Search Results (8)

Silicon nanowire field effect (SiNW-FET) biosensors have been successfully used in the detection of nucleic acids, proteins and other molecules owing to their advantages of ultra-high sensitivity, high specificity, and label-free and immediate response. However, the presence of the Debye shielding effect in semiconductor devices severely reduces their detection sensitivity. In this paper, a three-dimensional stacked silicon nanosheet FET (3D-SiNS-FET) biosensor was studied for the high-sensitivity detection of nucleic acids. Based on the mainstream Gate-All-Around (GAA) fenestration process, a three-dimensional stacked structure with an 8 nm cavity spacing was designed and prepared, allowing modification of probe molecules within the stacked cavities. Furthermore, the advantage of the three-dimensional space can realize the upper and lower complementary detection, which can overcome the Debye shielding effect and realize high-sensitivity Point of Care Testing (POCT) at high ionic strength. The experimental results show that the minimum detection limit for 12-base DNA (4 nM) at 1 × PBS is less than 10 zM, and at a high concentration of 1 µM DNA, the sensitivity of the 3D-SiNS-FET is approximately 10 times higher than that of the planar devices. This indicates that our device provides distinct advantages for detection, showing promise for future biosensor applications in clinical settings. Full article

This paper examines the performance of a Gate-Engineered Gate-All-Around Charge Plasma Nanowire Field Effect Transistor (GAA-DMG-GS-CP NW-FET) and the implementation of a common source (CS) amplifier circuit. The proposed GAA-DMG-GS-CP NW-FET incorporates dual-material gate (DMG) and gate stack (GS) as gate engineering techniques and its analog/RF performance parameters are compared to those of the Gate-All-Around Single-Material Gate Charge Plasma Nanowire Field Effect Transistor (GAA-SMG-CP NW-FET) device. Both Gate-All-Around (GAA) devices are designed using the Silvaco TCAD tool. GAA structures have demonstrated good gate control because the gate holds the channel, which is an inherent advantage for both devices discussed herein. The charge plasma dopingless technique is used, in which the source and drain regions are formed using metal contacts and necessary work functions rather than doping. This dopingless technique eliminates the need for doping, reducing fluctuations caused by random dopants and lowering the device’s thermal budget. Gate engineering techniques such as DMG and GS significantly improved the current characteristics which played a crucial role in obtaining maximum gain for circuit designs. The lookup table (LUT) approach is used in the implementation of the CS amplifier circuit with the proposed device. The transient response of the circuit is analyzed with both the device structures where the gain achieved for the CS amplifier circuit using the proposed GAA-DMG-GS-CP NW-FET is 15.06 dB. The superior performance showcased by the proposed GAA-DMG-GS-CP NW-FET device with analog, RF and circuit analysis proves its strong candidature for future nanoscale and low-power applications. Full article

In this study, the effects of the total ionizing dose (TID) on a nanowire (NW) field-effect transistor (FET) and a nanosheet (NS) FET were analyzed. The devices have Gate-all-around (GAA) structure that are less affected by TID effects because GAA structures have better gate controllability than previously proposed structures, such as planar MOSFETs and FinFETs. However, even for GAA devices with the same channel cross-sectional area and equivalent oxide thickness, structural differences can exist, which can result in different tolerances of TID effects. To observe the device and circuit operation characteristics of these GAA devices with structural differences, n-type and p-type devices were designed and simulated. The circuit simulation according to TID effects was conducted using Berkeley short-channel insulated-gate FET model (BSIM) common multi-gate (CMG) parameters. The NS-FET generated more V_T shift than the NW-FET because the NS-FET had a wider gate oxide area and channel circumference, resulting in more interface hole traps. The abnormal V_T shift leads to causing unstable circuit operation and delays. Therefore, it was confirmed that the ability of the NW-FET to tolerate TID effects was better than that of the NS-FET. Full article

