Abstract:
The process of the Pd-assisted etching of silicon in a solution containing HF and H$_2$O$_2$ is investigated. It is shown that the morphology of the forming layers is affected by such factors as the etching duration and solution temperature. It is shown that Pd nanoparticles remain on the walls and bottom of the pores in the course of Pd-assisted etching. Such a structure, as is shown in earlier works, possesses the electrooxidation property of ethanol, which gives grounds to affirm that the forming structures are Schottky-type structures. A model of Pd-assisted etching is determined with the help of the electrochemical equilibrium diagram in the Si–HF(aq.) system. It is shown that the polishing dissolution of Si occurs without the formation of intermediate products (SiO$_2$).
Keywords:porous silicon, metal-assisted chemical etching, MACE, palladium nanoparticles.