Etch uniformity is improved in that a specified material layer to be etched is exposed to an ion beam so as to implant an ion species, wherein at least one implantation parameter is varied in conformity with local etch rates of the specified material layer. To the liquid crystal display panel are connected a display controlling circuit, a scanning line driving circuit, and a signal line driving circuit. A display disposed on the surface of the housing is operable to show a virtual control that initiates a second function. by reactive ion etching, so as to create vertical window walls. The channel has a width that exceeds the gap width of the slot. While the system can write a three-dimensional shape it can also be used to erase some or all of a shape.