| 摘要 |
PURPOSE:To obtain the distribution of the impurity concentration under a gate in the depth direction on the basis of the capacitance of a gate insulation film wherein an FET being measured is formed, gate length and gate width, and substrate bias dependence of the threshold voltage obtained directly from the transistor. CONSTITUTION:The curve expressed in terms of Formula I is obtained from the capacitance Co of the gate insulation film of the FET being measured in characteristics, gate length and gate width, and substrate bias voltage VSB dependence of the threshold voltage VT measured directly from the transistor; where, (q) is the charge of an electron, epsilonS the dielectric constant of a semiconductor, and N an impurity. Here, the voltage VT is measured by the viriation of the bias VSB and extrapolated to the point of Formula (DELTAVT/DELTAVSB)<-2>=0 with respect to VSB, thereby the Fermi level phiFB of the substrate is determined. On the other hand, the width W of a depletion layer is expressed in terms of Formula II, and the impurity concentration of a point at a distance in the depth direction from immediately under the gate is obtained. |
