ABSTRACT
Solids can be deposited onto a substrate from a liquid, a plasma, a gas, or a solid state. These additive techniques are often accompanied or followed by thermal processing to obtain desired materials properties and substrate adhesion. Although deposition methods, especially in the thin film arena, are generally the same as in integrated circuits (ICs), additive processes in miniaturization science span a much wider range from inorganic to organic materials. Besides the typical microelectronic elements (Si, Al, Au, Ti, W, Cu, Cr, O, N, and Ni-Fe alloys), miniaturization science involves deposition of several atypical elements such as Zr, Ta, Ir, C, Pt, Pd, Ag, Zn, and Nb (Inset 3.1). Moreover, a plethora of exotic compounds ranging from enzymes to shape memory alloys and from hydrogels to piezoelectrics are used. The number of materials and compounds involved in IC fabrication, in comparison, is very limited. In miniaturization science, particularly in chemical sensors and biomedical devices, modular, thick film technologies are more prevalent.
