Chapter 2. COST PER WAFER - Smithsonian - The Chip Collection

¥ Test wafer cost rises dramatically at the
200mm level as manufacturers use prime
polished wafers, rather than reclaimed
wafers, for process monitoring.
¥ Studies indicate that some fabs are spending
$1 million or more a month on test
wafers, which does not include the cost of
lost productivity when tools are running
these wafers [3] .
Conclusions
A companyÕs ability to drive down cost per
wafer requires an understanding of the cost
components. Cost competitiveness is
absolutely essential regardless of device
market due to the true globalization of
todayÕs semiconductor market.
WIP or Cycle Time
Process
Time
Manufacturing with
High Variability
Manufacturing with
Low Variability
References
Cost Per Wafer
1. J. Smits, et.al., ÒLogistics in Fab Design,Ó
Future Fab International, p. 101.
2. 1978-1995 Industry Data Book,
Semiconductor Industry Association
3. S. Billat, "Process Control: Covering All
of the Bases," Semiconductor International,
Sept. 1993, p. 78.
Loading Capacity
Source: TI 19754
Figure 2-25. The Effect of Variability on WIP and Cycle Time
INTEGRATED CIRCUIT ENGINEERING CORPORATION 2-19