Several carbon nanowalls (CNWs) semiconductors with different morphologies (such as length and edges presence) and internal microstructure (presence of defects, interfaces and interlayer space of graphene) reveal differences in the electrical properties. The quasi-2D walls are deposited with random orientation and each wall is formed by few graphene layers (up to 15 layers) in a vertical deposition. All CNWs samples were grown by a plasma enhanced chemical vapor deposition (PECVD) process varying deposition temperature, time and Ar flux. Scanning electron microscopy, transmission electron microscopy and Raman spectroscopy were used to substantiate the structural and morphological differences. The semiconductor behavior was demonstrated in the temperature-electrical resistance dependence. The CNW sample synthetized with more Ar flux and deposition temperature showed higher conductivity. These behaviour is explained in terms of the better charge transport in dense walls with more number of defects (that is boundaries, interfaces and atomically disorder) enhanced mainly by the deposition temperature. Our results propitiate a way towards the use of vertical graphene or CNWs as semiconductor nanodevices.