A Rh/Au/Rh rigid air-bridge interconnection technique for ultra-high speed GaAs LSIs

A rhodium/gold/rhodium (Rh/Au/Rh) air-bridge interconnection has been developed for applying to ultra-high-speed GaAs LSIs. This structure is suitable for forming a mechanically strong air-bridge interconnection, which enables an interconnection length to be expanded without many support-pillars, compared with a gold air-bridge interconnection. This contribution of the air-bridge interconnection to total propagation delay time in a GaAs LSI chip is quantitively investigated. It is found that applying the air-bridge interconnection to a GaAs LSI with 10 K-gate complexity causes total delay time to be reduced to 65%, compared with the conventional interconnection.<
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