Vacuum-sheath interconnect structure for dense memory

A novel mostly-air interconnect structure is proposed. Every metal line is surrounded by an air vacuum sheath on all sides and supported on the bottom by a series of solid dielectric beams. The vias are also surrounded by vacuum sheaths. Computer simulation shows that the total capacitance of the interconnect is reduced by about 45% and the RC delay is decreased about 55%. The effective dielectric constant can be reduced to about 1.7 using existing dielectric with k%2.9.