Nguyen Dang Chien

University of Dalat

Scaling down the body thickness (Tb) of double-gate tunnel field-effect transistors (DG-TFETs) is helpful in suppressing short-channel effects (SCEs), but it may give rise to thin-body effects (TBEs). Based on 2-D device simulations, this study examines the mechanisms and influences of TBEs in DG-TFETs as Tb is scaled down. Differently from previou...

In this study, we examined the influence of using hetero-gate dielectrics (HGDs) on the short-channel effects (SCEs) in scaled tunnel field-effect transistors (TFETs). For bulk TFETs, the short-channel performance is not influenced by the HGD engineering because the SCEs are caused by the tunneling at the region with negligible gate control. Howeve...

This work numerically elucidates the effects of transverse scaling on Schottky barrier charge-trapping cells for energy-efficient applications. Together with the scaled gate structures and charge-trapping dielectrics, variations in bias conditions on source-side injection are considered for properly operating Schottky barrier cells in low-power or...

Kỹ thuật điện môi cực cổng dị cấu trúc không chỉ giúp giảm dòng lưỡng cực mà còn làm tăng dòng mở của transistor trường xuyên hầm (tunnel field-effect transistr (TFET)). Dựa trên mô phỏng hai chiều, chúng tôi nghiên cứu vai trò và thiết kế của lớp điện môi dị cấu trúc trong TFET đơn và lưỡng cổng. Kết quả cho thấy vai trò và thiết kế của chuyển tiế...

The correct name of the third author should be given as Huu-Duy Tran, not Huy-Duy Tran.

The hetero-gate dielectric (HGD) structure was recently experimentally demonstrated to enhance the electrical performance of tunnel field-effect transistors (TFETs). This study examined the mechanisms underlying the HGD structure functioning and investigated the design of the structure to enhance the electrical characteristics of TFETs with differe...

Symmetric tunnel field-effect transistors (TFETs) have recently been proposed in order to make the design and fabrication of TFET-based circuits favorable. In this paper, we adequately investigate the device physics and design of point-tunneling TFETs with symmetric doping profiles. Based on two-dimensional numerical simulations, it is shown in the...

This paper examines the temperature effect of Schottky barrier source/drain charge-trapping memories. The current-voltage curves and programming/erasing characteristics are experimentally investigated at room temperature and higher 85 °C and 125 °C. 2-D device simulations were performed to elucidate the physical mechanisms of Schottky barrier cell...

This study examines the temperature effect of Schottky barrier source/drain charge-trapping memories. The current-voltage curves and programming/erasing characteristics are experimentally investigated at room temperature and higher 85∘C and 125∘C. Two-dimensional device simulations were performed to elucidate the physical mechanisms of Schottky bar...

Scaling down the bandgap is considered as an essential approach to enhance the performance of tunnel field-effect transistors (TFETs). Using two-dimensional simulations, this study examines the dependence of short-channel effects on the semiconductor bandgap in TFETs. It is shown that the short-channel effect is more severe with using lower bandgap...

This study investigates, by a two-dimensional simulation, the design optimization of a proposed 8 nm tunnel field-effect transistor (TFET) for low standby power (LSTP) applications utilizing graded Si/SiGe heterojunction with device parameters based on the ITRS specifications. The source Ge mole fraction should be designed approximately 0.8 because...

The onset behavior of output characteristics in tunnel field-effect transistors (TFETs) importantly determines the performance of digital TFET-based circuits. In this paper, we analytically and numerically examine the dependence of the onset behavior of output characteristics on the bandgap of semiconductors in line-tunneling TFETs. The qualitative...

Tunnel field-effect transistor (TFET) has recently been considered as a promising candidate for low-power integrated circuits. In this paper, we present an adequate examination on the roles of gate-oxide thickness reduction in scaling bulk and thin-body TFETs. It is shown that the short-channel performance of TFETs has to be characterized by both t...

Operated by the band-to-band tunneling at the source-channel junction, the source engineering has been considered as an efficient approach to enhance the performance of tunnel field-effect transistors (TFETs). In this paper, we report a new feature that the effects of source doping profile on the performance of single-and double-gate germanium TFET...

The nonlocal electric field approach has been widely accepted for Kane’s band-to-band tunneling (BTBT) model to calculate, both analytically and numerically, the tunneling current in tunnel field-effect transistors (TFETs). In this paper, we demonstrate that the tunneling current deviations of the local and nonlocal BTBT models from the mixed model...

Bài báo này trình bày một thuật toán tổng hợp có hệ thống nhằm tạo ra các mạch lọc đa năng bậc hai chế độ điện áp trên cơ sở phương pháp mở rộng ma trận. Tám mạch tương đương được tạo ra có thể thực hiện tất cả năm chức năng lọc cơ bản là lowpass, bandpass, highpass, notch và allpass sử dụng chỉ hai linh kiện tích cực. Các mạch được tạo ra có những...

The dimensional scaling of tunnel field-effect transistors (TFETs) is an indispensable issue to make them competitive with traditional metal-oxide-semiconductor field-effect transistors (MOSFETs). This paper elucidates the scalabilities of very potential TFETs utilizing Si/SiGe heterojunctions operated in n- and p-type operation modes. Although usi...

The two-band Kane model has been popularly used to calculate the band-to-band tunneling (BTBT) current in tunnel field-effect transistor (TFET) which is currently considered as a promising candidate for low power applications. This study theoretically clarifies the maximum electric field approximation (MEFA) of direct BTBT Kane model and evaluates...

