Abstract: A new, effective and cost-efficient method of introducing Fluorine into Hf-based dielectric gate stacks of planar or multi-gate devices (MuGFET), resulting in a significant improvement in both Negative and Positive Bias Temperature Instabilities (NBTI and PBTI) is provided. The new method uses an SF6 based metal gate etch chemistry for the introduction of Fluorine, which after a thermal budget within the standard process flow, results in excellent F passivation of the interfaces. A key advantage of the method is that it uses the metal gate etch for F introduction, requiring no extra implantations or treatments. In addition to the significant BTI improvement with the novel method, a better Vth control and increased drive current on MuGFET devices is achieved.

Abstract: A method for the selective removal of a high-k layer such as HfO2 over silicon or silicon dioxide is provided. More specifically, a method for etching high-k selectively over silicon and silicon dioxide and a plasma composition for performing the selective etch process is provided. Using a BCl3 plasma with well defined concentrations of nitrogen makes it possible to etch high-k with at a reasonable etch rate while silicon and silicon dioxide have an etch rate of almost zero. The BCl3 comprising plasmas have preferred additions of 10 up to 13% nitrogen. Adding a well defined concentration of nitrogen to the BCl3/N2 plasma gives the unexpected deposition of a Boron-Nitrogen (BxNy) comprising film onto the silicon and silicon dioxide which is not deposited onto the high-k material. Due to the deposition of the Boron-Nitrogen (BxNy) comprising film, the etch rate of silicon and silicon dioxide is dropped down to zero.

Abstract: A method is disclosed for the selective removal of rare earth based high-k materials such as rare earth scandate high-k materials (e.g. DyScO3) over silicon or silicon dioxide. As an example Dy and Sc comprising high-k materials are used as a high-k material in gate stacks of a semiconductor device. The selective removal and etch of this high-k material is very difficult since Dy and Sc (and their oxides) are difficult to etch. The etching could however be easily stopped on them. For patterning of the metal gates comprising TiN and TaN on top of rare earth based high-k layer a chlorine-containing gases (Cl2 and BCl3) can be used since titanium ant tantalum chlorides are volatile and reasonable selectivity to other material present on the wafer (Si, SiO2) can be obtained. The Dy and Sc chlorides are not volatile, but they are water soluble.

Abstract: A new, effective and cost-efficient method of introducing Fluorine into Hf-based dielectric gate stacks of planar or multi-gate devices (MuGFET), resulting in a significant improvement in both Negative and Positive Bias Temperature Instabilities (NBTI and PBTI) is provided. The new method uses an SF6 based metal gate etch chemistry for the introduction of Fluorine, which after a thermal budget within the standard process flow, results in excellent F passivation of the interfaces. A key advantage of the method is that it uses the metal gate etch for F introduction, requiring no extra implantations or treatments. In addition to the significant BTI improvement with the novel method, a better Vth control and increased drive current on MuGFET devices is achieved.

Abstract: A method is provided for the patterning of a stack comprising elements that do not form volatile compounds during conventional reactive ion etching. More specifically the element(s) are Lanthanide elements such as Ytterbium (Yb) and the patterning preferably relates to the dry etching of silicon and/or germanium comprising structures (e.g. gates) doped with a Lanthanide e.g. Ytterbium (Yb doped gates). In case the silicon and/or germanium comprising structure is a gate electrode the silicon and/or germanium is doped with a Lanthanide (e.g. Yb) for modeling the work function of a gate electrode.

Abstract: A method is provided for the patterning of a stack comprising elements that do not form volatile compounds during conventional reactive ion etching. More specifically the element(s) are Lanthanide elements such as Ytterbium (Yb) and the patterning preferably relates to the dry etching of silicon and/or germanium comprising structures (e.g. gates) doped with a Lanthanide e.g. Ytterbium (Yb doped gates). In case the silicon and/or germanium comprising structure is a gate electrode the silicon and/or germanium is doped with a Lanthanide (e.g. Yb) for modeling the work function of a gate electrode.

Abstract: A method is disclosed for the selective removal of rare earth based high-k materials such as rare earth scandate high-k materials (e.g. DyScO3) over silicon or silicon dioxide. As an example Dy and Sc comprising high-k materials are used as a high-k material in gate stacks of a semiconductor device. The selective removal and etch of this high-k material is very difficult since Dy and Sc (and their oxides) are difficult to etch. The etching could however be easily stopped on them. For patterning of the metal gates comprising TiN and TaN on top of rare earth based high-k layer a chlorine-containing gases (Cl2 and BCl3) can be used since titanium ant tantalum chlorides are volatile and reasonable selectivity to other material present on the wafer (Si, SiO2) can be obtained. The Dy and Sc chlorides are not volatile, but they are water soluble.

Abstract: A method for the selective removal of a high-k layer such as HfO2 over silicon or silicon dioxide is provided. More specifically, a method for etching high-k selectively over silicon and silicon dioxide and a plasma composition for performing the selective etch process is provided. Using a BCl3 plasma with well defined concentrations of nitrogen makes it possible to etch high-k with at a reasonable etch rate while silicon and silicon dioxide have an etch rate of almost zero. The BCl3 comprising plasmas have preferred additions of 10 up to 13% nitrogen. Adding a well defined concentration of nitrogen to the BCl3/N2 plasma gives the unexpected deposition of a Boron-Nitrogen (BxNy) comprising film onto the silicon and silicon dioxide which is not deposited onto the high-k material. Due to the deposition of the Boron-Nitrogen (BxNy) comprising film, the etch rate of silicon and silicon dioxide is dropped down to zero.

Abstract: A plasma composition and its use in a method for the dry etching of a stack of at least one material chemically too reactive towards the use of a Cl-based plasma are provided. Small amounts of nitrogen (5% up to 10%) can be added to a BCl3 comprising plasma and used in an anisotropical dry etching method whereby a passivation film is deposited onto the vertical sidewalls of stack etched for protecting the vertical sidewalls from lateral attack such that straight profiles can be obtained.