Page 192 - Microsensors, MEMS and Smart Devices - Gardner Varadhan and Awadelkarim

172 SILICON MICROMACHINING: SURFACE

6.8 SURFACE VERSUS BULK MICROMACHINING

In this chapter and the previous one, we have described the use of bulk and surface
micromachining to fabricate microsensors and MEMS devices. Table 6.1 summarises
the relative advantages and disadvantages of these two technologies. Perhaps the most
attractive feature is whether the technique may be readily combined with a standard 1C
process - ideally as simple pre- or postprocessing steps. In this respect, a front side surface
micromachining is perhaps the most attractive current option. However, the possibility
of a front side bulk etch of a silicon-on-insulator (SOI) CMOS device may become a
cost-effective and desirable option in the near future. The use of a micromachined SOI
membrane to make a smart gas sensor is discussed later (Section 15.2).

REFERENCES

Farooqui, M. M. and Evans, A. G. R. (1992). "Microfabrication of submicron nozzles in silicon
nitride," J. Microelectromech. Syst., 1, 86–88.
Gardner, J. W. (1994). Microsensors: Principles and Applications, John Wiley & Sons, Chichester,
p. 331.
Guckel, H., Sniegowski, J. J., Christenson, T. R. and Raissi, F. (1990). Sensors and Actuators A,
346, 21–23.
Hirano, T., Furuhata, T., Gabriel, K. J. and Fujita, H. (1991). Technical Digest of 6th Int. Conf.
Solid-State Sensors and Actuators, San Francisco, USA, pp. 63–66.
Hirano, T., Furuhata, T., Gabriel, K. J. and Fujita, H. (1992). "Design, fabrication, and operation
of submicron gap comb-drive microactuators," J, Microelectromech. Syst., 1, 52–59.
Kim, C-J., Pisano, A. P., Muller, R. S. (1992). "Silion-processed overhanging microgripper,"
J. Microelectromech. Syst., 1, 31–35.
Kung, J. T. and Lee, H-S. (1992). "An integrated Gir-gap-capacitor pressure sensor and digital
read-out with sub-100 attofarad resolution," /. Microelectromech. Syst., 1, 121–129.
Linder, C. et al. (1992). "Surface micromachining," J. Micromech. Microeng., 2, 122–332.
Mastrangelo, C. H. and Saloka, G. S. (1993). "An investigation of micro structures, sensors actu-
ators machines and systems," J. Microelectromech. Syst., 77–81.
Mehregany, M. and Tai, Y-C. (1991). "Surface micromachined mechanisms and micromotors,"
J. Micromech. Microeng., 1, 73–85.
Robbins, W. P. et al. (1991). "Design of linear-motion microactuators using piezoelectric thin
films," J. Micromech. Microeng., 1, 247–252.
Scheeper, P. R., van der Donk, A. G. H., Olthuis, W. and Bergveld, P. (1992). "Fabrication of
silicon condenser microphones using single wafer technology," J. Microelectromech. Syst., I,
147–154.