Enhanced self aligned contact (SAC) etch stop window by using C/sub 4/F/sub 6/ chemistry

A self-aligned contact (SAC) process with C/sub 4/F/sub 6/ based chemistry has been developed for device technologies of 0.13 /spl mu/m and beyond using eMax-an advanced dielectric etch system utilizing MERIE technology. Higher nitride selectivity and a wider etch stop window have been achieved. The new SAC process is capable of etching both low and high aspect ratio SAC structures with up to 30:1 nitride corner selectivity, greater than 87/spl deg/ profile, with up to 6500 A/min etch rate. Process trends versus key parameters have been characterized and CO addition effects on nitride selectivity and profile were also evaluated. A stable process performance has been demonstrated with an extended run of 122 RF hours and more than 5288 wafers.