Polished Optical Grade Silicon

Although Silicon
is primarily grown for semiconductor applications, it is the most economical
IR material available. For optical use, Silicon is produced by the CZ crystal
growth method or by the Float Zone growth method. Both P-type and N-type are
acceptable for IR optics provided that they offer transmission greater than
50% in the 1.5 to 6 micron wavelength. Generally speaking, for N-type, the resistivity
should be greater than 20 ohm-cm and, for P-type, greater than 40 ohm-cm. For
use in the near IR, this is not so critical, but for applications for the far
IR, resistivity can be critical. Float Zone Silicon most always meets criteria
for optical use.

Available sizes
in <1·1·1> and <1·0·0> orientation, N and
P-type include 1″, 2″, 3″, 100mm, 125mm, 150mm, 200mm and 300mm diameters and can also be custom sized or diced. With a readily available Silicon source, matched with our extensive shaping and
polishing capabilities, Valley Design will assuredly meet your optical grade
Silicon needs on short notice.

When requesting a
quote or just to check our inventory, please include complete information: Quantity,
Wafer diameter, Thickness, Type, Orientation <1·1·1> or
<1·0·0>,
Resistivity range, TTV (if important), Polishing, Edge condition (if applicable),
Orientation flat specification, if other than SEMI standard.

Valley Design stocks N-type, P-type
and Float Zone Silicon, but recommends that customers with optical applications
check a small sample for transmission before making a larger purchase. Other
polished infrared materials available from Valley Design are Germanium (Ge),
Zinc Selenide (ZnSe) and Zinc Sulfide (ZnS).