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BACKGROUND Global warming and extreme or adverse events induced by climatic fluctuations are an important threat for plants growth and agricultural production. Adaptability to environmental changes prevalently derives from a large set of genetic traits affecting physiological and agronomic parameters. Therefore, the identification of genotypes that are good yield performer at high temperatures is becoming increasingly necessary for future breeding programs. Here, we analyzed the performances of different tomato landraces grown under elevated temperatures in terms of yield and nutritional quality of the fruit. Finally, we evaluated the antioxidant and anti‐inflammatory activities of fruit extracts from the tomato landraces selected. RESULTS The tomato landraces analyzed here in a hot climate differed in terms of yield performance, physicochemical parameters of fruit (pH, titratable acidity, degrees Brix, firmness), bioactive compounds (ascorbic acid, carotenoids, and polyphenols), and anti‐inflammatory potential. Three of these landraces (named E30, E94, and PDVIT) showed higher fruit quality and nutritional value. An estimated evaluation index allowed identification of PDVIT as the best performer in terms of yield and fruit quality under high temperatures. CONCLUSION The analyses performed here highlight the possibility to identify new landraces that can combine good yield performances and fruit nutritional quality at high temperatures, information that is useful for future breeding programs. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Background Trabectedin, in addition to its antiproliferative effect, can modify the tumour microenvironment and this could be synergistic with bevacizumab. The efficacy and safety of trabectedin and bevacizumab ± carboplatin have never been investigated. Methods In this phase 2 study, women progressing between 6 and 12 months since their last platinum-based therapy were randomised to Arm BT: bevacizumab, trabectedin every 21 days, or Arm BT+C: bevacizumab, trabectedin and carboplatin every 28 days, from cycles 1 to 6, then trabectedin and bevacizumab as in Arm BT. Primary endpoints were progression-free survival rate (PFS-6) and severe toxicity rate (ST-6) at 6 months, assuming a PFS-6 ≤35% for BT and ≤40% for BT+C as not of therapeutic interest and, for both arms, a ST-6 ≥ 30% as unacceptable. Results BT+C (21 patients) did not meet the safety criteria for the second stage (ST-6 45%; 95%CI: 23%–69%) but PFS-6 was 85% (95%CI: 62%–97%). BT (50 patients) had 75% PFS-6 (95%CI: 60%–87%) and 16% ST-6 (95%CI 7%–30%). Conclusions BT compared favourably with other platinum- and non-platinum-based regimens. The combination with carboplatin needs to be assessed further in a re-modulated safer schedule to confirm its apparent strong activity. Clinical Trial Registration NCT01735071 (Clinicaltrials.gov).

Scope Polyphenols exhibit their antioxidant activity downstream the activation of the Nuclear factor erythroid 2-related factor 2 pathway (Nrf2) but their ability to modulate lipid metabolism via this mechanism has been limitedly investigated. We hypothesized that flavonoids-rich concentrated extract from Prunus mahaleb(mcfe) may improve oxido-reductive homeostasis and modulate hepatic lipid metabolism via Nrf2. Methods & Results Mcfe ability to enhance the activity of Nrf2-mediated antioxidant/detoxifying enzymes was examined in liver and colon of BALB/c mice upon a 4-weeks supplementation. Macroscopic, histological and biochemical signs of colitis were examined in mouse colon pulsed with 5% (w/v) Dextran Sodium Sulphate(DSS) at the end of mcfe treatment. Untreated or DSS-supplemented mice were used negative or positive control. Mcfe effect on liver lipid metabolism was investigated and the possible link between with the Nrf2 pathway was finally examined. Mcfe intake increased antioxidant defenses in mice colon and its pre-treatment blunted pathological signs of colitis, as compared to positive control. In the liver, the increase in antioxidant defenses was associated with enhanced oxidative metabolism and with higher levels of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PGC-1alpha) and of hemeoxygenase-1(HO-1), in comparison with negative controls. Conclusion Cytoprotective and hypolipidemic effect produced by mcfe intake are, at least in part, associated with the activation of the Nrf2 pathway.

