FABRICATION OF SEMICONDUCTOR DEVICES WITH AIR GAPS FOR ULTRA LOW CAPACITANCE INTERCONNECTIONS AND METHODS OF MAKING SAME

A METHOD OF FORMING AN AIR GAP OR GAPS WITHIN SOLID STRUCTURES AND SPECIFICALLY SEMICONDUCTOR STRUCTURES TO REDUCE CAPACITIVE COUPLING BETWEEN ELECTRICAL ELEMENTS SUCH AS METAL LINES, WHEREIN SACRIFICIAL MATERIAL (20) IS USED TO OCCUPY A CLOSED INTERIOR VOLUME IN A SEMICONDUCTOR STRUCTURE IS DISCLOSED. THE SACRIFICIAL MATERIAL (20) IS CAUSED TO DECOMPOSE INTO ONE OR MORE GASEOUS DECOMPOSITIOR PRODUCTS WHICH ARE REMOVED, IN ONE EMBODIMENT BY DIFFUSION, THROUGH AN OVERCOAT LAYER (24). TB DECOMPOSITION OF THE SACRIFICIAL MATERIAL (20) LEAVES AN AIR GAP OR GAPS (26) AT THE CLOSED INTERIOI VOLUME PREVIOUSLY OCCUPIED BY THE SACRIFICIAL MATERIAL (20). THE AIR GAPS MAY (26) BE DISPOS& BETWEEN ELECTRICAL LEADS TO MINIMIZE CAPACITIVE COUPLING THEREBETWEEN. ALSO DISCLOSED ARE METHODS OF FORMING MULTI-LEVEL AIR GAPS (26) AND METHODS OF FORMING OVER-COATED CONDUCTIVE LINES OR LEATH WHEREIN A PORTION OF THE OVERCOATING (24) IS IN CONTACT WITH AT LEAST ONE AIR GAP.(FIG 1D)