Texas Instruments Corporation

Manfred Ramin

Michael Francis Pas

Husam N Alshareef

Puneet Kohli

Mark R Visokay

Angelo Pinto

Weize W Xiong

Craig Henry Huffman

Semiconductor devices and fabrication methods are provided, in which fully silicided gates are provided. A lanthanide series metal is implanted into the gate electrode layer prior to silicidation and diffuses into the gate dielectric during an activation anneal. This process and resultant structure provides adjustment of the gate electrode work function, thereby tuning the threshold voltage of the resulting transistor.

Work function adjustment with the implant of lanthanides

A transistor includes a semiconductor substrate includes having a gate hardmask over the gate electrode layer during the formation of transistor source/drain regions. An independent work function adjustment process implants Group IIIa series dopants into a gate polysilicon layer of a PMOS transistor and implants lanthanide series dopants into a gate polysilicon layer of a NMOS transistor.

Integration scheme for dual work function metal gates

A method for manufacturing a semiconductor device includes forming a gate electrode over a gate dielectric. The gate dielectric is formed by forming a lanthanide metal layer over a nitrided silicon oxide layer, and then performing an anneal to inter-diffuse atoms to form a lanthanide silicon oxynitride layer. A gate electrode layer may be deposited before or after the anneal. In an embodiment, the gate electrode layer includes a non-lanthanide metal layer, a barrier layer formed over the non-lanthanide metal layer, and a polysilicon layer formed over the barrier layer. Hafnium atoms may optionally be implanted into the nitrided silicon oxide layer.

Method of forming a high-k gate dielectric layer

A chemical mechanical polishing (CMP) stop layer is implemented in a semiconductor fabrication process. The CMP stop layer, among other things, mitigates erosion of sidewall spacers during semiconductor fabrication and adverse effects associated therewith.

Sacrificial CMP etch stop layer

A method for semiconductor processing provides a DSB semiconductor body having a first crystal orientation, a second crystal orientation, and a border region disposed between the first and second crystal orientations. The border region further has a defect associated with an interface of the first crystal orientation and second the second crystal orientation, wherein the defect generally extends a distance into the semiconductor body from a surface of the body. A sacrificial portion of the semiconductor body is removed from the surface thereof, wherein removing the sacrificial portion at least partially removes the defect. The sacrificial portion can be defined by oxidizing the surface at low temperature, wherein the oxidation at least partially consumes the defect. The sacrificial portion can also be removed by CMP. An STI feature may be further formed over the defect after removal of the sacrificial portion, therein consuming any remaining defect.

Method to eliminate re-crystallization border defects generated during solid phase epitaxy of a DSB substrate

Semiconductor devices and fabrication methods are provided, in which fully silicided transistor gates are provided for MOS transistors. A lanthanide series metal is implanted into the gate electrode layer prior to silicidation and diffuses into the gate dielectric during an activation anneal. This process and resultant structure provides adjustment of the gate electrode work function, thereby tuning the threshold voltage of the resulting transistor.

Semiconductor devices and fabrication methods are provided, in which metal transistor gates are provided for MOS transistors. Metal nitride is formed above a gate dielectric. A lanthaide series metal is implanted into the metal screen layer above the gate dielectric. The lanthaide metal is contained in the screen layer or at the interface between the screen metal layer and the gate dielectric. This process provides adjustment of the gate electrode work function, thereby tuning the threshold voltage of the resulting PMOS or NMOS transistors.

Lanthanide series metal implant to control work function of metal gate electrodes

A method for manufacturing a semiconductor device. The method comprises forming a dielectric layer. Forming the dielectric layer includes depositing a silicon oxide layer on a semiconductor substrate, nitridating the silicon oxide layer to form a nitrided silicon oxide layer and incorporating lanthanide atoms into the nitrided silicon oxide layer to form a lanthanide silicon oxynitride layer.

A simple and cost effective method of forming a fully silicided (FUSI) gate of a MOS transistor is disclosed. In one example, the method comprises forming a nitride hardmask overlying a polysilicon gate, forming an S/D silicide in source/drain regions of the transistor, oxidizing a portion of the S/D silicide to form an oxide barrier overlying the S/D silicide in the source/drain regions, removing the nitride hardmask from the polysilicon gate, and forming a gate silicide such as by deposition of a gate silicide metal over the polysilicon gate and the oxide barrier in the source/drain regions to form a fully silicided (FUSI) gate in the transistor. Thus, the oxide barrier protects the source/drain regions from additional silicide formation by the gate silicide metal formed thereafter. The method may further comprise selectively removing the oxide barrier in the source/drain regions after forming the fully silicided (FUSI) gate.

Formation of fully silicided gate with oxide barrier on the source/drain silicide regions

A method of fabricating a dual metal gate structures in a semiconductor device, the method comprising forming a gate dielectric layer above a semiconductor body, forming a work function adjusting layer on the dielectric gate layer in the PMOS region, depositing a tungsten germanium gate electrode layer above the work function adjusting material in the PMOS region, depositing a tungsten germanium gate electrode layer above the gate dielectric in the NMOS region annealing the semiconductor device, depositing a metal nitride barrier layer on the tungsten germanium layer, depositing a polysilicon layer over the metal nitride, patterning the polysilicon layer, the metal nitride layer, the tungsten germanium layer, work function adjusting layer and the gate dielectric layer to form a gate structure, and forming a source/drain on opposite sides of the gate structure.

Doped WGe to form dual metal gates

In one aspect, the invention provides a method of fabricating a semiconductive devicethat comprises forming a raised layer [] adjacent a gate [] and over a source/drain [], depositing a silicidation layer [] over the gate [] and the raised layer [], and moving at least a portion of the silicidation layer [] into the source/drain [] through the raised layer [

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Austin, TX, United States of America

Manfred Ramin