CMP Machine with Controlled Polishing for Process Development and Polishing Materials Functional Testing

CMP process optimization and functional testing on consumables are expensive to perform on large production CMP machines. The novel bench-top CMP machine mod. CP-4 serves for efficient process development and testing of consumable materials, as well as planarization of MEMS wafers.



The main assemblies are as follows:

- self-leveling upper head with both rotational and linear motions (vertical for loading and unloading, horizontal for oscillating), which holds a wafer, or wafer coupon 0.5” to 4” *Note: wafer coupon cutter is included as a separate unit.

- mechanical servo-controlled loading programmable from 5 to 500 N, thus producing down-pressures from 0.05 to 500 psi,

- self-leveling upper holder with both passive rotation and horizontal oscillations, which holds a conditioner from 0.5” to 4.25”,

- rotational lower platen for a polishing pad from 4” to 9”,
*Note: pad coupon cutter is included as a separate unit.

- slurry feeding and draining.


 

 

The computerized real-time motor-control and data-acquisition allows for a repeatable CMP process with crucial process parameters monitored and analyzed in-situ, real-time:

1. Dynamic coefficient of friction between both wafer-pad and conditioner-pad, changes of which allow for evaluation of material removal rate and non-uniformity of polishing,

2. Energy and peaks of contact high-frequency acoustic emission, which allow for detection evaluation of polishing intensity and detection of micro-scratches and delamination,

3. Process temperature in the slurry and on the pad,

4. Pad deformations and wear.


Friendly Windows user interface (choices of Windows 95, 98, 2000 or NT) allows to easily program sophisticated test sequences with changes in load, speed and direction of multiple motions, as well as signal monitoring and analysis.


Advantages of Process Development and Materials Testing on the Bench-top Machine mod. CP-4:
 



1. The multi-sensing technology allows for monitoring polishing processes on wafers with any layers, including sensitive measurements of the material removal and its uniformity. These novel in-situ measurements with no need for post-polish metrology ensure effective process development with dramatically reduced time and so much faster time-to-market.

2. The unique accuracy and repeatability of the measurements allows for effective qualification, incoming inspection and ongoing functionality testing of polishing pads, slurries, conditioners, retaining rings.

3. The capability to accommodate small wafers and pads with small amounts of slurry make cost of testing much smaller than that on full-scale production CMP machines. The polishing process is guaranteed to produce the same material removal as on the target production CMP machine.

4. The high reliability of the machine with MTBF of order of magnitude higher than that of full- scale production CMP machines contributes to the low cost of ownership.