Investigation of Localized Charges on Linearity and Distortion Performance of Ferroelectric Dual Material Gate All Around TFETs

Authors Varun Mishra, Yogesh Kumar Verma, Santosh Kumar Gupta

Electronics and Communication Engineering Department, Motilal Nehru National Institute of Technology, Allahabad, India

Issue Volume 11, Year 2019, Number 4
Dates Received 28 March 2019; revised manuscript received 01 August 2019; published online 22 August 2019
Citation Varun Mishra, Yogesh Kumar Verma, Santosh Kumar Gupta#, J. Nano- Electron. Phys. 11 No 4, 04014 (2019)
PACS Number(s) 85.30.Mn, 73.43.Jn, 85.50. – n
Keywords Ferroelectric (7) , Localized charges, Negative capacitance, Third order intermodulation distortion, Zero crossover point.

Scaling down the MOSFETs below 20 nm implies several complications such as high OFF-state current due to thinning of gate oxide, drain induced barrier lowering, and other short channel effects (SCEs). In this aspect, tunnel-field-effect transistor (TFET) has emanated as the suitable contender to outshine the MOSFETs in nanoscale regime. Negative capacitance property of ferroelectric material is combined with the band-to-band tunneling mechanism of tunnel FET in order to enhance ON-state current of the device. Silicon doped hafnium oxide (Si:HfO2 is used as a ferroelectric layer (gate insulator). Lower permittivity and compatibility with the fabrication process flow of Si:HfO2, makes it a suitable ferroelectric material in contrary with perovskite materials. This work examines the impact of localized charges on electrical performance, linearity, and distortion parameters of ferroelectric-dual material-gate all around-tunnel field effect transistor (FE-DMGAA-TFET). The presence of oxide charges modifies the bias point of the device; therefore, its effect needs to be investigated in terms of figures of merit (FOM) of linearity and distortion. Localized oxide charge may be positive or negative depending on the trap energy level with respect to Fermi level. It is observed that OFF-state current deteriorates considerably for donor-localized charge from an order of 10–19 to 10–12 A. The non-linearity and distortion of the device decrease in the presence of negative localized charge. It has been analyzed through numerical calculations that due to donor-localized charges the subthreshold regime deteriorates significantly highlighting the requirement of an intensive analysis in this region for future niche market of electronics. However, the effect of acceptor-localized charges is marginal on the performance of the device, thus offering great potential to maintain its reliability.

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