As COOS technology is scaled into the sub-0.25 micrometer regime, the poly-Si gate depletion effect becomes more problematic. This paper discusses various technological approaches to eliminating this effect. It is shown that poly- SiGe is an especially promising alternative gate material because it can be integrated into an existing COOS process with relative ease. As compared to poly-Si gate technology, poly-Si0.8Ge0.2 gate technology provides improved resistance to the gate-depletion effect, improved tradeoff between the gate-depletion effect and the boron penetration problem for p-channel devices, and superior device reliability. The viability of poly-Si0.8Ge0.2 as a gate material for sub-0.25 micrometer COOS technology is demonstrated in the fabrication of 0.1 micrometer channel- length MOSFETs.