Two-dimensional (2D) transition metal dichalcogenide semiconductor field-effect transistors: the interface trap density extraction and compact model

Abstract

A surface potential-based low-field drain current compact model is presented for twodimensional (2D) transition metal dichalcogenide (TMD) semiconductor field-effect transistors that takes into account the effect of interface trap states on device current-voltage (I ds -V gs ) characteristics and transconductance g m . The presence of interface trap states detrimentally affects device I ds -V gs performance. Minimal work exists on the extraction of trap states (cm −2 eV −1 ) of MoS 2 /high-K dielectric/metal-gate stacks. Additionally, there is a lack of compact models for 2D TMD MOSFETs that can take into account the effect of trap states on device I ds -V gs performance. This study presents a method to extract the interface trap distribution of MoS 2 MOSFETs using a compact model. Presented as part of the model is a surface potential/ interface trap charge self-consistent calculation procedure and a drain current expression that does not need numerical integration. The model is tested against reported experimental I ds -V gs data, and excellent agreement is found between the experiment and the model.

Impact and Origin of Interface States in MOS Capacitor with Monolayer MoS2 and HfO2 High-k Dielectric

“…Mid-gap D it of ~1 × 10 12  cm −2  eV −1 was also reported for the CVD-grown monolayer-MoS 2 /AlO x /HfO 2 /Ti/Au top gate stack using capacitance and AC conductance methods33. However, very limited results on MoS 2 -HfO 2 interface have been reported34. Here, due to a much better uniformity of the MoS 2 film as compared to CVD grown MoS 2 17, we expect the quality of the dielectric and thereby D it in top-gate device with MoS 2 channel should be comparable to that of high- k device with MoS 2 prepared by mechanical exfoliation.…”

Metal oxide-graphene field-effect transistor: interface trap density extraction model

“…It must be mentioned part of this work is based on our earlier work on MoS 2 transistor [14] as briefly mentioned earlier. However, in that work the interface trap density of MoS 2 transistor was extrated by simply fitting the Q it parameter in the device’s drain current ( I ds ) model to fit experimental device’s I ds with the calculated one from the model.…”

“…However, in this work, instead of fitting Q it in a drain current expression, a thorough analytical framework has been developed, based on fundamental MOGFET device physics, to extract important experimental parameters including Q it , C it and φ s data from experimental C tot – V gs data as highlighted in the section “Experimental φ s , C it , and Q it extraction”. Using these experimental parameters as a reference and the framework developed earlier [14–15] an analytical framework was presented to extract the interface trap distribution of MOGFET devices.…”

“…D it distribution extraction criteria are based on our earlier work on MoS 2 MOSFET [14], and are highlighted in Fig. 2.…”

“…8 using Q it_calc and φ s_calc as input variables. The self-consistent C it_calc –φ s_calc calculation procedure is based on our earlier works on MOSFET interface trap drain current modeling [14–15]. The procedure is highlighted in Fig.…”