PolySi-SiO 2 -ZrO 2 -SiO 2 -Si Flash Memory Incorporating a Sol-Gel-Derived ZrO 2 Charge Trapping Layer

In this paper, we propose a method for depositing the charge trapping layer of a high-k polySi-SiO 2 -ZrO 2 -SiO 2 -Si ͑SOZOS͒ memory device. In this approach, the trapping layer was formed through simple two steps: ͑i͒ spin-coating of the ZrCl 4 precursor and ͑ii͒ rapid thermal annealing for 1 min at 900°C under an oxygen atmosphere. The morphology of the ZrO 2 charge trapping layer was confirmed through X-ray photoemission spectroscopy analysis. The sol-gel-derived layer exhibited improved charge trapping in the SOZOS memory device, resulting in a threshold voltage shift of 2.7 V in the I d -V g curve, P/E ͑program/erase͒ speeds as fast as 0.1 ms, good data retention up to 10 4 s ͑only a 5% charge loss due to deep trapping in the ZrO 2 layer͒, and good endurance ͑no memory window narrowing after 10 5 P/E cycles͒. © 2006 The Electrochemical Society. ͓DOI: 10.1149/1.2337846͔ All rights reserved. The first floating-gate ͑FG͒ nonvolatile semiconductor memory was invented by Sze and Kahng in 1967. 1 Conventional FG memory uses polysilicon as a charge-storage layer surrounded by the dielectric. 2 Although floating-gate structures can achieve high densities and good program/erase ͑P/E͒ speeds and exhibit good reliability in portable flash memory devices, there are concerns regarding the ability to scale up their production. 3 When the tunneling oxide thickness is below 10 nm, the storage charge in the FG leaks readily because defects form in the tunneling oxide after repeated write-erase cycles or through direct tunneling of the current. PolySi-oxide-nitride-oxide-silicon ͑SONOS͒ memory devices have been studied recently as an approach to solving the issue of scaling FG memory. 3 Because of their spatially isolated deep-level traps, SONOS memories exhibit better charge retention than do FG memories that have a bitcell tunneling oxide layer thinner than 10 nm. As a result, a single defect in the tunneling oxide will not cause the discharge of the memory cell. 3 SONOS memory devices use silicon nitride as a charge trapping layer; the conduction band offset between the tunneling oxide and nitride is 1.05 eV. When a positive voltage is applied on the gate, the band bends downward so that the electrons in the Si subconduction band will tunnel through the tunneling oxide and a portion of the nitride will become trapped in the charge trapping layer. Before they become trapped in the nitride, the electrons must tunnel through a portion of the nitride, which degrades the program speed. In addition, because the conduction band offset of the nitride is only 1.05 eV, back tunneling of the trapped electron may also occur. To solve these problems, high-k materials are potential candidates to replace the traditional silicon nitride as the charge trapping layer. The advantages of using high-k materials are the larger band offset with the tunneling oxide and the greater number of trapping sites than those found in silicon nitride. For an HfO 2 high-k material, the conduction band offset between the tunneling oxide and HfO 2 is 1.6 eV. When programming, the electron will tunnel through a shorter distance in HfO 2 than in the nitride to become trapped. This feature can be exploited to achieve high P/E speeds. Thus, it will be beneficial to use a high-k material as the charge trapping layer in a SONOS-type memory device, provided that there are many deep-level trapping sites in the high-k material. Many technologies have been developed recently for the deposition of high-k layers onto tunneling oxides, 7-10 including atomic layer deposition ͑ALD͒, metallorganic chemical vapor deposition ͑MOCVD͒, and physical vapor deposition ͑PVD͒. In the ALD method, ZrCl 4 and H 2 O are used to prepare the ZrO 2 films. For the PVD process, a zirconium metal target is used for sputtering under ambient oxygen to deposit the ZrO 2 films. In the CVD method, ZrCl 4 is used as a precursor to deposit ZrO 2 films. Recently, we proposed the first so-called sol-gel spin-coating method for the deposition of the thin film. 11 Sol-gel spin-coating methods use metal halides hydrolyzed in organic or colloidal solvents to form precursor compounds that undergo hydrolysis, condensation, and polymerization to form metal-oxide networks. The advantages of using sol-gel methods to fabricate high-k films are that they are cheaper than ALD, PVD, and MOCVD approaches, and that various types of thin films can be synthesized. To the best of our knowledge, sol-gel spin-coating of a high-k film has yet to be reported for the preparation of charge trapping layers for flash memory devices. In this paper, we describe the fabrication of a polySi-SiO 2 -ZrO 2 -SiO 2 -Si ͑SOZOS͒ flash memory device prepared through the deposition of ZrCl 4 using the sol-gel spin-coating method and subsequent rapid thermal annealing ͑RTA͒. We performed physical and electrical analyses, including X-ray photoemission spectroscopy ͑XPS͒, I d -V g , retention, and P/E speed measurements, to evaluate the performance of the sol-gel ZrO 2 films for their potential use as charge trapping layers in SOZOS memory devices. Experimental ZrCl 4 ͑99.5%, Aldrich, USA͒ was used as the synthetic precursor of the zirconia. A mother sol solution was first prepared by dissolving ZrCl 4 in isopropanol ͑IPA; Fluka; water content Ͻ0.1%͒ under vigorous stirring in an ice bath. The sol solution was obtained by fully hydrolyzing ZrCl 4 with a stoichiometric quantity of water in IPA to yield a Zr:IPA molar ratio of 1:1000. The fabrication of the sol-gel spin-coated SOZOS memory began with LOCOS isolation process on p-type 150 mm silicon ͑100͒ substrate. At first, a 4 nm tunneling oxide layer was grown thermally at 925°C through furnace oxidation. The Zr:IPA solution ͑molar ratio: 1:1000͒ was coated using a spin-coater at 3000 rpm for 60 s at 25°C. A TEL Clean Track model-MK8 ͑Japan͒ spin-coater was used. The as-deposited thin film was initially baked at 200°C for 10 min to perform densification, followed by high-k RTA for 1 min in an O 2 atmosphere to form the ZrO 2 charge trapping layer. The film thickness, measured using an ellipsometer, was 10 nm. A 30 nm thick blocking oxide was deposited using high-density-plasmaenhanced chemical vapor deposition ͑HDPCVD͒, followed by deposition of a poly-Si gate ͑200 nm͒. After gate deposition, the following processes were applied to fabricate the SOZOS memory: * Electrochemical Society Active Member.

