Electrostatic Doping in Semiconductor Devices

Gupta, Gaurav; Rajasekharan, B.; Hueting, R.J.E.

doi:10.1109/ted.2017.2712761

Cited by 125 publications

(98 citation statements)

References 89 publications

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“…However, one may consider also alternative mechanisms where the relative separation between the E F and E C directly in the HEMT QW channel governs the free electron concentration, and not the real-space electron transfer from the surface or volume of the barrier layer. Similar mechanism applies for e.g., electrostatic doping in Schottky contact structures, [7] charge accumulation in ordinary MOS/MIS structures [8] and may actually appear also in strongly polarized III-N QW heterostructures.…”

Section: Introductionmentioning

confidence: 87%

Creation of Two‐Dimensional Electron Gas and Role of Surface Donors in III‐N Metal‐Oxide‐Semiconductor High‐Electron Mobility Transistors

Gucmann

Ťapajna

Pohorelec

et al. 2018

Physica Status Solidi (a)

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The role of surface donors at the oxide/semiconductor interface of III‐N metal‐oxide‐semiconductor (MOS) high‐electron mobility transistors (HEMTs), by creating a two‐dimensional electron gas (2DEG) and the device performance, are investigated. Al2O3/GaN/AlGaN/GaN MOS HEMTs show the surface donor density (Nd,surf) of 2.2 × 1013 cm−2, which is increased up to 3.4 × 1013 cm−2 after post‐deposition annealing. In the latter, surface donors fully compensate the surface polarization charge and the HEMT threshold voltage decreases substantially with the oxide thickness. On the other hand, an open‐channel drain current is found to be independent of Nd,surf, while marginal trapping is completely removed when Nd,surf increases with annealing. Consequently, ionized surface donors behave like a fixed charge and are clearly distinguishable from trapping states. Open‐channel 2DEG densities of ≈1.1 × 1013 cm−2 are extracted from capacitance–voltage measurements. Similarly, recent data on enhancement‐mode HfO2/InAlN/AlN/GaN MOS HEMTs are analyzed where Nd,surf is reduced down to 1 × 1013 cm−2 while 2DEG densities reach ≈2.7 × 1013 cm−2. It is suggested that under the open‐channel condition, 2DEG is supplied also by an injecting source contact if Nd,surf is lower than the QW polarization charge. Our charge quantifications are supported by calculating energy‐band diagrams.

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Section: Introductionmentioning

confidence: 87%

Creation of Two‐Dimensional Electron Gas and Role of Surface Donors in III‐N Metal‐Oxide‐Semiconductor High‐Electron Mobility Transistors

Gucmann

Ťapajna

Pohorelec

et al. 2018

Physica Status Solidi (a)

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“…14,17 Further, in nano-regime, another constraint is the realization of abrupt doping profile using chemical doping method (both for the MOSFET and the TFET), which increases the thermal budget and hence requires expensive annealing techniques. One possible solution emerging is the use of electrostatic doping (ED) concept, 18 wherein, gate electrode with proper work functions are used for realizing the required doping. Recently, this class of promising ED devices are studied extensively and are either called the junction-less (JL) [19][20][21][22][23][24][25] TFET or the charge-plasma (CP) [26][27][28][29] based Tunnel-FETs, to overcome the limitation of traditional chemical doping process.…”

Section: Introductionmentioning

confidence: 99%

Electrostatically doped drain engineered DG‐TFET: Proposal and analysis

Shaikh

Loan

Alshahrani

2020

Int J Numerical Modelling

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In this paper, a drain-engineered double-gate Tunnel-FET (DE-DG-TFET) to enhance the electrical characteristics and analog parameters of a conventional DG-TFET is proposed and examined through calibrated TCAD simulations. Unlike DG-TFET, a constant n-type doping, N cd , (5 × 10 17 cm −3 − 2 × 10 18 cm −3), in the channel/drain regions of DE-DG-TFET is used, resulting in a p +-n-n structure instead of conventional p +-in structure. Further, p +-n-n is modified to p +-nn + using electrostatic doping (ED) method on the drain side with Hafnium (ϕ m = 3.9 eV) as a lateral (top and bottom) and side metal electrode. A high n +-drain doping ensures the drain contact remains ohmic. Higher electric field at p +-n source-channel junction enhances the ON-state BTBT current. While the absence of metallurgical junction provides large tunneling width across the channel/drain junction, resulting in suppression of ambipolar current (I AMB). At N cd doping of 1 × 10 18 cm −3 , DE-DG-TFET demonstrates 7 times increase in I ON while I AMB is suppressed by 5 orders of magnitude. In addition to this, the proposed device improves analog/RF figures of merit, 45% in voltage gain and 5 times in peak f T. K E Y W O R D S ambipolarity, band-to-band tunneling (BTBT), charge plasma, electrostatic doping (ED), JLTFET

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“…Novel to this work, the capacitor is integrated with the AlGaN material system, forming a UV EFELED. The operation of the capacitor is analogous to that of the gate in a field effect transistor (FET), where charges can be attracted or repelled [14][15]. The width of the depletion region (W) where charges are attached or repelled can be found through Eq.…”

Section: Introductionmentioning

confidence: 99%

Ultraviolet Electrostatic Field Effect Light-Emitting Diode

2020

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The potential of ultraviolet (UV) AlGaN quantum well (QW) light-emitting diodes (LEDs) is stunted due to the lack of efficient p-type doping for this ultra wide bandgap material. In this work, a novel device-UV electrostatic field effect LED (EFELED) is demonstrated to address this issue by significantly improving hole injection into the QW active region which leads to a relative increase of external quantum efficiency (EQE) up to 42%. The UV EFELED is realized by integrating a capacitor layer on top of a conventional 267 nm AlGaN QW LED, which introduces band bending to assist hole injection under a forward bias. A 10x increase in injection current is achieved through the application of a positive bias to the integrated capacitor layer. With 20 V applied to the capacitor, a 42% increase of EQE is achieved. Photon intensity modulation is demonstrated with the application of varying capacitor biases, which presents a novel brightness control at UV wavelength. Thus, the proposed UV EFELED provides significantly improved hole injection through a capacitor integration, which leads to high-efficiency UV LEDs for important applications such as sterilization and purification.

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Electrostatic Doping in Semiconductor Devices

Cited by 125 publications

References 89 publications

Creation of Two‐Dimensional Electron Gas and Role of Surface Donors in III‐N Metal‐Oxide‐Semiconductor High‐Electron Mobility Transistors

Creation of Two‐Dimensional Electron Gas and Role of Surface Donors in III‐N Metal‐Oxide‐Semiconductor High‐Electron Mobility Transistors

Electrostatically doped drain engineered DG‐TFET: Proposal and analysis

Ultraviolet Electrostatic Field Effect Light-Emitting Diode

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