Abstract: A porous semiconductor is created by electrochemical etching. Selected regions of a semiconductor are first treated to reduce the threshold potential at which pore formation occurs, and then an electrochemical etch is carried out on the semiconductor at a potential at least equal to the reduced threshold potential for the selected regions and less than the threshold potential for untreated regions. The selective treatment preferably involves implantation with the same ions as the semiconductor, i.e. Si ions for silicon. The treatment results in the formation of highly defined etch patterns or patterns of porous material depending on the process conditions.

Abstract: The first object of the present invention is to provide a PDP with improved panel brightness which is achieved by improving the efficiency in conversion from discharge energy to visible rays. The second object of the present invention is to provide a PDP with improved panel life which is achieved by improving the protecting layer protecting the dielectrics glass layer. To achieve the first object, the present invention sets the amount of xenon in the discharge gas to the range of 10% by volume to less than 100% by volume, and sets the charging pressure for the discharge gas to the range of 500 to 760 Torr which is higher than conventional charging pressures. With such construction, the panel brightness increases. Also, to achieve the second object, the present invention has, on the surface of the dielectric glass layer, a protecting layer consisting of an alkaline earth oxide with (100)-face or (110)-face orientation.