Oncologic impact of delay between diagnosis and radical nephroureterectomy

PurposeThis study aimed to evaluate the oncological outcome of delayed surgical wait time from the diagnosis of upper tract urothelial carcinoma (UTUC) to radical nephroureterectomy (RNU).MethodsIn this multicenter retrospective study, medical records were collected between 1988 and 2021 from 18 participating Taiwanese hospitals under the Taiwan UTUC Collaboration Group. Patients were dichotomized into the early (≤90 days) and late (>90 days) surgical wait-time groups. Overall survival, disease-free survival, and bladder recurrence-free survival were calculated using the Kaplan–Meier method and multivariate Cox regression analysis. Multivariate analysis was performed using stepwise linear regression.ResultsOf the 1251 patients, 1181 (94.4%) were classifed into the early surgical wait-time group and 70 (5.6%) into the late surgical wait-time group. The median surgical wait time was 21 days, and the median follow-up was 59.5 months. Our study showed delay-time more than 90 days appeared to be associated with worse overall survival (hazard ratio [HR] 1.974, 95% confidence interval [CI] 1.166−3.343, p = 0.011), and disease-free survival (HR 1.997, 95% CI 1.137−3.507, p = 0.016). This remained as an independent prognostic factor after other confounding factors were adjusted. Age, ECOG performance status, Charlson Comorbidity Index (CCI), surgical margin, tumor location and adjuvant systemic therapy were independent prognostic factors for overall survival. Tumor location and adjuvant systemic therapy were also independent prognostic factors for disease-free survival.ConclusionsFor patients with UTUC undergoing RNU, the surgical wait time should be minimized to less than 90 days. Prolonged delay times may be associated with poor overall and disease-free survival

