| 摘要 |
An apparatus and a method for etching high dielectric constant (high-kappa) materials using halogen containing gas and reducing gas chemistries are provided. One embodiment of the method is accomplished by etching a layer using two etch gas chemistries in separate steps. The first etch gas chemistry contain no oxygen containing gas in order to break through etching of the high dielectric constant materials, to dean any residues left from previous polysilicon etch process resulting in less high-kappa foot, and also to control silicon recess problem associated with an underlying silicon oxide layer. The second over-etch gas chemistry provides a high etch selectivity for high dielectric constant materials over silicon oxide materials to be combined with low source power to further reduce silicon substrate oxidation problem.
|