Many marine organisms, including invertebrates, produce mucosal matrices having different functions. Besides mechanical protection, the mucus of many invertebrates contains specific compounds to make the animal poisonous and/or distasteful or irritating. The presence of antibiotic molecules is more advantageous for some invertebrates to contrast bacterial attack. In the present study we investigated the mucus of the Mediterranean annelid species Myxicola infundibulum living in a gelatinous envelope made up of dense mucus. Antimicrobial lysozyme-like and antioxidant activities were investigated to highlight the potential interest of the worm mucus as a source of bioactive compounds for biotechnological applications. In order to understand which kind of compounds could be responsible for the detected activities, the mucus of M. infundibulum was chemically characterized in terms of elemental composition, protein, lipid and carbohydrate content. Further chemical characterization was achieved by the advanced analytical technique of multinuclear and multidimensional NMR spectroscopy. NMR spectroscopy revealed the scarcity of lipids which preferentially resulted of alcoholic origin, or otherwise hydroxylate and several aminoacids (valine, leucine and alanine) in the aqueous extract in relation to the protein nature of M. infundibulum mucus. The mucus indeed is mainly composed by water (94% &plusmn, 0.7%) whereas its dry weight is made of proteins (36% &plusmn, 2.3%) followed by lipids (2.9% &plusmn, 0.07%) and carbohydrates (2% &plusmn, 0.31%). The mucus exerted a natural antibacterial lysozyme-like activity corresponding to 1.14 mg mL&minus, 1 of hen egg-white lysozyme and an antioxidant activity corresponding to 483.00 &plusmn, 79.22 nmolTE (Trolox equivalent)/mL sample as Trolox Equivalent Antioxidant Capacity (TEAC) and 276.26 &plusmn, 50.76 nmolTE/mL sample as Oxygen Radical Absorbance Capacity (ORAC). Therefore, our findings have potential implications due to the ongoing explosion of antibiotic resistant infections and the need to discover antibacterial agents. Additionally, the observed antioxidant activity is intriguing taking into account the need to find natural antioxidants useful for human health.

Recent studies have shown that marine algae represent a great source of natural compounds with several properties. The lipidic extract of the seaweed Chaetomorpha linum (Chlorophyta, Cladophorales), one of the dominant species in the Mar Piccolo of Taranto (Mediterranean, Ionian Sea), revealed an antibacterial activity against Vibrio ordalii and Vibrio vulnificus, common pathogens in aquaculture, suggesting its potential employment to control fish and shellfish diseases due to vibriosis and to reduce the public health hazards related to antibiotic use in aquaculture. This extract showed also an antioxidant activity, corresponding to 170.960 &plusmn, 16. mmol Trolox equivalent/g (oxygen radical absorbance capacity assay&mdash, ORAC) and to 30.554 &plusmn, 2.30 mmol Trolox equivalent/g (Trolox equivalent antioxidant capacity assay&mdash, TEAC). The chemical characterization of the extract, performed by 1D and 2D NMR spectroscopy, highlighted the presence of free, saturated (SAFAs), unsaturated (UFAs) and polyunsaturated (PUFAs) fatty acids. The high content of &omega, 6 and &omega, 3 PUFAs confirmed also by gas chromatography indicates the potentiality of this algal species in the production of fortified food. The antibacterial activity seems related to the presence of linolenic acid present at high density, while the antioxidant activity could be likely ascribable to molecules such as carotenoids and chlorophylls (characterized also by thin-layer chromatography), known for this property. The presence of polyhydroxybutyrate, a biopolymer with potentiality in the field of biodegradable bioplastics was also detected. The exploitation of C. linum for a future biotechnological application is also encouraged by the results from a first attempt of cultivating this species in an integrated multi-trophic aquaculture (IMTA) system.

In this paper we compare the performance of the textured SnO2:F and Mo contacts with the p-type layer in p–i–n hydrogenate amorphous silicon (a-Si:H) solar cells. We use standard current–voltage (I–V) electrical characterization methods coupled with forward bias small signal impedance analysis. We show the efficacy of this technique to determine the effective carrier lifetime in photovoltaic cells. We show that such effective lifetimes are indeed directly connected to the respective dark diode saturation currents. We also find that the effective lifetime is constant with the temperature in the 0–70 °C range and it is significantly better for the solar cell with Mo diode contact. This also explains well the higher open circuit voltage Voc found under illumination in the Mo/p–i–n cell compared to the SnO2:F/p–i–n one.

