Abstract:
A gate structure of a semiconductor device having a NFET and a PFET, includes a lower layer of a hafnium-based dielectric over the gates of the NFET and PFET, and an upper layer of a lanthanide dielectric. The dielectrics are annealed to mix them above the NFET resulting in a lowered work function, and corresponding threshold voltage reduction. An annealed, relatively thick titanium nitride cap over the mixed dielectric above the NFET gate also lowers the work function and threshold voltage. Above the TiN cap and the hafnium-based dielectric over the PFET gate, is another layer of titanium nitride that has not been annealed. A conducting layer of tungsten covers the structure.
Abstract:
One illustrative method disclosed herein includes forming replacement gate structures for an NMOS transistor and a PMOS transistor by forming gate insulation layers and a first metal layer for the devices from the same materials and selectively forming a metal-silicide material layer only on the first metal layer for the NMOS device but not on the PMOS device. One example of a novel integrated circuit product disclosed herein includes an NMOS device and a PMOS device wherein the gate insulation layers and the first metal layer of the gate structures of the devices are made of the same material, the gate structure of the NMOS device includes a metal silicide material positioned on the first metal layer of the NMOS device, and a second metal layer that is positioned on the metal silicide material for the NMOS device and on the first metal layer for the PMOS device.
Abstract:
One illustrative method disclosed herein includes forming gate insulation layers and a first metal layer for NMOS and PMOS devices from the same material, selectively forming a first metal layer only for the PMOS device, and forming different shaped metal silicide regions within the NMOS and PMOS gate cavities. A novel integrated circuit product disclosed herein includes an NMOS transistor with an NMOS gate insulation layer, an NMOS metal silicide having a generally rectangular cross-sectional configuration and an NMOS metal layer positioned on the NMOS metal silicide region. The product also includes a PMOS transistor with the same gate insulation material, a first PMOS metal and a PMOS metal silicide region, wherein the NMOS and PMOS metal silicide regions are comprised of the same metal silicide.
Abstract:
ALD of HfxAlyCz films using hafnium chloride (HfCl4) and Trimethylaluminum (TMA) precursors can be combined with post-deposition anneal processes and ALD liners to control the device characteristics in high-k metal-gate devices. Variation of the HfCl4 pulse time allows for control of the Al % incorporation in the HfxAlyCz film in the range of 10-13%. Combinatorial process tools can be employed for rapid electrical and materials characterization of various materials stacks. The effective work function (EWF) in metal oxide semiconductor capacitor (MOSCAP) devices with the HfxAlyCz work function layer coupled with ALD deposited HfO2 high-k gate dielectric layers was quantified to be mid-gap at ˜4.6 eV. Thus, HfxAlyCz is a promising metal gate work function material allowing for the tuning of device threshold voltages (Vth) for anticipated multi-Vth integrated circuit (IC) devices.
Abstract:
A method of fabricating a replacement gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over the area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; performing a first rapid thermal anneal; removing the sacrificial layer; and depositing a metal layer of low resistivity metal for gap fill.
Abstract:
A method of fabricating a replacement gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over the area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; performing a first rapid thermal anneal; removing the sacrificial layer; and depositing a metal layer of low resistivity metal for gap fill.
Abstract:
An improved field effect transistor and method of fabrication are disclosed. A barrier layer stack is formed in the base and sidewalls of a gate cavity. The barrier layer stack has a first metal layer and a second metal layer. A gate electrode metal is deposited in the cavity. The barrier layer stack is thinned or removed on the sidewalls of the gate cavity, to more precisely control the voltage threshold of the field effect transistor.
Abstract:
One method and device disclosed includes, among other things, forming a recessed sacrificial gate electrode having a recessed upper surface, performing at least one second etching process to define recessed sidewall spacers positioned adjacent the recessed sacrificial gate electrode, forming a plurality of sidewall spacers within a gate opening above the recessed sidewall spacers, wherein one of the spacers comprises a low-k insulating material that is positioned laterally between two other spacers and a gate cap layer, removing the recessed sacrificial gate electrode and forming a replacement gate structure in its place.
Abstract:
A method of fabricating a replacement gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over the area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; performing a first rapid thermal anneal; removing the sacrificial layer; and depositing a metal layer of low resistivity metal for gap fill.
Abstract:
One method for forming replacement gate structures for NMOS and PMOS transistors includes performing an etching process to remove a sacrificial gate structure for the NMOS and PMOS transistors to thereby define NMOS and PMOS gate cavities, depositing a gate insulation layer in the gate cavities, depositing a first metal layer on the gate insulation layer in the gate cavities, performing at least one process operation to form (1) an NMOS metal silicide material above the first metal layer within the NMOS gate cavity, the NMOS metal silicide material having a first amount of atomic silicon, and (2) a PMOS metal silicide material above the first metal layer within the PMOS gate cavity, the PMOS metal silicide material having a second amount of atomic silicon, and wherein the first and second amounts of atomic silicon are different, and forming gate cap layers within the NMOS and PMOS gate cavities.