Moisture and ionic impurities play a major role in the failure mechanism of integrated devices.  The use of organic polymers as microelectronic coatings offers advantages in improved planarization of metal steps, low temperature processibility, and reduction of mechanical stresses.  Cited disadvantages are the high inherent moisture absorption and level of impurities. Polymers introduce levels of moisture and impurities 10–100 times greater than vacuum deposited inorganic insulators. Moreover, the combination of ionic impurities and a high humidity environment will degrade attractive polymer properties such as high resistivity and low dielectric constant.