International Business Machines Corporation

Douglas A Buchanan

Eduard Albert Cartier

Evgeni Petrovich Gousev

Cyril Cabral, Jr

Paul Michael Solomon

Fenton Read McFeely

Kathryn Wilder Guarini

An L Steegen

Huiling Shang

Victor Ku

Ricky S Amos

John J Yourkas

Arne Watson Ballantine

Douglas Duane Coolbaugh

Deborah A Neumayer

Harald F Okorn-Schmidt

Silicide is introduced into the gate region of a CMOS device through different process options for both conventional and replacement gate types processes. Placement of silicide in the gate itself, introduction of the silicide directly in contact with the gate dielectric, introduction of the silicide as a fill on top of a metal gate all ready in place, and introduction the silicide as a capping layer on polysilicon or on the existing metal gate, are presented. Silicide is used as an option to connect between PFET and NFET devices of a CMOS structure. The processes protect the metal gate while allowing for the source and drain silicide to be of a different silicide than the gate silicide. A semiconducting substrate is provided having a gate with a source and a drain region. A gate dielectric layer is deposited on the substrate, along with a metal gate layer. The metal gate layer is then capped with a silicide formed on top of the gate, and conventional formation of the device then proceeds. A second silicide may be employed within the gate. A replacement gate is made from two different metals (dual metal gate replacement) prior to capping with a silicide.

Process options of forming silicided metal gates for advanced CMOS devices

A precursor source mixture useful for CVD or ALD of a film comprising: at least one precursor composed of an element selected from the group consisting of Li, Na, K, Rb, Cs, Fr, Be, Mg, Ti, Zr, Hf, Sc, Y, La, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, P, Sb and Bi, to which is bound at least one ligand selected from the group consisting of hydride, alkyl, alkenyl, cycloalkenyl, aryl, alkyne, carbonyl, amido, imido, hydrazido, phosphido, nitrosyl, nitryl, nitrate, nitrile, halide, azide, alkoxy, siloxy, silyl, and halogenated, sulfonated or silyated derivatives thereof, which is dissolved, emulsified or suspended in an inert liquid selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, ethers, aldehydes, ketones, acids, phenols, esters, amines, alkylnitrile, halogenated hydrocarbons, silyated hydrocarbons, thioethers, amines, cyanates, isocyanates, thiocyanates, silicone oils, nitroalkyl, alkylnitrate, and mixtures thereof. The precursor source mixture may be a solution, emulsion or suspension and may consist of a mixture of solid, liquid and gas phases which are distributed throughout the mixture.

Precursor source mixtures

A process for passivating the semiconductor-dielectric interface of a MOS structure to reduce the interface state density to a very low level. A particular example is a MOSFET having a tungsten electrode that in the past has prevented passivation of the underlying semiconductor-dielectric interface to an extent sufficient to reduce the interface state density to less than 5&times;10 /cm &minus;eV. Though substantially impervious to molecular hydrogen, thin tungsten layers are shown to be pervious to atomic hydrogen, enabling atomic hydrogen to be diffused through a tungsten electrode into an underlying semiconductor-dielectric interface. Three general approaches are encompassed: forming an aluminum-tungsten electrode stack in the presence of hydrogen so as to store atomic hydrogen between the tungsten and aluminum layers, followed by an anneal to cause the atomic hydrogen to diffuse through the tungsten layer and into the interface; subjecting a tungsten electrode to hydrogen plasma, during which atomic hydrogen diffuses through the electrode and into the semiconductor-dielectric interface; and implanting atomic hydrogen into tungsten electrode, followed by an anneal to cause the atomic hydrogen to diffuse through the electrode and into the semiconductor-dielectric interface.

Process for passivating the semiconductor-dielectric interface of a MOS device and MOS device formed thereby

Methods of forming front-end-of the line (FEOL) capacitors such as polysilicon-polysilicon capacitors and metal-insulator-silicon capacitors are provided that are capable of incorporating a high-dielectric constant (k of greater than about 8) into the capacitor structure. The inventive methods provide high capacitance/area devices with low series resistance of the top and bottom electrodes for high frequency responses. The inventive methods provide a significant reduction in chip size, especially in analog and mixed-signal applications where large areas of capacitance are used.

High-dielectric constant insulators for FEOL capacitors

A MOS structure processed to have a semiconductor-dielectric interface that is passivated to reduce the interface state density. An example is a MOSFET having a gate dielectric on which an electrode is present that is substantially impervious to molecular hydrogen, but sufficiently thin to be pervious to atomic hydrogen, enabling atomic hydrogen to be diffused therethrough into an underlying semiconductor-dielectric interface. Atomic hydrogen diffusion can be achieved by subjecting such an electrode to hydrogen plasma, forming the electrode of an aluminum-tungsten alloy in the presence of hydrogen, and implanting atomic hydrogen into the electrode. The latter two techniques are each followed by an anneal to cause the atomic hydrogen to diffuse through the electrode and into the semiconductor-dielectric interface.

MOS device having a passivated semiconductor-dielectric interface

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Winnipeg, Canada

Douglas A Buchanan