Background: Iron overload and hepatitis C virus (HCV) infection together can lead to chronic liver damage in thalassemia major (TM) patients. Aims: We investigated viral, genetic, and disease factors influencing sustained virological response (SVR) after peg-interferon and ribavirin therapy in TM patients with HCV infection. Methods: We analyzed 230 TM patients with HCV infection (mean age 36.0 ± 6.3 years; 59.1% genotype 1; 32.2% genotype 2; 3.4% genotype 3; and 5.3% genotype 4; 28.7% carried CC allele of rs12979860 in IL28B locus; 79.6% had chronic hepatitis and 20.4% cirrhosis; 63.5% naive and 36.5% previously treated with interferon alone) treated in 14 Italian centers. Results: By multivariate regression analysis SVR was independently associated with CC allele of IL28B SNP (OR 2.98; CI 95% 1.29-6.86; p = 0.010) and rapid virologic response (OR 11.82; CI 95% 3.83-36.54; p < 0.001) in 136 genotype 1 patients. Combining favorable variables the probability of SVR ranged from 31% to 93%. In genotype 2 patients, only RVR (OR 8.61; CI 95% 2.85-26.01; p < 0.001) was associated with SVR higher than 80%. In 3 patients with cirrhosis a decompensation of liver or heart disease were observed. Over 50% of patients increased blood transfusions. Conclusion: Dual therapy in TM patients with chronic HCV infection is efficacious in patients with the best virological, genetic and clinical predictors. Patients with cirrhosis have an increased risk of worsening liver or heart disease.

Silicon quantum dots have been deposited on top of a 3-nm tunnel oxide by Low Pressure Chemical Vapour Deposition (LPCVD) and coated with a 7-nm Chemical Vapour Deposited (CVD) oxide. This stack was then incorporated in Metal-Oxide-Semiconductor structure and used as floating gate of a memory cell. The presence of 3 nm of tunnel oxides allows the injection of the charge by direct tunnel (DT) using low voltages for both program and erase operations. The charge stored in the quantum dots is able to produce a well-detectable flat band shift in the capacitors or, equivalently, a threshold voltage shift in the transistors. Furthermore, due to the presence of SiO 2 between the grains, the lateral charge loss is reduced and, thus, long retention time are possible. In this work we present good memory action characterised by low write voltages, write times of the order of milliseconds and long retention time in spite of the low tunnel oxide thickness. © 2002 Elsevier Science B.V. All rights reserved.

We have recently demonstrated that molybdenum ultra-thin films interposed between hydrogenated amorphous silicon (a-Si:H) and SnO2:F transparent conductive oxide (TCO) in thin film solar cells show light trapping effects which enhance the solar cells performances. The effect of this improvement may be attributed to surface plasmon polariton (SPP) modes excited at the molybdenum interface by the solar radiation. In this paper we show direct evidence of such SPP modes in the case of the molybdenum/air interface by using the attenuated total reflection (ATR) technique, pioneered by Kretschmann, and we evaluate the dielectric constant of molybdenum at 660 nm. (C) 2013 The Authors. Published by Elsevier Ltd.

Transfusion and iron chelation treatment have significantly reduced morbidity and improved survival of patients with thalassemia major. However, cardiac disease continues to be the most common cause of death. We report the left-ventricular ejection fraction, determined by echocardiography, in one hundred sixtyeight patients with thalassemia major followed for at least 5 years who received continuous monotherapy with deferoxamine (N = 108) or deferiprone (N = 60). The statistical analysis, using the generalized estimating equations model, indicated that the group treated with deferiprone had a significantly better left-ventricular ejection fraction than did those treated with deferoxamine (coefficient 0.97; 95% CI 0.37; 1.6, p = 0.002). The heart may be particularly sensitive to iron-induced mitochondrial damage because of the large number of mitochondria and its low level of antioxidants. Deferiprone, because of its lower molecular weight, might cross into heart mitochondria more efficiently, improving their activity and, thereby, myocardial cell function. Our findings indicate that the long-term administration of deferiprone significantly enhances left-ventricular function over time in comparison with deferoxamine treatment. However, because of limitations related to the design of this study, these findings should be confirmed in a prospective, randomized clinical trial.

We report on the improvement of short circuit current (JSC), fill factor (FF), and open circuit resistance (ROC) in hydrogenated amorphous silicon (a-Si:H) photovoltaic cells with a p-type/intrinsic/n-type structure, achieved by the addition of an ultra-thin molybdenum film between the p-type film and the transparent conductive oxide/glass substrate. For suitable conditions, improvements of ≈10% in average internal quantum efficiency and up to 5%–10% under standard illumination in JSC, FF, and ROC are observed. These are attributed to the excitation of surface plasmon polariton modes of the a-Si:H/Mo interface.

