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Semiconductor Physics, Quantum Electronics & Optoelectronics. 2016. V. 19, N 4. P. 366-370.
Theoretical and experimental modelling the specific resistance
of vertical ohmic contacts Au–Ti–Pd–n+-n-n+-Si in IMPATT diodes
1V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
41, prospect Nauky, 03680 Kyiv, Ukraine; e-mail: konakova@isp.kiev.ua
Abstract. The method of electrophysical diagnostic of n+-n-n+ structures at the etching stage of manufacturing process of power IMPATT diodes has been proposed. A numerical method for specific contacts resistance calculation of vertical ohmic contacts with a non-uniform doping level has been developed. Vertical ohmic contacts Au–Ti–Pd–n+-n-n+-Si both before and after etching were used for experimental checking this model. It has been computed the value of contact resistance in the interface metal–n+ with correction of contribution of n+-n and n-n+ resistances to the total resistance. The values of total effective resistances of vertical ohmic contacts Au–Ti–Pd–n+-n-n+-Si may be calculated using the Cox–Strack method. We used solutions of Laplace’s equation for computation of specific contact resistance metal–n+ without contribution of interfaces n+-n and n-n+. The values of specific contact resistance were ~10-6 Ohm∙cm2. This method allows to control the manufacture process by monitoring the changes in electrophysical properties of the structure between etching cycles.
Keywords: specific contact resistance, IMPATT diodes, electrophysical diagnostic, ohmic contacts.
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