Chemical impurities in units of ppm (parts per million).
Absence of numbers indicates that, either the element is not present or no measurement was taken at the time.
Elements
PT
ID
Fused Quartz
Fused Silica
Electric Fused
Flame Fused
Standard
Semi Dry
Dry
Very Dry
Hydroxil
OH
5.000
1800
1,200.000
700.000
100.000
10.000
Aluminum
Al
10.000
9.000
0.100
0.020
0.001
0.001
Antimony
Sb
0.003
-
0.004
-
-
-
Arsenic
As
0.002
-
-
-
-
-
Barium
Ba
-
-
-
-
-
-
Bismuth
Bi
-
-
-
0.040
-
-
Berilium
Be
-
-
-
0.030
-
-
Bromine
Br
-
-
-
0.002
-
-
Boron
B
0.200
-
-
1.000
-
-
Cadmium
Cd
0.010
-
-
0.080
-
-
Calcium
Ca
0.400
0.600
0.100
-
> 0.001
> 0.001
Chlorine
Cl
-
-
-
-
-
-
Chromium
Cr
0.050
-
-
0.006
> 0.001
> 0.001
Cobalt
Co
-
-
-
0.001
> 0.001
> 0.001
Copper
Cu
0.050
0.030
0.010
-
> 0.001
> 0.001
Gallium
Ga
-
-
-
0.020
-
-
Germanium
Ge
-
-
-
0.060
-
-
Gold
Au
-
-
-
0.001
-
-
Hafnium
Hf
-
-
-
-
-
-
Iron
Fe
0.200
0.400
0.050
0.200
> 0.001
> 0.001
Lithium
Li
0.600
0.200
0.050
0.210
> 0.001
> 0.001
Magnesium
Mg
0.100
-
-
-
> 0.001
> 0.001
Manganese
Mn
0.050
-
-
-
-
-
Molybdenum
Mo
-
-
-
-
-
-
Nickel
Ni
0.100
-
-
-
> 0.001
> 0.001
Phosphorus
P
0.200
-
-
-
-
-
Potassium
K
0.060
0.200
0.050
-
> 0.001
> 0.001
Silver
Ag
-
-
-
-
-
-
Sodium
Na
0.700
0.600
0.050
0.023
> 0.001
> 0.001
Strontium
Sr
-
-
-
-
-
-
Thallium
Tl
-
-
-
0.050
-
-
Titanium
Ti
1.100
-
-
-
> 0.001
> 0.001
Uranium
U
-
-
-
-
-
-
Zirconium
Zr
0.800
-
-
-
-
-
Zinc
Zn
-
-
-
-
> 0.001
> 0.001
Note : Hydroxil species in the material art exhibiting high IR absorption which
provides a reliable base to calculate the OH content of the wafer.
Permeability
Quartz and Silica are impermeable for most gases. Although, Hydrogen, Deuterium and Helium does diffuse through at elevated temperatures under special processes and conditions.
The permeability constant is estimated to be approximately;
@600oC /cc/sec./cm2/mm/cm.Hg
Helium =
2.192 x 10-8
Deuterium =
1.812 x 10-9
Hydrogen =
2.110 x 10-9
Chemical Durability.
Quartz and Silica has exceptional durability properties against most chemicals. Exposure to chemicals will not cause visible surface change or damage.
There are two exceptions.
HF (40% solution), etching rate:
=13,000 Angstrom / min.
NaOH (30% solution), etching rate:
=5.8 Angstrom / min.
All others, etching rate:
= />1.0 Angstrom/min.
Reactivity of Quartz and Silica Toward Other Materials.