4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

<p>Abstract</p> <p>Background</p> <p>The crude extract of the fruit bearing plant, <it>Physalis peruviana </it>(golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown.</p> <p>Methods</p> <p>Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug.</p> <p>Results</p> <p>It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (<it>p </it>< 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (<it>p </it>< 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC₅₀) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G₁accumulation and slight arrest at the G₂/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G₂/M arrest for H1299 cells treated with 5 μg/mL for 24 h.</p> <p>Conclusions</p> <p>In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.</p

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Low-Temperature, Solution-Processed, Transparent Zinc Oxide-Based Thin-Film Transistors for Sensing Various Solvents

A low temperature solution-processed thin-film transistor (TFT) using zinc oxide (ZnO) film as an exposed sensing semiconductor channel was fabricated to detect and identify various solution solvents. The TFT devices would offer applications for low-cost, rapid and highly compatible water-soluble detection and could replace conventional silicon field effect transistors (FETs) as bio-sensors. In this work, we demonstrate the utility of the TFT ZnO channel to sense various liquids, such as polar solvents (ethanol), non-polar solvents (toluene) and deionized (DI) water, which were dropped and adsorbed onto the channel. It is discussed how different dielectric constants of polar/non-polar solvents and DI water were associated with various charge transport properties, demonstrating the main detection mechanisms of the thin-film transistor

The re-explore of the industrial design protection system- the rationality of protection of industrial design under patent law

「工業設計」於國際智慧財產組織之意義，係指對於物品之外觀產生之視覺效果之創作，各國均以智慧財產權予以保護，我國係將其以「設計專利」予以保護。良好之物品外觀設計，將使商品於市場上能快速吸引消費者之眼光並選購，尤其我國目前已經入發展「文創產業」之時代，市場上衣充斥各種外觀經過精心設計之商品，工業設計之保護制度是否適切，乃係十分重要之議題。 本論文以工業設計發展之歷史歷史切入，發現係因工業革命後，生產方式由傳統少量之手工製作，轉變為運用機械而大量生產之情況，而其保護者主要係「視覺性」之創作，其與保護「技術創作」之專利制度顯然不同，我國法將其歸為專利之一種，顯有疑問。經本論文分析現行法規範後，發現對於工業設計之保護，於保護客體、保護要件、審查程序與侵害鑑定四大層次中，均與以技術創作為導向之「專利」毫無關聯，以專利法予以保護，顯然更加體現工業設計「客子」或「寄養」之地位。 我國法因歷史因素，以「設計專利」制度，強行將工業設計規範於專利法中，長期下來之結果，不但造成體系定位之錯誤，更造成對於工業設計之誤解，忽略其本身係保護「視覺性創作」之本質。而此種結果，亦造成工業設計並無自己之主體性，以促進產業發展之角度而言，將造成工業設計被歸類為專利法之一支，而無適宜之規範供業界利用。本論文認為，主管機關應針對工業設計重行理解，本於產業界之需求，妥適規劃關於其保護目的、構成要件、審查程序、侵害判斷之準則，以及架設規費、註冊或登記等管理制度，祈能藉此重新建立正確之智慧財產權法體系，達到促進國家設計發展之目的。The meaning of “industrial design” in the World Intellectual Property Organization refers to the creation of visual effects produced by the outward appearance of an article, which is protected in countries all over the world by intellectual property rights. In Taiwan, however, industrial designs are protected by “design patents.” A good design of an article’s appearance can help a product to quickly catch the eyes of the purchasing consumers in the market. As Taiwan has now entered the era of “cultural and creative industry,” where the market is filled with all sorts of products that have well-designed appearances, whether the protection system for industrial designs is appropriate has become a very important issue. This thesis begins with the history of industrial design and discusses how the method of production has transformed from traditional handicraft manufactures to mass machinery production due to the Industrial Revolution; what needs to be protected in industrial design is mainly its “visual” creation, which is obviously different from “technical creations” protected by the patent system. Thus, classifying industrial design as a type of patent is questionable. Having analyzed the norms of the laws now in force, this thesis finds that with respect to the protection of industrial design, the four main dimensions of object of protection, protection requirements, review procedures, and infringement assessment are all unrelated to the technical creation-oriented “patents”. Protecting industrial design with the Patent Act further enforces its “guest” or “foster” status. For historical reasons, Taiwanese laws, based on the “design patent” system, placed industrial design under the Patent Act. Over the years, this has not only resulted in mispositioning industrial design but has also contributed to the misunderstanding of industrial design, overlooking that protection lies in protecting the essence of “visual creation”. This also causes industrial design to lose its subjectivity. In terms of promoting industrial development, this renders industrial design to be categorized as a branch of the Patent Act, with no proper norms for the industry to rely on. This thesis holds that the authorities in charge should rethink the meaning of industrial design. Based on the needs of the industry, the criteria regarding the purpose of the protection, the element requirements, the apply procedures, and the infringement judgment should all be developed. A management system should be created to handle charges, fees, applications, and registrations. It is hoped that through the above recommendations, a proper intellectual property rights system can be established while supporting the goal of facilitating the country’s design development

