A vertical semiconductor power device includes a top surface and a bottom surface of a semiconductor substrate constituting a vertical current path for conducting a current there through. The communication device comprises: a network connection to initiate a command relating to the network after satisfaction of a predetermined condition relating to another network relating to the communication device; and a communication system to process communications between the device and the network and between the device and another network. The processing unit produces a digital model of the surface by generating segments from the spherical coordinates of the measuring points plotted and for calculating the surface area of the digital model. Since the growth surface is flat, a growth surface of the GaN epitaxial layer epitaxially grown on the intermediate layer is also flat.