Modified transmission-line method for contact resistance extraction in organic field-effect transistors

Abstract

A modified transmission-line method (TLM) for organic transistors contact resistance extraction is proposed. It is shown that the issues of conventional TLM reside in the channel resistance scattering due to parameter variations. These difficulties are overcome in the modified TLM, in which the linear regression slope is directly controlled by the contact resistance rather than by the channel resistance as in conventional TLM. Much smaller transistor-to-transistor dispersion of contact resistance results in a more stable and more reliable extraction method. Moreover, an error study by simulation has been carried out, confirming the greater accuracy of the modified TLM.

Contact engineering in organic field-effect transistors

“…The group of R tot -L linear-regression lines often converge at a common point, called the convergence point (CP), which can be used to qualify the charge injection and charge transport [29]. When there is considerable scatter in m and V th (e.g., OFETs on bare SiO 2 with significant trapping effect), a modified TLM (M-TLM) is suggested to improve extraction accuracy [30,31]. Furthermore, to extract R c in a saturated regime, power TLM (P-TLM) should be applied by measuring the output characteristics (I d -V d ), which are derived from the dissipated power in the whole device regardless of the linear or saturated source-drain electric field [32].…”

Experimental and numerical analysis of channel-length-dependent electrical properties in bottom-gate, bottom-contact organic thin-film transistors with Schottky contact

“…For understanding the operation mechanism and evaluating properly the potential of semiconductor materials toward the performance improvement of the OTFTs, the reliable characterization methods for the parasitic resistance and real channel resistance have been demanded, and actually various extraction procedures of physical parameters on carrier transport in the OTFTs have been proposed [5][6][7][8][9]. Transfer (or transmission) line method (TLM) is the most widespread technique utilized by many research groups to separately estimate the parasitic resistance and the channel resistance [10][11][12][13][14][15][16], where data plots of the total resistance given by the ratio of the drain voltage and the drain current over the channel length have to reveal linear relationships for each gate voltage. The TLM method is based on the assumption that the parasitic resistance is independent of the channel length, and that the channel resistance is in proportion to it.…”

Nanostructure investigations of nonlinear differential conductance inNdNiO3thin films

“…This situation is not unprecedented, arising frequently in organic semiconductor device measurements [36], due to inhomogeneity of the organic channel. Based on our experiences in device fabrication with this material, inhomogeneities in both etched film properties and contact resistances are possible.…”