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US 7,582,931 B2Granted
Recessed gate electrodes having covered layer interfaces and methods of forming the same
AssigneeSamsung Electronics Co., Ltd.
InventorsByung-Hak Lee, Chang-Won Lee, Hee-Sook Park, Woong-Hee Sohn, Sun-Pil Youn, Jong-ryeol Yoo
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Abstract
A gate electrode of a transistor can include an interface between a polysilicon conformal layer and a tungsten layer thereon in a trench in a substrate and a capping layer extending across the trench and covering the interface. Related methods are also disclosed.
Claims5
A gate electrode of a transistor comprising:
- an interface between a polysilicon conformal layer on an inner wall of a trench in a substrate to provide a recess surrounded by the polysilicon conformal layer and a tungsten layer in the recess, wherein the polysilicon conformal layer extends upwardly from a surface of the substrate to have a protrusion and the protrusion has a vertical outer sidewall adjacent the surface of the substrate;
- a gate insulating layer in the trench between the polysilicon conformal layer and the inner walls of the trench;
- a thermal oxidation layer on the outer sidewall of the protrusion and the gate insulating layer at an edge of the opening of the trench;
- and
- a capping layer extending across the trench and covering the interface;
- wherein the capping layer is in direct contact with top surfaces of the polysilicon conformal layer and the tungsten layer without any intervening layers.
3 more elements
A gate electrode of a transistor comprising:
- a trench in a substrate;
- a gate insulating layer lining the trench;
- a polysilicon conformal layer, in the trench on the gate insulating layer, to provide a recess surrounded by the polysilicon conformal layer, wherein the polysilicon conformal layer extends upwardly from a surface of the substrate to have a protrusion and the protrusion has a vertical outer sidewall adjacent the surface of the substrate;
- a tungsten layer in the recess on the polysilicon conformal layer, wherein the polysilicon conformal layer and the tungsten layer produce an interface therebetween;
- a thermal oxide layer on the outer sidewall of the protrusion and the gate insulating layer at an edge of the opening of the trench;
- a capping layer extending across the trench and covering the interface;
- and
- a spacer adjacent the capping layer on a sidewall thereof covering the thermal oxide layer and the sidewall of the capping layer;
- wherein the capping layer is in direct contact with top surfaces of the polysilicon conformal layer and the tungsten layer without intervening layers.
6 more elements
Dependencies are inferred from the claim text.