| 摘要 |
PURPOSE:To measure the thickness of the thin semiconductor layer simply and accurately by conducting the measurement of layer resistance through a four-probe method and the measurement of spread resistance using two probes about the semiconductor layer and computing and displaying the thickness from measuring results. CONSTITUTION:The layer resistance rhos is measured through the four-probe method about an inverse conduction type epitaxial layer 2 formed on a base body 1. The spread resistance R is measured by means of probes such as two probes at the inside among four probes. These measuring values are calculated according to a known relationship formula between applied voltage and currents. When the resistivity of the semiconductor layer is rho and the thickness t, and a tip of the probe made a circle with a its radius, two formulae of rhos=rho.t and p=2a.R hold. Accordingly, the values of rhos and t can be computed and displayed or printed. Consequently, the thickness and layer resistance of the thin semiconductor layer with t thickness can be measured by means of one measuring device. |
