Method of reducing capacitance across inner leads

The method and structure are, to form an oxide layer and a first barrier layer on each metal interconnector, then to deposit an internal metal electrolytic layer on the first barrier layer, which is grinded to the first barrier layer by chemical-mechanical grinding method and eached within thickness of the oxide layer, then to form an interval wall on upper sections to two sides of each metal interconnector with oxide layer and first barrier layer, thus to form an air gap in interval of adjacent interconnector with higher aspect ratio by removing first interal metal electrolytic layer betweenadjacent interconnector and depositing a second internal metal electrolytic layer.