Dry etch sequencing induced gate oxide degradation due to metalliccontamination in 0.25 μm CMOS manufacturing

摘要

To ensure maximum tool utilization in high volume semiconductormanufacturing, multiple etch recipes may be implemented on a given etchchamber configuration. Due to the increased process complexity requiredfor 0.25 μm semiconductor fabrication, residual effects in chambersand interaction between etch recipes can change individual etch processoutputs. Described below is 40 Å gate oxide degradation due toresidual metallic contamination in an etch chamber caused by a previouscontact etch process, in high volume 0.25 μm CMOS manufacturing.Chamber seasoning, the specific combination of etch processes run due toproduct needs, post-etch cleans, and gate polysilicon doping all have asignificant effect on the degree of oxide degradation caused. Alsodiscussed is the impact of the degraded oxide on circuit yield andreliability