Effect of Hydrogen Annealing on Contact Resistance Reduction of Metal–Interlayer–n-Germanium Source/Drain Structure

Schottky Barrier Height Engineering for Electrical Contacts of Multilayered MoS2 Transistors with Reduction of Metal-Induced Gap States

“…Mechanism of SBH Control: Fermi-Level Unpinning by MIGS Reduction. The SBH control by insertion of the interlayer can be explained by three mechanisms: (1) Fermilevel unpinning by the MIGS reduction, [23][24][25][26][27][28][29][30][31][32]35,36 (2) Fermilevel unpinning by the metal/semiconductor interface passivation, 27,28,44 and (3) interface dipole formation. 23,26,33,34,36 First, the two Fermi-level unpinning effects and the interface dipole effect can be separated from the SBH vs contact metal work function plot as shown in Figure 6a.…”

“…The SBH control by insertion of the interlayer can be explained by three mechanisms: (1) Fermi-level unpinning by the MIGS reduction, − ,, (2) Fermi-level unpinning by the metal/semiconductor interface passivation, ,, and (3) interface dipole formation. ,,,, First, the two Fermi-level unpinning effects and the interface dipole effect can be separated from the SBH vs contact metal work function plot as shown in Figure a. In the plot, the intersection point between the ideal line with S = 1 and the experimentally obtained MS line with S = 0.02 is a branch point that does not change as the pinning factor changes.…”

“…These MIGS have been identified as the main cause of the FLP in conventional semiconductor materials. Therefore, a metal–interlayer–semiconductor (MIS) structure has been developed to alleviate the FLP and reduce the electron SBH by reducing the MIGS in Si, , Ge, − and III–V. − Ultrathin interlayers such as TiO 2 − ,,, and ZnO − ,, which exhibit a small conduction band offset (CBO) to semiconductor materials are inserted between the metal contact and the semiconductor as the Fermi-level unpinning layer that minimizes the increase in the interlayer resistance. Several researchers have previously developed the MIS structure for the MoS 2 to control the electron SBH of its electrical contacts by using Ta 2 O 5 , TiO 2 , − MgO, and h -BN , interlayers.…”

“…In this work, the SBH controllability is improved by using an MIS structure on multilayered MoS 2 FETs, and its SBH controlling mechanism is systematically investigated by analyzing three possible mechanisms: (1) Fermi-level unpinning by the MIGS reduction, − ,, (2) Fermi-level unpinning by the metal/semiconductor interface passivation, ,, and (3) interface dipole formation. ,,,, Four metals with various work-function values, titanium (Ti), copper (Cu), gold (Au), and platinum (Pt), are adopted as contact metals with an ultrathin titanium dioxide (TiO 2 ) interlayer, and the transfer characteristics of multilayered MoS 2 FETs and SBH of their S/D contacts are analyzed to demonstrate the SBH-controlling effect. The mechanism of the SBH control is investigated by comparing each of the three possible mechanisms.…”

Impact of Random Dopant Fluctuation on n-Type Ge Junctionless FinFETs With Metal–Interlayer–Semiconductor Source/Drain Contact Structure

“…2(a). The high density of metal-induced gap states (MIGS) between the metal and the semiconductor stimulates the FLP, which in turn triggers high Schottky barrier, occurring as a very large hole off-state current [11], [15], [16]. For this reason, the MS structure critically disturbs the n-type Ge JLFETs operating in enhancement-mode.…”