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Zeroing the scale on the Z-micro adjust
With sample mounted to work holder and in the quick release holder with a lapping plate in place.
Zero out the dial indicator while the head has not touched the lap. This is your zero point where the
sample has not touched the lap. Bring down the head using the Z-micro adjust knob. Observe the first
moment the dial indicator reads a deflection. Turn the Z-micro adjust until the dial reads 10μm. Now
loosen the locking screw for the slippable scale and turn the slippable scale until it reads 10μm.
Tighten screw for the slippable scale. From this point on, it is possible to keep track of how much
material is removed by observing the turns when using the Z-micro adjust.
ii.
Lapping
For backside, you could use various grit size films to remove material. The typical steps for material
removal are various size diamond films in successive order as follows: 30μm, 15μm, 6μ, 3μm, and
1μm. Use the desired films for removal.
Once all steps of diamond films have been completed use the polyurethane pad and colloidal silica
(much like in the delayering process) for about 2 minutes to get the final mirror finish. Lap speed,
rotation speed, and oscillation speed can be changed to get faster results.
iii.
Die Level
For die level backside thinning, you can use the Ultracollimator to align the sample. Mount the sample
much like in the delayering process except that the topside will be facing the hole. The topside is
reflective enough to use with the Ultracollimator. After alignment, same procedure for backside
thinning is utilized, i.e. using decreasing different film grit sizes.
