Deep silicidation of a polysilicon gate electrode following high temperature annealing of a source/drain under the gate may damage the gate oxide. This damage is prevented by forming the gate electrode as two polysilicon layers separated by a chemical oxide. During annealing the chemical oxide prevents the grains of one polysilicon layer from merging with the grains of the other polysilicon layer. Thereafter, silicidation is substantially confined to the top polysilicon layer, the low resistance of which shunts the bottom polysilicon layer through the chemical oxide.