The induced changes of the flatband voltage by the location of holes in a silicon-rich oxide (SRO) film sandwiched between two thin SiO 2 layers [used as gate dielectric in a metal-oxide-semiconductor (MOS) capacitor] can be used as the two states of a memory cell. The principle of operation is based on holes permanently trapped in the SRO layer and reversibly moved up and down, close to the metal and the semiconductor, in order to obtain the two logic states of the memory. The concept has been verified by suitable experiments on MOS structures. The device exhibits an excellent endurance behavior and, due to the low mobility of the holes at low field in the SRO layer, a much longer refresh time compared to conventional dynamic random access memory cells. © 2002 American Institute of Physics.

In β-thalassemia major (β-TM) patients, iron chelation therapy is mandatory to reduce iron overload secondary to transfusions. Recommended first line treatment is deferoxamine (DFO) from the age of 2 and second line treatment after the age of 6 is deferiprone (L1). A multicenter randomized open-label trial was designed to assess the effectiveness of long-term alternating sequential L1-DFO versus L1 alone iron chelation therapy in β-TM patients. Deferiprone 75 mg/kg 4 days/week and DFO 50 mg/kg/day for 3 days/week was compared with L1 alone 75 mg/kg 7 days/week during 5-year follow-up. A total of 213 thalassemia patients were randomized and underwent intention-to-treat analysis. Statistically, a decrease of serum ferritin levels was significantly higher in alternating sequential L1-DFO patients compared with L1 alone patients (p = 0.005). Kaplan-Meier survival analysis for the two chelation treatments did not show statistically significant differences (log-rank test, p = 0.3145). Adverse events and costs were comparable between the groups. Alternating sequential L1-DFO treatment decreased serum ferritin concentration during a 5-year treatment by comparison to L1 alone, without significant differences of survival, adverse events or costs. These findings were confirmed in a further 21-month follow-up. These data suggest that alternating sequential L1-DFO treatment may be useful for some β-TM patients who may not be able to receive other forms of chelation treatment.

A multicentre randomized open-label trial was designed to assess the effectiveness of long-term sequential deferiprone–deferoxamine (DFO–DFP) versus DFP alone to treat thalassaemia major (TM). DFP at 75 mg/kg, divided into three oral daily doses, for 4 d/week and DFO by subcutaneous infusion (8–12 h) at 50 mg/kg per day for the remaining 3 d/week was compared with DFP alone at 75 mg/kg, administered 7 d/week during a 5-year follow-up. The main outcome measures were differences between multiple observations of serum ferritin concentrations. Secondary outcomes were survival analysis, adverse events, and costs. Consecutive thalassaemia patients (275) were assessed for eligibility; 213 of these were randomized and underwent intention-to-treat analysis. The decrease of serum ferritin levels during the treatment period was statistically significant higher in sequential DFP–DFO patients compared with DFP-alone patients (P = 0.005). Kaplan– Meier survival analysis for the two chelation treatments did not show any statistically significant differences (log-rank test, P = 0.3145). Adverse events and costs were comparable between the groups. The trial results show that sequential DFP–DFO treatment compared with DFP alone significantly decreased serum ferritin concentration during treatment for 5 years without significant differences regarding survival, adverse events, or costs.

The prognosis for thalassemia major has dramatically improved in the last two decades. However, many transfusion-dependent patients continue to develop progressive accumulation of iron. This can lead to tissue damage and eventually death, particularly from cardiac disease. Previous studies that investigated iron chelation treatments, including retrospective and prospective non-randomised clinical trials, suggested that mortality, due mainly to cardiac damage, was reduced or completely absent in patients treated with deferiprone (DFP) alone or a combined deferiprone-deferoxamine (DFP-DFO) chelation treatment. However, no survival analysis has been reported for a long-term randomised control trial. Here, we performed a multicenter, long-term, randomised control trial that compared deferoxamine (DFO) versus DFP alone, sequential DFP-DFO, or combined DFP-DFO iron chelation treatments. The trial included 265 patients with thalassemia major, with 128 (48.3%) females and 137 (51.7%) males. No deaths occurred with the DFP-alone or the combined DFP-DFO treatments. One death occurred due to graft versus host disease (GVHD) in a patient that had undergone bone marrow transplantation; this patient was censored at the time of transplant. Only one death occurred with the DFP-DFO sequential treatment in a patient that had experienced an episode of heart failure one year earlier. Ten deaths occurred with the deferoxamine treatment. The main factors that correlated with an increase in the hazard ratio for death were: cirrhosis, arrhythmia, previous episode of heart failure, diabetes, hypogonadism, and hypothyroidism. In a Cox regression model, the interaction effect of sex and age was statistically significant (p-value

In this paper we studied program/erase characteristics by FN tunneling in Si nanocrystal memories. Starting from a very good agreement between experimental data and simulations in the case of a memory cell with a thin tunnel oxide, Silicon dots as medium for charge storage, and a CVD silicon dioxide used as control dielectric, we present estimated values of the charge trapping when a high-k material is present in the control dielectric. We then show preliminary results of nanocrystal memories with control dielectric containing high-k materials. ©2004 IEEE.

