The present disclosure is broadly directed to a method for designing new
MEMS micro-movers, particularly suited for, but not limited to, CMOS
fabrication techniques, that are capable of large lateral displacement
for tuning capacitors, fabricating capacitors, self-assembly of small
gaps in CMOS processes, fabricating latching structures and other
applications where lateral micro-positioning on the order of up to 10
.mu.m, or greater, is desired. Principles of self-assembly and
electro-thermal actuation are used for designing micro-movers. In
self-assembly, motion is induced in specific beams by designing a lateral
effective residual stress gradient within the beams. The lateral residual
stress gradient arises from purposefully offsetting certain layers of one
material versus another material. For example, lower metal layers may be
side by side with dielectric layers, both of which are positioned beneath
a top metal layer of a CMOS-MEMS beam. In electro-thermal actuation,
motion is induced in specific beams by designing a lateral gradient of
temperature coefficient of expansion (TCE) within the beams. The lateral
TCE gradient is achieved in the same manner as with self-assembly, by
purposefully offsetting the lower metal layers with layers of dielectric
with respect to the top metal layer of a CMOS-MEMS beam. A heater
resistor, usually made from a CMOS polysilicon layer, is embedded into
the beam or into an adjacent assembly to heat the beam. When heated, the
TCE gradient will cause a stress gradient in the beam, resulting in the
electro-thermal actuation. Because of the rules governing abstracts, this
abstract should not be used to construe the claims.