Novel Band-Edge Work Function Performance Modulation via NPT with PMOS ^1st /NMOS ^1st Laminated Stack for PMOS Low Power Target

In this paper, the band-edge work function performance is systematically investigated and modulated via novel nitrogen plasma treatment (NPT) with the advanced PMOS ^1st (TiN/TiN/TiAlC) and NMOS ^1st (TiN/TiN) laminated stacks for the fabricated PMOS capacitors. The basic multi-V _T performance is strongly modulated by controlling NPT process. 1) Flatband voltage (V _FB ) shifts towards band edge are obtained as +120 mV (undiluted), +430 mV (diluted) for PMOS ^1st and +80 mV (undiluted), +210 mV (diluted) for NMOS ^1st . 2) By manipulating the NPT process from undiluted and diluted case, it can provide significant high band-edge effective work function ranging from 4.89 eV (undiluted) to 5.21 eV (diluted) for PMOS ^1st and 5.22 eV (undiluted) to 5.35 eV (diluted) for NMOS ^1st laminated stack, respectively. 3) NPT diluted with hydrogen is observed to maintain ultralow bulk trap density (1.11 × 10 ¹¹ cm ⁻² for PMOS ^1st and nearly zero for NMOS ^1st ) and interface trap density (3.34 × 10 ¹¹ eV ⁻¹ cm ⁻² for PMOS ^1st and 6.45 × 10 ¹¹ eV ⁻¹ cm ⁻² for NMOS ^1st ). The significant band-edge work function modulation and very low bulk and interface trap density demonstrate the novel NPT with PMOS ^1st /NMOS ^1st laminated stack is very promising to achieve the target of PMOS low-power application in the further technology node.