N. Hirashita et al., THERMAL-DESORPTION AND INFRARED STUDIES OF PLASMA-ENHANCED CHEMICAL VAPOR-DEPOSITED SIO FILMS WITH TETRAETHYLORTHOSILICATE, JPN J A P 1, 32(4), 1993, pp. 1787-1793
Thermal desorption and Fourier transform infrared spectroscopies were
used to study plasma-enhanced chemical vapor deposited SiO films from
tetraethylorthosilicate. Significant water desorption and concomitant
structural changes were observed for the films during subsequent heat
treatments between 100 and 700-degrees-C. The films exhibited three di
stinct water desorption states. The desorption temperatures were appro
ximately 100-200-degrees-C for the first state, 150-300-degrees-C for
the second state, and 350-650-degrees-C for the third state. Air expos
ure experiments revealed that the first and second states resulted fro
m absorbed water and the third state from constitution water. The firs
t and second desorption states were confirmed to originate from liquid
like water and water molecules hydrogen-bonded to Si-OH bonds at macr
opore sites in the films, respectively. The third desorption state was
found to result from Si-OH bonds formed during the film growth. This
desorption of constitution water was considered to be accompanied by a
microstructural change of the films.