Studies of Response of Metal - Porous Silicon Structures to Microwave Radiation

Abstract

Metal – porous silicon structures started to be analyzed right after the unique features of porous silicon have been found. The basis for this were researches aimed at getting efficient light radiating diodes, photodetectors, various chemical, biochemical and medical sensors etc. [1]. As a rule these structures contained Schottky barriers or p-n junctions. We produced and analyzed metal – porous silicon structures that differed from those analyzed earlier in that they did not contain the abovementioned barriers. Besides, these structures were for the first time used for a new purpose as elements to sense microwave radiation. Layers of porous silicon were produced using an ordinary method of electrochemical etching of monocrystal p-type silicon, ρ = 0.4 Ohm⋅cm, plates in electrolyte consisting of hydrofluoride acid and ethanol at the ratio 1 : 2. During the etching cycle we formed the upper contact layer and then the main layer of porous silicon. By modulating the current density during the etching cycle we aimed the porous silicon to be denser in the contact layer than in the main, more extended layer. We doped the porous layer with boron in order to get a thin p +