| 摘要 |
PURPOSE:To obtain the dry etching device capable of enhancing the etching rate of a gate material or increasing the selectivity with a base film by providing a sample electrode with two systems of grounded circuits. CONSTITUTION:A treatment gas is introduced in a treatment chamber 1 and the air in the chamber is exhausted to reduce the pressure to a predetermined value. To a sample electrode 2 in the processing chamber 1, a grounded circuit 6 which is grounded directly and a grounded circuit 7 grounded through a coil 7a are provided and connected through a switch 8. An opposite electrode 3 is connected to a high-frequency power source 5 through a matching device 4. A sample 9 made of an Si substrate coated with a base film of SiO2 and further a gate material of polysilicon is etched. As for the etching rate of the polysilicon, the etching rate 17 of the grounded circuit 7 becomes higher than the etching rate 15 of the grounded circuit 6 and as for the selectivity of the polysilicon and SiO2, the selectivity 16 of the grounded circuit 6 becomes larger than the selectivity 18 of the grounded circuit 7.
|
