Abstract: Methods are provided for fabricating integrated circuits having controlled threshold voltages. In accordance with one embodiment a method includes forming a gate dielectric overlying an N-doped silicon substrate and depositing a layer of titanium nitride and a layer of tantalum nitride overlying the gate dielectric. A sub-monolayer of tantalum oxide is deposited overlying the layer of tantalum nitride by a process of atomic layer deposition, and oxygen is diffused from the tantalum oxide through the tantalum nitride and titanium nitride.

Abstract: Methods are provided for fabricating integrated circuits having controlled threshold voltages. In accordance with one embodiment a method includes forming a gate dielectric overlying an N-doped silicon substrate and depositing a layer of titanium nitride and a layer of tantalum nitride overlying the gate dielectric. A sub-monolayer of tantalum oxide is deposited overlying the layer of tantalum nitride by a process of atomic layer deposition, and oxygen is diffused from the tantalum oxide through the tantalum nitride and titanium nitride.

Abstract: During the formation of sophisticated gate electrode structures, a replacement gate approach may be applied in which plasma assisted etch processes may be avoided. To this end, one of the gate electrode structures may receive an intermediate etch stop liner, which may allow the replacement of the placeholder material and the adjustment of the work function in a later manufacturing stage. The intermediate etch stop liner may not negatively affect the gate patterning sequence.

Abstract: In a replacement gate approach, the sacrificial gate material is exposed on the basis of enhanced process uniformity, for instance during a wet chemical etch step or a CMP process, by forming a modified portion in the interlayer dielectric material by ion implantation. Consequently, the damaged portion may be removed with an increased removal rate while avoiding the creation of polymer contaminants when applying an etch process or avoiding over-polish time when applying a CMP process.

Abstract: When forming sophisticated high-k metal gate electrode structures on the basis of a replacement gate approach, the fill conditions upon filling in the highly conductive electrode metal, such as aluminum, may be enhanced by removing an upper portion of the final work function metal, for instance a titanium nitride material in P-channel transistors. In some illustrative embodiments, the selective removal of the metal-containing electrode material in an upper portion of the gate opening may be accomplished without unduly increasing overall process complexity.

Abstract: Generally, the subject matter disclosed herein relates to modern sophisticated semiconductor devices and methods for forming the same, wherein a reduced threshold voltage (Vt) may be achieved in HK/MG transistor elements that are manufactured based on replacement gate electrode integrations. One illustrative method disclosed herein includes forming a first metal gate electrode material layer above a gate dielectric material layer having a dielectric constant of approximately 10 or greater. The method further includes exposing the first metal gate electrode material layer to an oxygen diffusion process, forming a second metal gate electrode material layer above the first metal gate electrode material layer, and adjusting an oxygen concentration gradient and a nitrogen concentration gradient in at least the first metal gate electrode material layer and the gate dielectric material layer.

Abstract: During a manufacturing sequence for forming a sophisticated high-k metal gate structure, a cover layer, such as a silicon layer, may be deposited on a metal cap layer in an in situ process in order to enhance integrity of the metal cap layer. The cover layer may provide superior integrity during the further processing, for instance in view of performing wet chemical cleaning processes and the subsequent deposition of a silicon gate material.

Abstract: In a replacement gate approach, the sacrificial gate material is exposed on the basis of enhanced process uniformity, for instance during a wet chemical etch step or a CMP process, by forming a modified portion in the interlayer dielectric material by ion implantation. Consequently, the damaged portion may be removed with an increased removal rate while avoiding the creation of polymer contaminants when applying an etch process or avoiding over-polish time when applying a CMP process.

Abstract: In a replacement gate approach in sophisticated semiconductor devices, a tantalum nitride etch stop material may be efficiently removed on the basis of a wet chemical etch recipe using ammonium hydroxide. Consequently, a further work function adjusting material may be formed with superior uniformity, while the efficiency of the subsequent adjusting of the work function may also be increased. Thus, superior uniformity, i.e., less pronounced transistor variability, may be accomplished on the basis of a replacement gate approach in which the work function of the gate electrodes of P-channel transistors and N-channel transistors is adjusted after completing the basic transistor configuration.