We have realized Si nanocrystal memory cells in which the Si dots have been deposited by CVD on SiO2 and then covered by a CVD control oxide. In this paper, we report a study on the potential of these cells for dual bit storage. © 2004 Elsevier B.V. All rights reserved.

We have realized Si nanocrystal memory cells in which the Si dots have been deposited by chemical vapor deposition (CVD) on the tunnel oxide and then covered by a CVD control oxide. In this paper we report a study on the potential of this type of cells for multi-bit storage. In particular, the possibilities offered by these devices from the point of view of program/erase mechanisms, endurance, and charge retention are shown and discussed.

Nanocrystal memory cell are a promising candidate for the scaling of nonvolatile memories in which the conventional floating gate is replaced by an array of nanocrystals. The aim of this paper is to present the results of a thorough investigation of the possibilities and the limitations of such new memory cell. In particular, we focus on devices characterized by a very thin tunnel oxide layer and by silicon nanocrystals formed by chemical vapor deposition. The direct tunneling of the electrons through the tunnel oxide, their storage into the silicon nanocrystals, and furthermore, retention, endurance, and drain turn-on effects, well-known issues for nonvolatile memories, are all investigated. The cell can be also programmed by channel hot electron injection, allowing the possibility to multibit storage. The suppression of the drain turn-on and the possibility of using this cell for multibit storage give us a clear evidence of the distributed nature of the charge storage.

A multicenter randomized open-label long-term sequential deferiprone–deferoxamine (DFP-DFO) versus DFP alone trial (sequential DFP-DFO) performed in patients with thalassemia major (TM) was retrospectively reanalyzed to assess the variation in the left ventricular ejection fraction (LVEF) [1].

Structural properties of silicon rich oxide films (SRO) have been investigated by means of micro-Raman spectroscopy and transmission electron microscopy (TEM). The layers were deposited by plasma enhanced chemical vapor deposition using different SiH4/O2 gas mixtures. The Raman spectra of the as-deposited SRO films are dominated by a broad band in the region 400-500 cm-1 typical of a highly disordered silicon network. After annealing at temperatures above 1000°C in N2, the formation of silicon nanocrystals is observed both in the Raman spectra and in the TEM images. However, most of the precipitated silicon does not crystallize and assumes an amorphous microstructure. © 2002 The Electrochemical Society. All rights reserved.

We have realized nanocrystal memories by using silicon quantum dots embedded in silicon dioxide. The Si dots with the size of few nanometers have been obtained by chemical vapor deposition on very thin tunnel oxides and subsequently coated with a deposited SiO2 control dielectric. A range of temperatures in which we can adequately control a nucleation process, that gives rise to nanocrystal densities of ∼3×1011 cm−2 with good uniformity on the wafer, has been defined. The memory effects are observed in metal-oxide-semiconductor capacitors or field effect transistors by significant and reversible flat band or threshold voltage shifts between written and erased states that can be achieved by applying gate voltages as low as 5 V. The program-erase window does not exhibit any change after 105 cycles on large area cells showing that the endurance of such a memory device which uses a thinner tunnel oxide is potentially much higher than that of standard nonvolatile memories. Moreover, good retention results are ...

To form crystalline Si dots embedded in SiO2, we have deposited thin films of silicon-rich oxide (SRO) by plasma-enhanced chemical vapor deposition of SiH4 and O2. Then the materials have been annealed in N2 ambient at temperatures between 950°C and 1100°C. Under such processing, the supersaturation of Si in the amorphous SRO film produces the formation of crystalline Si dots embedded in SiO2. The narrow dot size distributions, analyzed by transmission electron microscopy, are characterized by average grain radii and standard deviations down to about 1 nm. The memory functions of such structures has been investigated in MOS capacitors with a SRO film sandwiched between two thin SiO2 layers as insulator and with an n+ polycrystalline silicon gate. The operations of write and storage are clearly detected by measurements of hysteresis in capacitance-voltage characteristics. A model which explains both the occurence of steady-state conduction through the SiO2/SRO/SiO2 stack at a relatively low voltage and the shift of flat-band voltage is presented and discussed. © 2001 Elsevier Science B.V. All rights reserved.