Exercise Effects on Autonomic Nervous System Activity in Type 2 Diabetes Mellitus Patients over Time: A Meta-Regression Study

Background: Diabetic autonomic neuropathy is a common complication of type 2 diabetes mellitus (T2DM), especially in patients with long-term, poorly controlled diabetes. This study investigates the effects of exercise on autonomic nervous system activity in T2DM patients over time. Methods: A literature review using MEDLINE, Embase, Cochrane Library, Scopus, and PubMed identified studies assessed via heart rate variability. Papers were categorized into three groups: immediate effects (within 60 min), short-term effects (2–3 months), and long-term effects (over 4 months). Results: Nine articles with 161 T2DM patients were included in the meta-analysis. RMSSD changes after exercise were −4.3 (p = 0.227), 8.14 (p p = 0.002) for the immediate, short-term, and long-term groups, respectively. LF/HF ratio changes were 0.21 (p = 0.264), −3.04 (p = 0.102), and −0.05 (p = 0.006) for the respective groups. Meta-regression indicated age, male gender, and exercise duration were associated with increased RMSSD, with coefficients of 2.36 (p = 0.001), 13.76 (p = 0.008), and 1.50 (p = 0.007), respectively. Age positively correlated with the LF/HF ratio, with a coefficient of 0.049 (p = 0.048). Conclusions: Regular exercise (≥3 times per week) for over 2 months increases parasympathetic activity in T2DM patients, while sympathetic activity decreases significantly after 4 months. Further study is needed to validate these findings

Process Research On Cone-Shaped Micro-Nano Structures

In this study, the manufacturing methods and imaging principles of cone-shaped arrays of micro-nano structure films were examined. Because optical films fabricated using cone-shaped arrays of micro-nano structures generate a double diffusion and produce diverse light effects on light sources, these optical films can be used effectively to enhance optical efficiency and can thus be used widely in liquid crystal displays. The experimental steps for producing cone-shaped arrays of micro-nano-structure films were as follows: First, a silicon wafer was spun off water, bake-dried, and applied with a photoresist coating, which was soft-baked on a hot plate. Next, the photoresist layer was exposed to light by using a stepper, and the wafer was then developed and hard-baked on a hot plate to produce cone-shaped arrays of micro-nano-structure films. This study proposes for the first time an exposure method applied on a wafer in which focus and exposure dosage of light are adjusted to produce films of cone-shaped micro-nano structures with distinct slopes. Using this method, films can be manufactured through micro-evolutionary changes in the array structure

Process Research On Cone-Shaped Micro-Nano Structures

Abstract: In this study, the manufacturing methods and imaging principles of cone-shaped arrays of micro-nano structure films were examined. Because optical films fabricated using cone-shaped arrays of micro-nano structures generate a double diffusion and produce diverse light effects on light sources, these optical films can be used effectively to enhance optical efficiency and can thus be used widely in liquid crystal displays. The experimental steps for producing cone-shaped arrays of micro-nano-structure films were as follows: First, a silicon wafer was spun off water, bake-dried, and applied with a photoresist coating, which was soft-baked on a hot plate. Next, the photoresist layer was exposed to light by using a stepper, and the wafer was then developed and hard-baked on a hot plate to produce cone-shaped arrays of micro-nano-structure films. This study proposes for the first time an exposure method applied on a wafer in which focus and exposure dosage of light are adjusted to produce films of cone-shaped micro-nano structures with distinct slopes. Using this method, films can be manufactured through micro-evolutionary changes in the array structure