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Dear all,
Thanks for those people who send me e-mails and share their experience on =
break wafers. Yes, it is a little trick skill. I would like to put all in =
this e-mail and share with you. it's simple but still need some more =
practice. Hope it can help.
Best regards,
Jun
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I always use a ruler and use the diamond pen on the back side of the =
wafer. Then I use both hand and break it along the line I created with =
the pen or sometimes I use a glass slide on one side to help keep it =
straight.
-Angela Rasmussen
The George Washington University
The Institute of MEMS and VLSI Technologies
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hi jun,
=09
i have to say it's going to be hard to tell someone how to cleave over =
email, but it's interesting enough..
so, [111] is hard because only one of the cleaving line runs perpendicular =
to the flat, the other two runs 60 degrees off that, so it really wnats to =
curve, nothing you can really do except being careful and take the =
following advice.
for [100], it will be simple with practice. the most useful trick i found =
is when you draw the line to help it cleave, do the following:
1) use a glass slide and make it perpendicular to one of the =
cleaving planes (say, the major flat)
2) draw the initial line (3-4 mm long) starting from center of =
wafer to teh edge direction, softly first and then press down hard as you =
go over the edge of teh wafer
3) put one glass slide underneath the wafer and one on top, both =
aligned parallel and on the edge to the cleave line you've drawn.
4) press hard on the glass slide with one hand, and softly tap the =
wafer with your diamond pen.
this should initiate a cleave running along the line you've drawn. if you =
have to press hard on teh wafer with your diamond pen, it is not working. =
redraw on the same line..
well, good luck.. it comes with experience, don't get frustrated :)..
jia
cornell university
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Hi Jun,
A trick I use which has work rather well for me is to place a glass slide =
over the wafer and use the diamond scribe to draw a line along the slide. =
Then, place the slide under the wafer along the line you have just drawn =
and tap the wafer with the back of the diamond scribe. The wafer will =
break along the line, or rather along the edge of the slide under the =
wafer.
Good luck.
Chen=20
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Dear Zhang,
If you are making your design by yourself then there is very nice trick. =
Just where you want to break you wafer make some holes on certain =
distance. The mask openings of the hole should be about 600microns for =
approx. 500microns thick wafer. Then you can break it whenever you want =
even by hand.
Regards,
Vladimir
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Jun,
You can use your diamond scriber to lightly scribe along the straight line =
where you want the wafer to break. Use a ruler and scribe only once. Then =
support the wafer on another straight edge, such as a ruler, right below =
the scribed line. Press the wafer steadily and use the other end of the =
scriber to gently tap on various parts of the free end of the wafer. I =
could get that to work on up to 4-inch 500 um thick wafer. Using another =
straight edge on top of the scribed line helps further.
Another practice is to use a scriber and another metal tool to press on =
the two ends of a wafer on top of a compliant surface, such as several =
layers of cleanroom wipes. The wafer usually cracks in a straight line =
between those two pressure points.
Have fun breaking wafers.
Patrick Cheung, research scientist Xerox PARC, MS 35-1674
(O) 650-812-4338 (FAX) 650-812-4719 3333 Coyote Hill Road
[email protected] Palo Alto, CA 94304 =
"pcheung can mems, and so can you!"
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111 material has triangular crystal structure. You have to scribe up =
through the base of the triangle, as opposed to the vertex of the =
triangle, so orientation is important. Usually, this is delineated by a =
flat along the 110 plane. Scribe heavily, but only one time if possible. =
100 should be much easier to scribe just be careful that your scribe line =
is parallel to the planes.
My technique uses a 1x2 inch glass slide placed on top of the wafer. This =
is used as the straight edge for scribing. Once scribed rest the wafer on =
another slide with the scribe line just overhanging the lower slide. Then =
sandwich the wafer with another slide. Apply pressure on the outermost =
edge of the wafer and increase the pressure until the wafer breaks. Good =
luck it is an art.
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Hi Jun,
To break the silicon, I first lay the wafer on a cleanroom cloth (to have =
something soft under the wafer). Then, on one side of the wafer I push =
with a sharp tweezer while slightly scratching on the other side with a =
diamond pen.To have a straight breaking line, it is important that the =
strain is applied along the crystaline plane of the silicon. That is, the =
line between you tweezer and diamond pen have to be parallel or perpendicul=
ar to the flat for (100) silicon wafers. I hope with can help.
Good luck
Gregoire
Gregoire Genolet
