NONNCONTACT MEASUREMENT OF SEMICONDUCTOR CARRIER CONCENTRATION AND CONDUCTIVITY BY CAPACITANCEECOUPLING

摘要

PURPOSE:To provide a simple and practical method for measuring the carrier concentration of a specimen by means of capacitance-coupling detection using electrodes placed close to the specimen. CONSTITUTION:Four plate-shaped electrodes 1-4 of arbitrary shape, fitted with thin dielectric film on their surface, are arranged in a plane in a ring form. Specimen 5 is mounted on all of these electrode. When high-frequency voltage 6 is impressed on any two opposing electrodes, of these four, high-frequency current I flows in the specimen via the capacitance between the electrodes and the specimen. This current I is read by ammeter 7. Next, when magnetic field B is set up in the direction perpendicular to the plane of the electrodes, hole voltage VH is generated in the direction perpendicular to the straight line connecting electrodes 1 and 3. This hole volgate VH is capacitance-coupling-detected by electrodes 2, 4 and voltmeter 8. Then, it becomes that hole voltage VH=KBI/ent (e denotes electron charge, t specimen thickness). The proportionality constant K is determined by a specimen of known carrier concentration, and the carrier concentration n of the specimen under measurement is obtained.