Abstract: In a replacement gate approach in sophisticated semiconductor devices, the placeholder material of gate electrode structures of different type are separately removed. Furthermore, electrode metal may be selectively formed in the resulting gate opening, thereby providing superior process conditions in adjusting a respective work function of gate electrode structures of different type. In one illustrative embodiment, the separate forming of gate openings in gate electrode structures of different type may be based on a mask material that is provided in a gate layer stack.

Abstract: When forming sophisticated high-k metal gate electrode structures, for instance on the basis of a replacement gate approach, superior interface characteristics may be obtained on the basis of using a thermally grown base material, wherein the electrically effective thickness may be reduced on the basis of a low temperature anneal process. Consequently, the superior interface characteristics of a thermally grown base material may be provided without requiring high temperature anneal processes, as are typically applied in conventional strategies using a very thin oxide layer formed on the basis of a wet oxidation chemistry.

Abstract: In a replacement gate approach, the sacrificial gate material is exposed on the basis of enhanced process uniformity, for instance during a wet chemical etch step or a CMP process, by forming a modified portion in the interlayer dielectric material by ion implantation. Consequently, the damaged portion may be removed with an increased removal rate while avoiding the creation of polymer contaminants when applying an etch process or avoiding over-polish time when applying a CMP process.

Abstract: In a replacement gate approach in sophisticated semiconductor devices, the place-holder material of gate electrode structures of different type are separately removed. Furthermore, electrode metal may be selectively formed in the resulting gate opening, thereby providing superior process conditions in adjusting a respective work function of gate electrode structures of different type. In one illustrative embodiment, the separate forming of gate openings in gate electrode structures of different type may be based on a mask material that is provided in a gate layer stack.

Abstract: By locally heating isolation trenches with different annealing conditions, a different magnitude of intrinsic stress may be obtained in different isolation trenches. In some illustrative embodiments, the different anneal temperature may be achieved on the basis of an appropriate mask layer, which may provide a patterned optical response for a lamp-based or laser-based anneal process. Consequently, the intrinsic stress of isolation trenches may be specifically adapted to the requirements of circuit elements, such as N-channel transistors and P-channel transistors.

Abstract: In a replacement gate approach, the semiconductor material or at least a significant portion thereof in a non-transistor structure, such as a precision resistor, an electronic fuse and the like, may be preserved upon replacing the semiconductor material in the gate electrode structures. To this end, an appropriate dielectric material may be provided at least prior to the removal of the semiconductor material in the gate electrode structures, without requiring significant modifications of established replacement gate approaches.

Abstract: In a replacement gate approach, a superior cross-sectional shape of the gate opening may be achieved by performing a material erosion process in an intermediate state of removing the placeholder material. Consequently, the remaining portion of the placeholder material may efficiently protect the underlying sensitive materials, such as a high-k dielectric material, when performing the corner rounding process sequence.

Abstract: In a replacement gate approach, the oxygen contents of a cap material may be increased, thereby providing more stable characteristics of the cap material itself and of the high-k dielectric material. Consequently, upon providing a work function adjusting metal species at a very advanced manufacturing stage, corresponding additional treatments may be reduced in number or may even be completely avoided, while at the same time threshold voltage variations may be reduced.

Abstract: In a replacement gate approach in sophisticated semiconductor devices, the place-holder material of gate electrode structures of different type are separately removed. Furthermore, electrode metal may be selectively formed in the resulting gate opening, thereby providing superior process conditions in adjusting a respective work function of gate electrode structures of different type. In one illustrative embodiment, the separate forming of gate openings in gate electrode structures of different type may be based on a mask material that is provided in a gate layer stack.

Abstract: In a replacement gate approach, a superior cross-sectional shape of the gate opening may be achieved by performing a material erosion process in an intermediate state of removing the placeholder material. Consequently, the remaining portion of the placeholder material may efficiently protect the underlying sensitive materials, such as a high-k dielectric material, when performing the corner rounding process sequence.

Abstract: In a replacement gate approach, a superior cross-sectional shape of the gate opening may be achieved by performing a material erosion process in an intermediate state of removing the placeholder material. Consequently, the remaining portion of the placeholder material may efficiently protect the underlying sensitive materials, such as a high-k dielectric material, when performing the corner rounding process sequence.