Amorphous Diamond Dresser for CMP Fixed Abrasives Pad
The primary consumables in chemical mechanical polishing (CMP) are the polishing pad and slurry. The polishing pad significantly influences the stability of the polishing process and the cost of consumables (CoC). Usually a diamond pad conditioner is used to scrap off the polishing debris from the pad top. Recently, an alternative planarization process can be achieved by polishing with a "fixed abrasive pad" (FAP). In order to dress bumps on FAP, this paper use an amorphous diamond, a diamond-like carbon deposited by cathode arc system as the dresser for FAP. The amorphous diamond can produce a surface relief that ranges from a few nanometers to about 200 nanometers. With the addition of this dressing step on a rotary platform, FAP can renew its polishing surface 10 to 100 times before the bumps are used up. The pad cost for polishing can be reduced by at least ten folds and make FAP more desirable than slurry pad for silicon wafer manufacturer due to its intrinsic capabilities to produce flatter wafers with high polishing rate.
Dongming Guo, Tsunemoto Kuriyagawa, Jun Wang and Jun’ichi Tamaki
P. L. Tso and Y. L. Pai, "Amorphous Diamond Dresser for CMP Fixed Abrasives Pad", Key Engineering Materials, Vol. 329, pp. 157-162, 2007