Method of making a polycide gate using a titanium nitride capping layer
AssigneeKabushiki Kaisha Toshiba
InventorTakeo Maeda
Life of this patent
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Abstract
A semiconductor device has a multilayer comprising a refractory metal silicide and a metal nitride on a silicon layer. The metal nitride prevents the silicon layer from being oxidized so that a good ohmic contact is obtained. A method of manufacturing the semniconductor device comprises steps of forming a polysilicon layer, implanting impurity ions into the polysilicon, removing a self oxidation film from the polysilicon layer, sequentially forming refractory metal and its nitride, patterning, and silicifying the metal. The method provides a semiconductor device having a good ohmic contact, a reduced resistivity of interconnections and high reliability.
Claims9
A method of manufacturing a semiconductor device comprising the steps of:
- forming a polysilicon layer on a silicon substrate through a gate oxide film;
- implanting impurity ions into said polysilicon layer and diffusing said impurity ions;
- removing a self oxidation film formed on said polysilicon layer after diffusing said impurity ions;
- sequentially forming, on said polysilicon layer with said self oxidation film removed, a refractory metal layer and a nitride layer of the refractory metal;
- patterning said polysilicon layer, said refractory metal layer and said nitride layer of the refractory metal into a desired shape;
- silicifying said refractory metal layer through a heat process;
- and
- removing said nitride layer after said silicifying.
A method of manufacturing a semiconductor device comprising the steps of:
- forming a polysilicon layer on a silicon substrate through a gate oxide film;
- implanting impurity ions into said polysilicon layer and diffusing said impurity ions;
- removing a self oxidation film formed on said polysilicon layer after diffusing said impurity ions;
- sequentially forming, on said polysilicon layer with said self oxidation film removed, a silicified layer of a refractory metal and a nitride layer of the refractory metal;
- patterning said polysilicon layer, said silicified layer of the refractory metal and said nitride layer of the refractory metal into a desired shape;
- and
- removing said nitride layer after said patterning.
Dependencies are inferred from the claim text.