Page 369 - Sami Franssila Introduction to Microfabrication

348 Introduction to Microfabrication

cleanroom conditions can only be fulfilled when all sub- on a 200 mm wafer in an ISO class 2 cleanroom in
systems are running. an hour?

REFERENCES AND RELATED READINGS
35.4 EXERCISES
Baldwin, D.G., M. Williams & P.L. Murphy: Chemical Safety
1. What ISO class corresponds to Fed. Std. 209 rd
Handbook for the Semiconductor/Electronics Industry, 3
class 100 cleanroom and class 1, respectively? ed., OEM Press, Beverly Farms, 2002.
2. Make a graphical plot of ISO cleanliness classes 1 to Cheng, H.P. & R. Jansen: Cleanroom technology, in C.Y.
4 for particle sizes 0.1 to 1 µm. Chang & S.M. Sze (eds.), ULSI Technology, McGraw-Hill,
3. What class of cleanroom would be suitable for 1996.
(a) 1 µm and (b) 0.1 µm CMOS production? Middleman, S. & A.K. Hochberg: Process Engineering Anal-
4. If a 0.5 L bottle (under 50 bar pressure) of boron ysis in Semiconductor Device Fabrication, McGraw-Hill,
2
trifluoride (BF 3 ) leaks into a 1000 m cleanroom, will 1993.
it be immediately dangerous to health? Misra, A., J.D. Hogan & R.A. Chorush: Handbook of Chemi-
5. Particle deposition rate J on a wafer that is parallel cals and Gases for the Semiconductor Industry, John Wiley
& Sons, 2002.
to airflow is given by J = nu, where n is the
Rubloff, G.W. & D.T. Boronaro: Integrated processing for
particle density and u is the sum of gravitational and microelectronics science and technology, IBM J. Res. Dev.,
diffusive settling velocities, ca. 5 × 10 −4 cm/s for 0.1 36 (1992), 233.
to 0.5 µm particles. How many particles will deposit Whyte, W.: (ed.): Cleanroom Design, Wiley, 1999.