| 摘要 |
PURPOSE:To obtain the evaluating method having high reproducibility by acquiring the resistivity of an irradiating section from currents flowing at a time when beams of energy close to band gap energy are irradiated partially through a transparent electrode. CONSTITUTION:One surface of the wafer is mirror-processed through chemical and mechanical polishing and mirror chemical-etched, and the whole surface is coated with an indium-tin-oxide film 2 and the transparent electrode 2 is formed. The indium-tin- oxide film is approximately transparent to beams having energy close to the band gap energy of GaAs, and has conductivity. Gold is evaporated on the back of the wafer, and a back metallic electrode 3 is formed. The semiconductor wafer is entered in a black box under the state in which the electrodes are attached on both surfaces of the wafer, or condensed light beams 4 are irradiated to the partial section of the semiconductor wafer through the transparent electrode 2 in a darkroom. Voltage is applied previously to the two electrodes 2, 3 by a power supply 5 at that time. Currents flowing at that time differ to each other according to the position of the surface of the wafer, photo-irradiating currents also vary being affected by the inequality of resistivity in the wafer when light beams are scanned in the direction of the diameter of the wafer, and measurement of excellent reproducibility is enabled. |