Using low-bandgap semiconductors has been definitively designated as a key technique for boosting on-current of tunnel field-effect transistors (TFETs). Based on two-dimensional simulations, this study shows an upper limit of applied drain voltage and then investigates a method of drain design to allow of increasing the drain voltage for enhancing...

Unique short-drain effect was reported in extremely scaled tunnel field-effect transistors. This study numerically elucidated the short-drain effect and the difference between the short-channel and short-drain effects. For the short-drain effect, the off-state barriers reduce because of decreased drain lengths, generating ambipolar off-state...

The source doping engineering, the low bandgap material and the vertical tunneling structure have recently been considered as most effective techniques to resolve the on-current issue in tunnel field-effect transistors (TFETs). In this paper, the effects of source doping profile, including the concentration and gradient, on the device characteristi...

Owing to the breakthrough of the kT/q thermal limit of 60 mV/decade subthreshold swing at room temperature, tunnel field-effect transistors (TFETs) have demonstrated their potential for energy-efficient applications. Based on the clarified physical properties of band-to-band tunneling, this study demonstrates, both analytically and numerically, the...

The low-bandgap engineering and line-tunneling architecture are the two major techniques to resolve the ON-current issues of tunnel field-effect transistors (TFETs). This paper elucidates the design and modeling of line-tunneling TFETs using low-bandgap materials. Three semiconductors, Ge, InAs, and InSb, are considered as examples to explore their...

Low-bandgap semiconductors, such as InAs and InSb, are widely considered to be ideal for use in tunnel field-effect transistors to ensure sufficient on-current boosting at low voltages. This work elucidates the physical and mathematical considerations of applying conventional band-to-band tunneling models in low-bandgap semiconductors, and presents...

The heterostructure technique has recently demonstrated an excellent solution to resolve the trade-off between on- and off-state currents in tunnel field-effect transistors (TFETs). This paper shows the weakness of abrupt heterojunctions and explores the physics of drive current enhancement as well as generalizes the proposed graded heterojunction...

The energy bandgap is a key factor to determine the tunneling current in tunnel field-effect transistors (TFETs). This paper numerically investigates the effect of quantum confinement in the double-gate TFETs by evaluating the effective energy-band bandgap of the ultra-thin strained-Si1-xGex body. The band-offset caused by the quantum confinement e...

Using graded silicon-germanium heterojunctions, the green tunnel field-effect transistor (TFET) can be scaled down into sub-10 nm regimes without short-channel effects. This work elucidates numerically the physical operation and device design of extremely short-channel TFETs with graded silicon-germanium heterojunctions for future low-power and hig...

This work explores numerically the short-channel effects in thin-body SOI MOSFETs with shallow source/drain architecture, where the junction depths are less than the associated silicon body thicknesses. Unique fringing field and short-channel behavior are observed in the unconventional SOI devices. Numerical results of the short-channel effects are...

Tunnel field-effect transistor (TFET) has served as one of the most attractive candidates for use in future low-power integrated circuits. To explore the current-voltage characteristics of TFET devices, the Kane's tunnel model has been widely used in numerical simulations and physical models to predict the tunneling current produced in the TFETs. T...

This work explores the limitation of high-k gate insulator on improving the driving currents of MOSFETs. The use of high-k gate dielectric prevents from the gate tunneling current to have an acceptable EOT thickness in scaled devices. However, the effectiveness of continued EOT reduction is limited by the non-scalability of the quantum effect of in...

A new Schottky barrier (SB) nonvolatile nanowire memory is reported experimentally with efficient low-voltage pro- gramming and erasing. By applying an SB source/drain to enhance the electrical field in the silicon gate-all-around nanowire, the nonvolatile silicon-oxide-nitride-oxide-silicon (SONOS) memory can operate at gate voltages of 5 to 7 V f...

This study presents a new sub-10-nm tunnel field- effect transistor (TFET) with bandgap engineering using a graded Si/Ge heterojunction. Both the height and width of the tunneling barrier are highly controlled by applying gate voltages to ensure a near ideal sub-5-mV/dec switching of scaled sub-10-nm TFETs at 300 K. This study performed a 2-D simul...

This letter explores source-side injection in Schottky barrier metal-oxide-semiconductor (MOS) devices. Unlike drain-side injection in conventional MOS devices, a source-side lucky electron model predicts the specific source-side injection in Schottky barrier MOS devices. The source-side electric field is derived from the solutions of 2-D Poisson's...

The edge encroachment of tunnel oxide is experimentally found to degrade the Fowler-Nordheim (FN) tunneling gate current of NAND-type Flash cells. This work elucidates the impact of edge encroachment on FN tunneling current for use in programming and erasing operations. The fringing field effect and tunnel oxide with trapezoidal edge are considered...

The ambipolar conduction is numerically studied in recessed channel Schottky barrier MOSFET (RC-SBMOS). The results show that the recessed channel structure can alleviate the lateral field penetrations coming from drain electrode. Thus, it is rather insensitive to the variations of drain voltages. However, the parasitic recessed channel leads to a...

A coupled-channel analysis of the $^{18,20,22}$O$(p,p')$ data has been performed to determine the neutron transition strengths of 2$^+_1$ states in Oxygen targets, using the microscopic optical potential and inelastic form factor calculated in the folding model. A complex density- and \emph{isospin} dependent version of the CDM3Y6 interaction was c...