Separation of interlayer resistance in multilayer MoS2 field-effect transistors

Abstract

We extracted the interlayer resistance between two layers in multilayer molybdenum disulfide (MoS2) field-effect transistors by confirming that contact resistances (Rcontact) measured using the four-probe measurements were similar, within ∼30%, to source/drain series resistances (Rsd) measured using the two-probe measurements. Rcontact values obtained from gated four-probe measurements exhibited gate voltage dependency. In the two-probe measurements, the Y-function method was applied to obtain the Rsd values. By comparing those two Rcontact (∼9.5 kΩ) and Rsd (∼12.3 kΩ) values in strong accumulation regime, we found the rationality that those two values had nearly the same properties, i.e., the Schottky barrier resistances and interlayer resistances. The Rsd values of devices with two-probe source/drain electrodes exhibited thickness dependency due to interlayer resistance changes. The interlayer resistance between two layers was also obtained as ∼2.0 Ω mm.

Li Intercalation Effects on Interface Resistances of High‐Speed and Low‐Power WSe2 Field‐Effect Transistors

“…We modeled the R DS as a resistance formed by the contact resistance (R contact ) on the gold electrode (Au)/top surface of the WSe 2 interface and additional interlayer resistances (R int ) at each multilayers WSe 2 interlayer interface (Figure 2e). We extracted the R DS and R channel using the Y-function method (Note S1 and Figure S3, Supporting Information) [35][36][37][38][39] (Figure 2f). The total resistance (R total ) is the sum of R DS and R channel .…”

“…[41] For µ, we used low field-effect mobility (µ 0 ) for minimizing effect of filed effect and contact resistance. [35][36][37] This µ 0 of pristine and after-Li intercalation were extracted from the slope of the fitted linear line in Figure S3a, Supporting Information, [35][36][37][38][39] and were 2 cm 2 V −1 s −1 and 108 cm 2 V −1 s −1 , respectively. After Li intercalation, the 2D sheet doping concentration increased from 4.64 × 10 12 cm −2 to 4.9 × 10 12 cm −2 , which indicates enhancement of carrier concentration by about 2.6 × 10 11 cm −2 due to electron transfer from intercalated Li ions.…”

Negligible hysteresis of molybdenum disulfide field-effect transistors through thermal annealing

“…The YFM was established by Ghibaudo for the evaluation of the MOSFET parameters, including low field mobility (μ 0 ) and contact resistance (R c ) [21]. The YFM has been proven to be a powerful method of evaluating the contact property of FETs with a single device, and is also often employed in the MoS 2 FETs [22][23][24]. The Y function is defined as…”

A General Approach to Probe Dynamic Operation and Carrier Mobility in Field‐Effect Transistors with Nonuniform Accumulation

“…This is the same as the well‐known form used in the traditional GFP technique for the linear regime . For comparison, the FET mobility µ FET is usually extracted by linear fitting with the | I D | – | V G | or – | V G | relations.…”