Abstract:
Methods for fabricating integrated circuits are provided in various exemplary embodiments. In one embodiment, a method for fabricating an integrated circuit includes providing a germanium-based semiconductor substrate comprising a GeOx layer formed thereon having a first thickness, removing a portion of the GeOx layer by exposing the semiconductor substrate to a hydrogen-plasma dry etch so as to reduce the first thickness of the GeOx layer to a second thickness, and depositing a high-k material over the GeOx layer of the semiconductor substrate.
Abstract:
Devices with lightly-doped semiconductor channels (e.g., FinFETs) need mid-gap (˜4.6-4.7 eV) work-function layers, preferably with low resistivity and a wide process window, in the gate stack. Tantalum carbide (TaC) has a mid-gap work function that is insensitive to thickness. TaC can be deposited with good adhesion on high-k materials or on optional metal-nitride cap layers. TaC can also serve as the fill metal, or it can be used with other fills such as tungsten (W) or aluminum (Al). The TaC may be sputtered from a TaC target, deposited by ALD or CVD using TaCl4 and TMA, or produced by methane treatment of deposited Ta. Al may be added to tune the threshold voltage.
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.
Abstract:
An integrated circuit product includes an NMOS transistor having a gate structure that includes an NMOS gate insulation layer, a first NMOS metal layer positioned on the NMOS gate insulation layer, an NMOS metal silicide material positioned above the first NMOS metal layer, and a layer of a second metal material positioned above and in contact with the NMOS gate insulation layer, the first NMOS metal layer, and the NMOS metal silicide layer. The PMOS transistor has a gate structure that includes a PMOS gate insulation layer, a first PMOS metal layer positioned on the PMOS gate insulation layer, a PMOS metal silicide material positioned above the first PMOS metal layer, and a layer of the second metal material positioned above and in contact with the PMOS gate insulation layer, the first PMOS metal layer, and the PMOS metal silicide layer.
Abstract:
Methods for fabricating integrated circuits are provided in various exemplary embodiments. In one embodiment, a method for fabricating an integrated circuit includes providing a germanium-based semiconductor substrate comprising a GeOx layer formed thereon and exposing the semiconductor substrate to first and second atomic layer deposition (ALD) processes. The first ALD process includes exposing the semiconductor substrate to a first gaseous precursor comprising aluminum and exposing the semiconductor substrate to a second gaseous precursor comprising a first oxygen-containing precursor. The second ALD process includes exposing the semiconductor substrate to a first gaseous precursor comprising aluminum and exposing the semiconductor substrate to a second gaseous precursor comprising a second oxygen-containing precursor.
Abstract:
Metal-insulator-semiconductor (MIS) contacts for germanium and its alloys include insulator layers of oxygen-deficient metal oxide deposited by atomic layer deposition (ALD). The oxygen deficiency reduces the tunnel barrier resistance of the insulator layer while maintaining the layer's ability to prevent Fermi-level pinning at the metal/semiconductor interface. The oxygen deficiency is controlled by optimizing one or more ALD parameters such as shortened oxidant pulses, use of less-reactive oxidants such as water, heating the substrate during deposition, TMA “cleaning” of native oxide before deposition, and annealing after deposition. Secondary factors include reduced process-chamber pressure, cooled oxidant, and shortened pulses of the metal precursor.
Abstract:
Methods for fabricating integrated circuits are provided in various exemplary embodiments. In one embodiment, a method for fabricating an integrated circuit includes providing a germanium-based semiconductor substrate including a GeOx layer formed thereon having a first thickness, removing a portion of the GeOx layer by exposing the semiconductor substrate to a NF3/NH3 plasma dry etch so as to reduce the first thickness of the GeOx layer to a second thickness, and depositing a high-k material over the GeOx layer of the semiconductor substrate.
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.