5 – 24
Transpector SPS Operating Manual
5.3.1.6 Tungsten CVD
lists some of the materials of interest and the masses at which to monitor
them for blanket tungsten or tungsten silicide deposition. Oxygen and water vapor
are unwanted contaminants during tungsten deposition because they react with the
tungsten hexafluoride to produce tungsten oxyfluorides and oxides, which, except
for WOF
4
, are nonvolatile and can result in particle generation. The presence of
WOF
4
may be the only indication that water vapor or oxygen are also present, but
not detected by the mass spectrometer because of rapid reaction with the tungsten
hexafluoride.
Si
3
N
4
CF
4
/O
2
CF
4
O
2
SiF
4
NF
3
CO
2
HF
H
2
O
COF
2
N
2
CO
69, 50, 31
32, 16
85, 66, 47
52, 33, 71
44
20
18, 17
47, 66
28, 14
28, 12
Poly-Si
BCl
3
/Cl
2
HBr/Cl
2
/O
2
BCl
3
Cl
2
SiCl
4
HCl
H
2
O
HBr
Cl
2
O
2
SiCl
4
SiBr
4
SiBr
X
Cl
(1-X)
H
2
O
HCl
81, 83, 116, 118, 46, 48
70, 72, 74
133, 135, 170
36, 38
18, 17
80, 82
70, 72, 74
32, 16
170, 133, 135
348, 267, 269
many peaks
18, 17
36, 38
Table 5-5 Dry etching chemistries (continued)
Etched
Material
Typical
Reagents
Important
Species
Monitored
Masses
