First Demonstration of Ultra-Thin SiGe-Channel Junctionless Accumulation-Mode (JAM) Bulk FinFETs on Si Substrate with PN Junction-Isolation Scheme

A SiGe-channel junctionless-accumulation-mode (JAM) PMOS bulk FinFETs were successfully demonstrated on Si substrate with PN junction-isolation scheme for the first time. The JAM bulk FinFETs with fin width of 18 nm exhibits excellent subthreshold characteristics such as subthreshold swing of 64 mV/decade, drain-induced barrier lowering (DIBL) of 40 mV/V and high Ion/Ioff current ratio ( \u3e 1 x 105). The change of substrate bias from 0 to 5 V leads to the threshold voltage shift of 53 mV by modulating the effective channel thickness. When compared to the Si-channel bulk FinFETs with fin width of 18 nm, Si and SiGe channel devices exhibits comparable subthreshold swing and DIBL. For devices with longer fin width, SiGe channel devices exhibits much lower DIBL, indicating superior top-gate controllability and robustness to substrate bias compared to the Si channel devices. A zero temperature coefficient point was observed in the transfer curves as temperature increases from -120 to 120°C, confirming that mobility degradation is dominantly affected by phonon scattering mechanism

Comparisons of the Effects of Stent Eccentricity on the Neointimal Hyperplasia between Sirolimus-Eluting Stent versus Paclitaxel-Eluting Stent

PURPOSE: Previous studies suggested that asymmetric stent expansion did not affect suppression of neointimal hyperplasia (NIH) after sirolimus-eluting stents (SES) implantation. The aim of this study was to evaluate the effects of stent eccentricity (SE) on NIH between SES versus paclitaxel-eluting stents (PES) using an intravascular ultrasound (IVUS) analysis from the randomized trial. MATERIALS AND METHODS: Serial IVUS data were obtained from Post-stent Optimal Expansion (POET) trial, allocated randomly to SES or PES. Three different SE (minimum stent diameter divided by maximum stent diameter) were evaluated; SE at the lesion site with maximal %NIH area (SE-NIH), SE at the minimal stent CSA [SE-minimal stent area (SE-MSA)], and averaged SE through the entire stent (SE-mean). We classified each drug-eluting stents (DES) into the concentric (≥ mean SE) and eccentric groups (< mean SE) based on the mean value of SE. RESULTS: Among 301 enrolled patients, 233 patients [SES (n = 108), PES (n = 125)] underwent a follow-up IVUS. There was no significant correlation between %NIH area and SE-NIH (r = - 0.083, p = 0.391) or SE-MSA (r = - 0.109, p = 0.259) of SES. However, SE-NIH of PES showed a weak but significant correlation with %NIH area (r = 0.269, p < 0.01). As to the associations between SEmean and NIH volume index, SES revealed no significant correlation (r = - 0.001, p = 0.990), but PES showed a weak but significant correlation (r = 0.320, p < 0.01). However, there was no difference in the restenosis rate between the eccentric versus concentric groups of both DES. CONCLUSION: This study suggests that lower SE of both SES and PES, which means asymmetric stent expansion, may not be associated with increased NIH.ope

Origin of Device Performance Enhancement of Junctionless Accumulation-Mode (JAM) Bulk FinFETs with High-Κ Gate Spacers

In this letter, we investigated the junctionless accumulation-mode (JAM) bulk FinFETs with high-κ gate spacers showing enhanced device performance in SS, DIBL, and ON/OFF current ratio. We found that origin of the ON-state current enhancement was reduction of the initial energy barrier between the source and channel, and reason for the OFF-state current reduction was L G extension caused by the fringing field through high-κ gate spacers. The off-state leakage current decreased by over one order of magnitude. The ON-state current was remarkably enhanced by 180% over that of low-κ gate spacers. The high-κ gate spacer is indispensable for enhancing the performance of the JAM field-effect transistor in a sub 20-nm -gate length regime

Triboelectric Nanogenerator Based on the Internal Motion of Powder with a Package Structure Design

Harvesting the ambient mechanical energy that is abundant in the living environment is a green technology which can allow us to obtain an eco-friendly and sustainable form of energy. Here, we report a powder-based triboelectric nanogenerator (P-TENG) using polytetrafluoroethylene powder as a freestanding triboelectric layer. By employing powder, which has fluid-like characteristics, the device is able to harvest random vibrational energy from all directions and can be fabricated regardless of the size or shape of its container. Notably, this device shows excellent durability against mechanical friction and immunity against humidity. It is also capable of powering 240 green LEDs and charging a commercial energy-harvesting battery. The P-TENG is expected to be applicable as an energy harvester in self-powered systems for the upcoming Internet-of-Things era

Germanium electron-hole bilayer tunnel field-effect transistors with a symmetrically arranged double gate

A germanium tunnel field-effect transistor (TFET) with a bias-induced electron-hole bilayer (EHB) with double gates that are symmetrically arranged and independently biased is simulated. The symmetric double gate scheme is feasible, presenting a simple EHB-TFET structure that is practicable for industrial fabrication. According to simulation results, the improvement of on/off current ratio of similar to 10(8) is achieved by inserting a lightly-doped drain-source (LDD) region. Also, fin-type EHB-TFETs show an extremely low average sub-threshold swing of 11 mV/decade over 4 decades at V-DD = 0.5 V, and thus are suitable for ultra-low power applications.N

Enhanced Device Performance of Germanium Nanowire Junctionless (GeNW-JL) MOSFETs by Germanide Contact Formation with Ar Plasma Treatment

In this study, germanium nanowire junctionless (GeNW-JL) metal-oxide-semiconductor-field-effect-transistors (MOSFETs) exhibited enhanced electrical performance with low source/drain (S/D) contact resistance under the influence of Ar plasma treatment on the contact regions. We found that the transformation of the surface oxide states by Ar plasma treatment affected the S/D contact resistance. With Ar plasma treatment, the germanium dioxide on the GeNW surface was effectively removed and increased oxygen vacancies were formed in the suboxide on the GeNW, whose germanium-enrichment surface was obtained to form a germanide contact at low temperature. After a rapid thermal annealing process, Ni-germanide contacts were formed on the Ar-plasma-treated GeNW surface. Ni-germanide contact resistance was improved by more than an order of magnitude compared to that of the other devices without Ni-germanide contact. Moreover, the peak field effect mobility value of the GeNW-JL MOSFETs was dramatically improved from 15 cm²/(V s) to 550 cm²/(V s), and the <i>I</i>_on/off ratio was enhanced from 1 × 10 to 3 × 10³ due to Ar plasma treatment. The Ar plasma treatment process is essential for forming uniform Ni-germanide-contacts with reduced time and low temperature. It is also crucial for increasing mass productivity and lowering the thermal budget without sacrificing the performance of GeNW-JL MOSFETs