Etching high-kappa dielectric materials with good high-kappa foot control and silicon recess control
First Claim
1. A method of plasma etching a substrate having a layer containing a high-κ
- material, comprising;
exposing the layer to a plasma formed from a first process gas mixture comprising a first halogen containing gas without introducing an oxygen containing gas inside an etch chamber;
etching at least a portion of the layer in a first etch step; and
etching the layer in a second etch step using a plasma formed from a second process gas mixture comprising a second halogen containing gas and carbon monoxide.
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Accused Products
Abstract
An apparatus and a method for etching high dielectric constant (high-κ) 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-κ 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.
201 Citations
24 Claims
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1. A method of plasma etching a substrate having a layer containing a high-κ
- material, comprising;
exposing the layer to a plasma formed from a first process gas mixture comprising a first halogen containing gas without introducing an oxygen containing gas inside an etch chamber;
etching at least a portion of the layer in a first etch step; and
etching the layer in a second etch step using a plasma formed from a second process gas mixture comprising a second halogen containing gas and carbon monoxide. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- material, comprising;
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16. A method of plasma etching a substrate having a layer containing a high-κ
- material, comprising;
etching at least a portion of the layer with a plasma formed from a first process gas mixture comprising a first halogen containing gas at a substrate bias power of 100 W or less inside an etch chamber; and
etching the layer with a plasma formed from a second process gas mixture comprising a second halogen containing gas and carbon monoxide with a selectivity for the layer and at a source power of between about 200 W to about 800 W. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
- material, comprising;
Specification