which form individual luminescent micro lamps in fig1 and 2 the cavities 18 are depicted as generally spherical and the substrates 12 and 14 are depicted as circular in plan view it should be kept in mind that the cavities and substrates may be of any size and shape the substitutes are depicted as circular since handling equipment for circular plates is readily available from numbers of integrated circuit manufacturing equipment cavities 18 may be square rectangular or elongated channels fig1 illustrates a lamp constructed in accordance with the present invention in its simplest embodiment that of an electrodeless rf activated lamp the steps of manufacturing the lamp will also be discerned from this figure planar substrate 14 is transparent and consists of material suitable for containing the pressure and temperature of an operating lamp one such suitable material is quartz cavity 18 which comprises a half cavity 20 in substrate 14 and a half cavity 22 in substrate 12 is formed by integrated circuit manufacturing techniques the upper surface 24 of un etched substrate 14 is covered by suitable masking material such as polysilicon at the portions where etching is not desired as etching will occur at the unmasked portions thereafter the masked substrate is exposed to an etchant such.