To predict the dimensional performance of carriers over time, various tests were performed. This high modulus, combined with its high glass-transition temperature, results in a carrier with very stable dimensions over both time and a wide temperature range. Photographs of the backside of wafers abraded against carriers. Particle Performance Carrier resistance to abrasion was critical for selecting the new carrier and box. Of particular importance was the resistance of the carrier to abrasion by the wafers.
Particles generated from wafers abrading the carrier can directly cause defects and yield loss.
The particles generated can also adhere to the wafer backside, near the edge, and cause focus problems during lithography steps. In this test, polished-edge wafers were intentionally abraded against the carriers for 1000 insertions and extractions. Figure 2 shows the particles found on the wafer backside at the point of contact between the wafer and the carrier tooth. A team, formed to plan the conversion, consisted of personnel from both IBM and Entegris. The planning process took approximately three months.