HALL EFFECT ANALYSIS OF CHARGE TRANSPORT IN SILICON DIOXIDE-SILICON NITRIDE DOUBLE LAYERS.

A method to obtain respective fields in multilayers is proposed. The samples investigated are large-area n-channel transistors (L equals 1. 38 mm, W equals 1 mm) with Hall terminals, which have poly-Si (P-doped)/7. 5 nm-SiO//2 (thermally oxidized)/6. 3-nm-Si//3N//4/p-Si-substrate structures. In order to ensure steady-state conditions, the measurements were carried out 5 min. after decreasing gate voltage V//G stepwise. Magnetic field H (5. 2 kGauss) was imposed perpendicular to substrates. Hall voltage V//H is related to the surface charge density Q//s by Q//s equals rHI//D/V//H(r: Hall ratio, I//D: drain current). The nitride field E//Nis obtained as E//N equals (Q//D plus Q//S/ epsilon //N, where Q//D is depletion layer charge density, and epsilon //N is static dielectric constant of nitride. The oxide field E//0 is calculated as follows, assuming that the centroid of trapped charges Q//N in the nitride is at oxide-nitride interface.