| 摘要 |
PURPOSE:To measure distribution in the depth direction of impurity concentration regardless of the kinds of transistors by calculating the distribution from the ratio of the change of gate voltage to the change of drain currents and the relationship of depth from the surface of a substrate and substrate bias. CONSTITUTION:The ratio of gate voltage VG when the substrate bias Vb of a transistor is changed to the change of drain currents represented by a logarithm is measured, and the relationship of each bias Vb and formula I is plotted and a curve is obtained. A slope at the bias Vb of the curve is acquired, and impurity concentration is each calculated from formula II. Each depth X is calculated from formula III by introducing each bias Vb and N to the Vb. Where A, B, D represent constants given from a temperature, size, etc. |
