Back-Ground Current Error Compensation for Measurement of Ultra-High Resistance Nano Films' Insulation Characteristics

摘要

Ultra-high resistance measurement is of great importance in performance test for nano dielectric films. Time-varying nonlinear background current is usually an excess current across the device under test, which makes normal standard test method inaccurate. A novel back-ground current error compensation method is proposed in this study report to reduce this effect. Nth order non-linear background current model was firstly established and then measurement formulation derived from n + 2 groups of observed electrometer output signals by applying high test voltage with alternating polarity. Two compensation algorithms were introduced according to the background current mechanism, to obtain actual current from DUT without background current terms. Results from the experiments showed that measurement uncertainty (k = 2) of 100 CR Nano Film was lower than +/-3.5% with 100 V testing voltage. Meanwhile, the measurement settling time caused by intrinsic dielectric dissipation was shortened from 30 minutes to 4 minutes. The insulation tests demonstrated that this method can improve the accuracy and enlarge test range for ultra-high resistance Nano Films measurement.