At small potentials, the electrochemical deposition of As 3+ is slower than the diffusion of As atoms to the In interface, and no As overgrowth is expected. By contrast, if the rate of the As deposition is larger than that of the crystal growth, As will accumulate at the surface, enabling In diffusion and inhomogeneous InAs vertical growth. Additional to higher As deposition, large cathodic potentials may also increase the rate for arsine and hydrogen gas evolution. Both reactions can significantly increase the roughness/porosity of the film by (i) bubble formation, (ii) restriction of InAs growth in highly active sites for gas evolution, and, in the case of Arsine evolution, (iii) generation of As vacancies in already formed InAs.