Pulse-time modulated ECR plasma etching for highly selective, highly anisotropic and less-charging poly-Si gate patterning

This paper proposes a new electron cyclotron resonance (ECR) plasma etching for precise gate electrode patterning in future ULSI circuits such as 1 Gbit DRAM. In this technology, 10 /spl mu/sec pulse-time modulated microwaves are introduced into the plasma chamber. The ECR plasma etching technique achieves highly selective (/spl ges/100), high-rate (/spl ges/3000 /spl Aring//min), highly anisotropic (even at 100% over-etching), notching-free and less-charging submicron poly-Si patterning.<>