Miller indices Wafer Geometry Wafer is 0.5 mm thick and 100 to 150 mm (4 to 6 inch) in dia. Good die are completely inside the margin region Miller indices Miller indices (watch the video: http://www.youtube.com/watch?v=9us_oENGoM) 1. Set the coordinate axes along the edges of the unit cell 2. Let the plane to be indexed intercept the axes 3. Divide it by unit cell length 4. Record these pure number set in the order x,y,z 5. Invert these values (from 1,2,3 to 1, ½, 1/3 6. Find out LCM of the denominator and multiply each with this (6x1, 6x½, 6x1/3 = 6,3,2) 7. Enclose the whole-number set in small brackette (6,3,2) Note: 1. If the plane to be indexed is parallel to a coordinate axis, the intercept is infinity and hence the index would be 0 2. If the plane to be indexed is in the –ve portion of a coordinate axis, a minus sign is placed over the corresponding index number 3. A group of equivalent planes is concisely referenced through the use of {}, such as {100} 4. Direction of the plane is referenced through the use of [], such as [100] Note: Six planes, (100), (010), (001),(100), (010) and (001) are identical planes and hence are represented by {100} (100), (110) and (111) represent three different planes. Can you reflect on planes, (100), (200), (300) – if these are identical planes? Miller notation summary Convention Interpretation (hkl) Crystal plane {hkl} Equivalent planes [hkl] Crystal direction <hkl> Equivalent directions The [100] direction is normal to the (100) plane in a cubic crystal.