METHOD OF MEASURING DIFFUSION LENGTH OF MINORITY CHARGE CARRIERS IN SEMICONDUCTORS AND TEST STRUCTURE FOR IMPLEMENTATION THEREOF

摘要

FIELD: physics.SUBSTANCE: contact electrodes which are insulated from the base layer by a dielectric layer are made in the test structure which is made on a common base layer on the surface of p-n or n-p junctions of photodiodes. The radii of contact electrodes are greater than the radii of p-n or n-p junctions of photodiodes and have a common axis of symmetry. A contact is made on the surface of the base layer. The test structure is illuminated in the absorption spectral range of the base layer on the side of contact electrodes which are not transparent for infrared radiation. Photodiode photocurrents are measured and the ratios of photocurrents of two photodiodes in the test structure are determined. Theoretical calculation of photocurrents of different photodiodes of the test structure is performed and curves of the ratio of photocurrents of photodiodes versus the diffusion length of minority charge carriers are plotted. The measured photocurrent ratios are compared with theoretical values calculated from the curves and the diffusion length of minority charge carriers is determined.EFFECT: high percentage output of infrared matrix photodetectors, simple method and high accuracy thereof.2 cl, 3 dwg