Effects of Different Si(3)N(4) Thicknesses on the Performance of PECVD SiO(2)/Si(3)N(4) Double Layers Electrets

In this paper, charge decay of PECVD SiO(2)/Si(3)N(4) double layers electrets with different thicknesses of Si(3)N(4) under different environmental conditions was investigated. Single layers of PECVD prepared SiO(2) and Si(3)N(4) were also studied. Double layers electrets exhibits better charge stability than single layer under different conditions. As for the double layers with 2nm-100nm Si(3)N(4), their charge stability at 250 degrees C is as good as each other. However, if the Si(3)N(4) thickness continues to increase, the charge stability will be decreased. Thicker layer Of Si(3)N(4) leads to better charge stability under 95%RH. Heat treatment at 250 degrees C can improve charge stability under high humidity condition, especially for double layers electrets with thin Si(3)N(4). After heat treatment at 250 degrees C for 3hrs, the PECVD SiO(2)/Si(3)N(4) double layers electrets with 50nm Si(3)N(4) show the optimized charge stability under different conditions.Engineering, Electrical & ElectronicPhysics, AppliedCPCI-S(ISTP)