement Range
Full-Scale
Device
Range
(T
orr)
1000
100
10
2
1
0.1
1000
100
10
2
1
0.1
Process Pressure (Torr)
10 10 10 10 10 1 10 100 1000 -5 -4 -3 -2 -1
2.0
_DESCRIPTION