Dielectric relaxation in chemical vapor deposited phosphosilicate glasses

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Abstract
Dielectric properties of phosphosilicate glass (PSG) films deposited by chemical vapor deposition are studied in detail. Combined admittance measurements and flatband voltage shift measurements under bias‐temperature stress on Al‐PSG‐Si capacitors allowed us to determine the dipolar relaxation time over more than nine decades of time. Experimental results are discussed in terms of a double‐well potential model for the dipolar units with a Gaussian distribution in the logarithm of the relaxation time. Barrier height, barrier height spread, and attempt‐to‐escape frequency were determined to be 1.03 eV, 80 meV, and 2.6×1013 s−1, respectively. Evidence of nonlinear dielectric response was found at low temperature (room temperature) and high electric field (5 MV/cm). A value of 1.3 D units for the dipole moment was determined. The dielectric susceptibility was found to increase linearly with the phosphorus concentration in glass. The elementary dipole appears strictly associated with a single phosphorus atom (or molecular group containing a single phosphorus atom) rather than with more complex phosphorus units.