| 摘要 |
PURPOSE: A method for forming plug is provided to improve a reliability of semiconductor devices by easily forming plugs having a low etch loading effect, a low plug loss and a high step coverage. CONSTITUTION: An insulating layer(3) is formed on a semiconductor substrate(1) having a plurality of impurity diffusion layers(2). Contact windows are formed on the impurity diffusion layers(2) by selectively etching the insulating layer(3). After forming a polysilicon layer on the insulating layer(3), polysilicon plugs(5a,5b) are formed by etch-back the polysilicon layer. At this time, the processing gas of the etch-back procedure is used as mixed gases of SF6 gas and at least one gas of N2, O2, SO2, or N2O. The supply power is 4000 Watt more than and the bias power is 100 Watt more than. Also, the etching selectivity between the polysilicon layer and the insulating layer(3) is 5:1 less than.
|