A 16-nm-L_g p-type Gate-all-around (GAA) silicon nanowire (Si NW) metal oxide semiconductor field effect transistor (MOSFET) was fabricated based on the mainstream bulk fin field-effect transistor (FinFET) technology. The temperature dependence of electrical characteristics for normal MOSFET as well as the quantum transport at cryogenic has been investigated systematically. We demonstrate a good gate-control ability and body effect immunity at cryogenic for the GAA Si NW MOSFETs and observe the transport of two-fold degenerate hole sub-bands in the nanowire (110) channel direction sub-band structure experimentally. In addition, the pronounced ballistic transport characteristics were demonstrated in the GAA Si NW MOSFET. Due to the existence of spacers for the typical MOSFET, the quantum interference was also successfully achieved at lower bias. Full article

In this study, we analyzed the total ionizing dose (TID) effect characteristics of p-type FinFET and Nanowire FET (NW-FET) according to the structural aspect through comparison of the two devices. Similar to n-type devices, p-type NW-FETs are less affected than FinFETs by the TID effect. For the inverter TID circuit simulation, both n- and p-types of FinFET and NW-FET were analyzed regarding the TID effect. The inverter operation considering the TID effect was verified using the Berkeley short-channel insulated-gate FET model (BSIM) common multi-gate (CMG) parameters. In addition, an inverter circuit composed of the NW-FET exhibited a smaller change by the TID than that of an inverter circuit composed of the FinFET. Therefore, the gate controllability of the gate-all-around (GAA) device had an excellent tolerance to not only short-channel effects (SCE) but also TID effects. Full article

We introduce a single-grain gate-all-around (GAA) Si nanowire (NW) FET using the location-controlled-grain technique and several innovative low-thermal budget processes, including green nanosecond laser crystallization, far-infrared laser annealing, and hybrid laser-assisted salicidation, that keep the substrate temperature (T_sub) lower than 400 °C for monolithic three-dimensional integrated circuits (3D-ICs). The detailed process verification of a low-defect GAA nanowire and electrical characteristics were investigated in this article. The GAA Si NW FETs, which were intentionally fabricated within the controlled Si grain, exhibit a steeper subthreshold swing (S.S.) of about 65 mV/dec., higher driving currents of 327 µA/µm (n-type) and 297 µA/µm (p-type) @ V_th ± 0.8 V, and higher I_on/I_off (>10⁵ @|V_d| = 1 V) and have a narrower electrical property distribution. In addition, the proposed Si NW FETs with a GAA structure were found to be less sensitive to V_th roll-off and S.S. degradation compared to the omega(Ω)-gate Si FETs. It enables ultrahigh-density sequentially stackable integrated circuits with superior performance and low power consumption for future mobile and neuromorphic applications. Full article

The temperature dependent carrier transport characteristics of n-type gate-all-around nanowire field effect transistors (GAA NW-FET) on bulk silicon are experimentally compared to bulk fin field effect transistors (FinFET) over a wide range of temperatures (25–125 °C). A similar temperature dependence of threshold voltage (V_TH) and subthreshold swing (SS) is observed for both devices. However, effective mobility (μ_eff) shows significant differences of temperature dependence between GAA NW-FET and FinFET at a high gate effective field. At weak N_inv (= 5 × 10¹² cm²/V∙s), both GAA NW-FET and FinFET are mainly limited by phonon scattering in μ_eff. On the other hand, at strong N_inv (= 1.5 × 10¹³ cm²/V∙s), GAA NW-FET shows 10 times higher dμ_eff/dT and 1.6 times smaller mobility degradation coefficient (α) than FinFET. GAA NW-FET is less limited by surface roughness scattering, but FinFET is relatively more limited by surface roughness scattering in carrier transport. Full article

Analysis of the radiation effects in a device is of great importance. The gate all around (GAA) structure that contributes to device scaling not only solves the short channel effects (SCE) problem but also makes the device more resistant in radiation environments. In this article, the total ionizing dose (TID) simulation of nanowire FET (NW) and FinFET was performed. Both these devices were compared and analyzed in terms of the shift of threshold voltage (V_T). The channel insulator was composed of two materials, SiO₂ and HfO₂. To improve the accuracy of the simulation, the interfacial trap parameter of SiO₂ and HfO₂ was applied. Based on the simulation result, the NW with a larger oxide area and larger gate controllability showed less V_T shift than that of the FinFET. It was therefore proved that NW had better TID resistance characteristics in a radiation environment. The gate controllability was found to affect the TID effect more than the oxide area. In addition, we analyzed the manner in which the TID effect changed depending on the V_DD and channel doping. Full article