A method of making nanosub-micron sized grains in a work piece material having a lateral side has the steps of providing a die. According to the present invention, since a surface of the back-illuminated photodiode can be stably treated, the back-illuminated photodiode can be formed to have a low dark current, a constant sensitivity of blue light for all photodiodes, and high sensitivity. The vane wheel having a plurality of turbulators is embodied on at least one of the walls of the cooling channel, the turbulators being configured in such a way that the turbulence and thus the heat transfer of a cooling fluid flowing through the cooling channel are increased.