A new water permeability sensor based on the sensitivity of polyimide
to humidity has been fabricated for the measurement of the water penet
ration of thin metal films. To evaluate the sensitivity of the polyimi
de layer a special humidity sensor was also fabricated. This humidity
sensor demonstrates good linearity, a relatively fast response time (1
.5-2 min), and good sensitivity. To evaluate the permeability sensor a
5000 Angstrom gold film with a pinhole density of approximately 100 p
er cm(2) was measured. The results show a capacity change from 100 to
109 pF and saturation after 300 h.