FRACTAL PROPERTIES OF MICROPLASMA BREAKDOWN AND STRUCTURAL HETEROGENEITY OF SEMICONDUCTOR MATERIALS

This work presents experimental results on the study of current-voltage characteristics and oscillograms of microplasma pulses of the p-n-junction avalanche breakdown. Based on the latter, the pulse duration distributions are determined. As a result, it is shown that microplasma noise has fractal properties. The latter form the basis of avalanche breakdown types developed classification. The correlation between the fractal dimension of microplasma noise and structural inhomogeneities of functional semiconductor structures is revealed.

Влияние глубоких центров на статистическую задержку микроплазменного пробоя в арсенид-галлиевых светодиодах

A statistical study of the microplasma-breakdown delay in gallium-arsenide light-emitting diodes is performed. The significant effect of deep centers on the microplasma breakdown of gallium arsenide p–n junctions is detected. It is shown that the statistical delay of the microplasma breakdown makes it possible to estimate the energy spectrum of deep levels in the microplasma channel when varying the charge state of deep centers by decreasing the reverse voltage applied to the p–n junction. In the temperature range of 250–350 K, the effect of three deep levels is detected and their parameters are determined.

Characterization of Screw Dislocations in a 4H-Silicon Carbide Diode Using X-Ray Microbeam Three-Dimensional Topography

This paper describes the study of non-hollow-core elementary screw dislocations (SDs) in silicon carbide (SiC) diodes using X-ray microbeam three-dimensional topography. Strain analysis shows that typical screw dislocations having a symmetric strain field tend to cause microplasma breakdown, whereas deformed SDs do not. The symmetry break in SDs will relax the focussing of strain and lessen the formation of defects, thereby leading to the desirable non-leak property.

Investigation Of Microplasma Breakdown In 4H Silicon Carbide

ABSTRACTReverse bias breakdown behaviour of high quality 4H silicon carbide p-n diodes was investigated, using optical and electrical measurement techniques. Most of the sample diodes suffered from early breakdown phenomena in the form of microplasmas at about 80% of the calculated parallel plane breakdown voltage for the diodes, as evident from measured I-V curves. A group of these microplasmas could be correlated to micropipes, identified by optical microscopy, while a large number of microplasmas were caused by other defects and inhomogenities in the space charge region under reverse bias. The same spots that revealed early breakdown phenomena under reverse bias also showed a different electroluminescence (EL) behaviour under low forward current densities compared to those areas with a homogeneous breakdown behaviour. However, even diodes containing one or more micropipes in the region of the junction showed good rectifying behaviour up to two third of the parallel plane breakdown voltage, where the turn-on of a microplasma was observed.