Authors: Birnie, D.P. III; Vogt, R.N.; Orr, M.N.; Schifko, J.R.
Source: Microelectronic Engineering 29 (1995) 189-192
Abstract: Important coating characteristics are discussed with
an emphasis on understanding their impact on device reliability. The sources
of thickness variations in relationship to the processing conditions imposed
during spin coating and subsequent firing are described. In particular,
evaporation of volatile solvents during spinning can cause thickness striations
and vacuum-chuck marks. In addition, the crystallized microstructure may
not be completely uniform, depending on the uniformity of substrate nucleation
locations. These variations will impact the electrical reliability of the
PZT devices which are made from these films. Thinner regions will have
higher capacitance, but will be more susceptible to electrical degradation
over time. Also, the scale of size uniformity in the microstructure can
impact attempts to make smaller devices.