Mahdi,

The following methods work best on whole or larger wafers sections

If the wafer sections have an etched side, a good and easy non destruct
methods to determine orientation is to use a small blue, green or red
LED light ( I use both keychain light as well as some of the lighted
writing pens)
with the product in a semi dark location ( even under a desk will work
often) shine the light on the section and look for the orientation
pattern. 1-0-0 will have 4 ( primary) point cross pattern at 90 degrees.
1-1-1 will have 3 Primary) point cross pattern at 120 degrees of
seperation.
The 1-0-0 may also have an additional 4 point secdondary lines at 45
degree from the primary and the 1-1-1 may have multiples of 3 lines.

If the LED doesnt work ( sometimes if the surface is too relective
another way is to use a laser pointer ( or any laser) with a white round
shroud ( a filter paper would do) with a hole in the center and place
the section in front of the laser and then look at the reflected pattern
on the front side of the Shroud. This works well for higher reflective
wafers, but not polished ones.

If you know all the sections are from one orientation and the above does
not work, then take a section and use a sharp point to tap to break the
section and see how what the break pattern is.

There are other methods but not as easy in a normal lab.

Might try these first.

Regards.
Ken Smith
Kmbh Associates
47 Rocket Circle
Rancho Cordova, CA 95742  U  S  A
510-714-5055 Efax- 510 217 4421
High Purity Float Zone and Specialty CZ Silicon


mahdi bagheri wrote:
> Hello everybody
> We have some fragments of Si wafer, but we don`t know the orientation of those
because they don't have any flat edges. Is there any method to recognize the
orientation of the Si wafer?
> Regards
> Mahdi