tin oxide or tin oxide and has a transparent insulating material 3 such as silicon dioxide disposed thereon tantalum oxide and salicided materials can also be used to form the insulating material 3 if the electrodes 2 are not fabricated from a substantially transparent material large portions of the electrodes 2 should still be substantially transparent one advantage of the use of a silicon dioxide layer 3 according to the present invention is the increase in the height of the stack for practical formation of etched spacers 4 if the stack which is to be etched is higher there is more flexibility in terms of the etch parameters particularly etch uniformity and degree of overetch the electrodes 2 have a height substantially within the range of 1000 u00e5 5000 u00e5 in an alternative embodiment see for example fig5 the transparent silicon dioxide layer 3 is not used in such a case the etch step becomes more difficult because the conductive transparent electrode 2 is usually very small and may be eroded during the overetch portion of the etch step the insulating layer 3 lends more leeway to the etch step and thereby makes the process of the present invention more commercially practical the substrate 1 can be any of a variety of materials known in the art and the selection of the substrate 1 may be related to cost as well as to the type of.