Method for forming a refractory-metal-silicide layer in a semiconductor device
AssigneeNEC Corporation
InventorsNobuaki Hamanaka, Ken Inoue, Kaoru Mikagi
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Abstract
A method for forming a silicide of a metal with high-melting-point in a semiconductor device includes the step of removing a higher-density impurity area which acts for prevention of refractory-metal-silicification of diffused regions between the steps of implanting impurities to form an impurity-implanted region and annealing for refractory-metal-silicification of the diffused layer. The refractory-metal-silicification of the diffused regions proceeds smoothly to thereby prevent degradation of the initial gate withstand voltage and a higher sheet resistance.
Claims12
A method for forming a silicide of a metal with high-melting-point in a semiconductor device comprising the steps of:
- forming a gate electrode having sidewalls on both side surfaces of the gate electrode;
- then implanting impurity ions into a silicon substrate to form an impurity-implanted region;
- then heat-treating the silicon substrate to form an oxide layer on top of the impurity-implanted region;
- next etching the oxide layer for removal thereof by using a weak basic oxidant solution;
- after said etching step, heat-treating the impurity-implanted region to diffuse the impurity ions to form a heavily-doped source/drain region from the impurity-implanted region;
- subsequently depositing a metal with high-melting-point to form a metal layer on the heavily-doped source/drain region;
- and
- then heat-treating the metal layer for refractory-metal-silicification of the heavily-doped source/drain region.
A method for forming a silicide of a metal with high-melting-point in a semiconductor device comprising the steps of:
- forming a gate electrode having sidewalls on both side surfaces of the gate electrode;
- then implanting impurity ions into a silicon substrate to form an impurity-implanted region;
- then heat-treating the impurity-implanted region to diffuse the impurity ions to form a heavily-doped source/drain region from the impurity-implanted region;
- subsequently etching a top of the heavily-doped source/drain region for removal thereof by using a weak basic oxidant solution;
- after said etching step, depositing a metal with high-melting-point to form a metal layer on the heavily-doped source/drain region;
- and
- then heat-treating the metal layer for refractory, metal-silicification of the heavily-doped source/drain region.
Dependencies are inferred from the claim text.