scholarly journals Positive non-linear capacitance: the origin of the steep subthreshold-slope in ferroelectric FETs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Md Nur K. Alam ◽  
P. Roussel ◽  
M. Heyns ◽  
J. Van Houdt
Keyword(s):  
Maxwell Equations ◽  
Experimental Validation ◽  
Negative Capacitance ◽  
Subthreshold Slope ◽  
Non Linear ◽  
Shape Curve ◽  
Steep Subthreshold Slope

Abstract We show that the non-linear positive capacitance (PC) of ferroelectrics (FE) can explain the steep subthreshold-slope (SS) observed in FE based MOSFETs and often attributed to the existence of a negative capacitance in FE capacitors. Physically attainable and unattainable regions of the S-shape curve used in the negative capacitance theory are investigated by self-consistently solving Landau-Khalatnikov and Maxwell equations and by experimental validation. Finally, the conditions for attaining a steep SS in FE based MOSFETs assuming only positive capacitances are discussed.

scholarly journals Ultrasensitive negative capacitance phototransistors

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Luqi Tu ◽  
Rongrong Cao ◽  
Xudong Wang ◽  
Yan Chen ◽  
Shuaiqin Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gate Dielectric ◽  
Negative Capacitance ◽  
Subthreshold Slope ◽  
Electrical And Optical Properties ◽  
Promising Candidate ◽  
Combined Action ◽  
Zirconium Oxide Film ◽  
Dark Currents ◽  
Steep Subthreshold Slope

AbstractSensitive photodetection is crucial for modern optoelectronic technology. Two-dimensional molybdenum disulfide (MoS2) with unique crystal structure, and extraordinary electrical and optical properties is a promising candidate for ultrasensitive photodetection. Previously reported methods to improve the performance of MoS2 photodetectors have focused on complex hybrid systems in which leakage paths and dark currents inevitably increase, thereby reducing the photodetectivity. Here, we report an ultrasensitive negative capacitance (NC) MoS2 phototransistor with a layer of ferroelectric hafnium zirconium oxide film in the gate dielectric stack. The prototype photodetectors demonstrate a hysteresis-free ultra-steep subthreshold slope of 17.64 mV/dec and ultrahigh photodetectivity of 4.75 × 1014 cm Hz1/2 W−1 at room temperature. The enhanced performance benefits from the combined action of the strong photogating effect induced by ferroelectric local electrostatic field and the voltage amplification based on ferroelectric NC effect. These results address the key challenges for MoS2 photodetectors and offer inspiration for the development of other optoelectronic devices.

Experimental Validation of Depolarization Field Produced Voltage Gains in Negative Capacitance Field-Effect Transistors

2019 ◽  
Vol 66 (10) ◽  
pp. 4419-4424 ◽  
Author(s):  
Jiuren Zhou ◽  
Genquan Han ◽  
Nuo Xu ◽  
Jing Li ◽  
Yue Peng ◽  
...  
Keyword(s):  
Field Effect ◽  
Experimental Validation ◽  
Field Effect Transistors ◽  
Negative Capacitance
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