Metal-oxide-semiconductor capacitors in which the gate oxide has been replaced with a silicon rich oxide (SRO) film sandwiched between two thin SiO2 layers are presented and investigated by transmission electron microscopy and electrical measurements. The grain size distribution and the amount of crystallized silicon remaining in SRO after annealing have been studied by transmission electron microscopy, whereas the charge trapping and the charge transport through the dots in the SRO layer have been extensively investigated by electrical measurements. Furthermore, a model, which explains the electrical behavior of such SRO capacitors, is presented and discussed. © 2001 American Institute of Physics.

We have compared the thermal damage in ultrathin gate SiO2 layers of 5.6 and 3 nm thickness after intrinsic dielectric breakdown due to constant voltage Fowler-Nordheim stress. The power dissipated through the metal-oxide-semiconductor capacitor during the breakdown transient, measured with high time resolution, strongly decreases with oxide thickness. This is reflected in a noticeable reduction of the thermal damage found in the structure after breakdown. The effect can be explained as the consequence of the lower amount of defects present in the oxide at the breakdown instant and of the occurrence of a softer breakdown in the initial spot. The present data allow us to estimate the power threshold at the boundary between soft and hard breakdown, and they are compared to numerical simulations of heat flow. © 2001 American Institute of Physics.

An in vitro culture of Alkanna tinctoria Tausch cells was set up in order to investigate the possibility of producing alkannin, a red naphthoquinone naturally present in the root bark of this plant. Furthermore, an in vitro culture of callusderived roots was established and the production of alkannin evaluated. In the different experimental conditions investigated, differences in the production of alkannin derivatives as well as in the type of pigments produced, were observed. The potential use of this technology is discussed.

We report for the first time on the metalorganic vapour phase epitaxy of ZnS layers on (100)GaAs substrates by using tertiary-butyl-mercaptan ((t-Bu)SH) and dimethylzinc:triethylamine adduct (Me(2)Zn:Et(3)N) as sulphur and zinc precursors, respectively. We demonstrate that the combination of Me(2)Zn:Et(3)N with (t-Bu)SH avoids the occurrence of pre-reactions even under atmospheric pressure conditions, allowing the growth of good quality single crystalline ZnS epitaxial layers. However, low pressures (ca. 300 mbar) were necessary to limit the gas phase depletion of the precursors in the reactor chamber, a consequence of the low thermal stability of (t-Bu)SH and Me(2)Zn:Et(3)N. ZnS growth rates as high as 2.4 µm/h were thus obtained at around 346°C, the growth process being kinetically limited at lower temperatures. The surface of the epilayers was invariably smooth and mirror-like, its average surface roughness being typically around a few nanometers. Finally, no apparent diffusion of Zn and S into the GaAs substrate was observed for samples grown at 350°C, whereas Ga and As were detected into regions of the ZnS epilayers close to the ZnS/GaAs heterointerface.

To form crystalline Si dots embedded in SiO2, we have deposited thin films of silicon rich oxide (SRO) by plasma-enhanced chemical vapor deposition of SiH4 and O2. Then the materials wereannealed in N2 ambient at temperatures between 950 and 1100 °C. Under such processing, the supersaturation of Si in the amorphous SRO film produces the formation of crystalline Si dots embedded in SiO2. The narrow dot size distributions, analyzed by transmission electron microscopy, are characterized by average grain radii and standard deviations down to about 1 nm. The memory function of such structures has been investigated in metal-oxidesemiconductor (MOS) capacitors with a SRO film sandwiched between two thin SiO2 layers as insulator and with an n+ polycrystalline silicon gate. The operations of write and storage are clearly detected by measurements of hysteresis in capacitance-voltage characteristics and they have been studied as a function of bias.

For the first time, memory devices with optimized high density (2E12#/cm/sup 2/) LPCVD Si nanocrystals have been reproducibly achieved and studied on an extensive statistical basis (from single cell up to 1 Mb test-array) under different programming conditions. An original experimental and theoretical analysis of the threshold voltage shift distribution shows that Si nanocrystals have serious potential to push the scaling of NOR and NAND flash at least to the 35 nm and 65 nm nodes, respectively.

By electrical measurements we investigate the charge trapping and the charge transport in MOS capacitors in which the gate oxide has been replaced with a silicon rich oxide (SRO) film sandwiched between two thin SiO2 layers.