Physical and Electrical Analysis of Poly-Si Channel Effect on SONOS Flash Memory

In this study, polycrystalline silicon (poly-Si) is applied to silicon-oxide-nitride-oxide-silicon (SONOS) flash memory as a channel material and the physical and electrical characteristics are analyzed. The results show that the surface roughness of silicon nitride as charge trapping layer (CTL) is enlarged with the number of interface traps and the data retention properties are deteriorated in the device with underlying poly-Si channel which can be serious problem in gate-last 3D NAND flash memory architecture. To improve the memory performance, high pressure deuterium (D2) annealing is suggested as a low-temperature process and the program window and threshold voltage shift in data retention mode is compared before and after the D2 annealing. The suggested curing is found to be effective in improving the device reliability.

Process effect analysis on nitride trap distribution in silicon-oxide-nitride-oxide-silicon flash memory based on charge retention model

This paper analyzes data retention characteristics to determine process effects on the trap energy distribution of silicon nitride in silicon-oxide-nitride-oxide-silicon (SONOS) flash memory devices. Nitride films were prepared by low-pressure chemical vapor deposition (LPCVD) and plasma-enhanced chemical vapor deposition (PECVD). PEVCD films embedded with silicon nanocrystals (Si-NCs) were also compared. The flat band voltage shift in the programmed device was measured at high temperatures to observe the thermal excitation of electrons from the nitride traps in retention mode. The trap energy distribution was extracted using the charge decay rates, and the experimental results showed that nitride fabricated by PECVD has a shallower trap than nitride fabricated by LPCVD. In nitride with Si-NCs, increased trap sites were observed in the range of 1.14 eV to 1.24 eV.

Semi Analytical Modelling for Drain-Induced Barrier Lowering Reduction in Dual-Metal Gate all Around FET

In the research paper, the semi-analytical modelling is done for low drain-induced barrier lowering (DIBL) dual-metal gate all around FET (DM GAAFET). Vacuum and silicon nitride are considered in the act of the gate oxide material near drain region for dual-metal vacuum oxide gate all around FET (DM-VO GAAFET) and dual-metal nitride oxide gate all around FET (DM-NO GAAFET) respectively, in which surface potential, threshold voltage, and DIBL are modelled for both the devices. The proposed models are validated by comparing DM-NO GAAFET with DM-VO GAAFET. DM-NO GAAFET shows the better device performance than DM-VO GAAFET as the threshold voltage increased by 10% and DIBL decreased by 50% in simulated as well as analytical results. The obtained results are having very close agreement with simulated results for both the GAAFETs.

Performance Analysis of Dual Metal Nitride Oxide GAAFET based Common Source Amplifier

Gate all around FET (GAAFET) is a widely used device structure for designing analog and digital circuits. In this research paper, a common source amplifier is designed using a dual-metal nitride oxide gate all around FET (DM-NO GAAFET), and performance is investigated for gain, bandwidth, leakage power, and average power. Moreover, analytical expressions of potential, threshold voltage, and DIBL have also been given for DM-NO GAAFET. The DM-NO GAAFET based common source (CS) amplifier is compared with the MOSFET based CS amplifier to analyse the performance. First, RF performance parameters of total gate capacitance, unity gain frequency, and transit time are investigated for DM-NO GAAFET; consequently, look up table based Verilog A model is used to design CS amplifier. Since DM-NO GAAFET provides the very small value of miller capacitance which increases the maximum unity gain frequency of 2.340 THz at the gate voltage of 0.7V. The voltage gain of 2.51 at the frequency range of 10Hz to 50GHz for DM-NO GAAFET based CS amplifier, is observed which is 40.23 % higher as compared to MOSFET based CS amplifier. Furthermore, the higher bandwidth of 20GHz is also exhibited by DM-NO GAAFET based CS amplifier, which is advantageous for higher frequency applications. The leakage power and average power are reduced by 46.07% and 80.05%, respectively, for DM-NO GAAFET based CS amplifier, which makes it very much suitable for low power and higher frequency analog integrated circuits.

Nitride oxide synthase 3 and klotho gene polymorphisms in the pathogenesis of chronic kidney disease and age-related cognitive impairment: a systematic review and meta-analysis

Background: While it has been known that the development of chronic kidney disease (CKD) and age-related cognitive impairment involves several mediators, the evidence in clinical practice only reveals nitride oxide synthase (NOS) and klotho. However, the evidence for this topic is conflicted. The aim of this study was to assess the role of NOS and klotho single nucleotide polymorphisms (SNPs) in the pathogenesis of CKD and age-related cognitive impairment. Methods: We performed a meta-analysis during October to December 2019. Paper collection was performed in major scientific websites, and we extracted information of interest from each paper. Data were analyzed using a Z-test with either random or fixed effect model. Results: Our initial assessment identified NOS3 G894T, NOS3 T786C, NOS3 4b/4a, klotho (KL) G395A, and KL C1818T as the gene candidate for our meta-analysis. Our pooled calculation revealed that NOS3 G894T was associated with the risk of both age-related cognitive impairment and CKD. Increased susceptibility to age-related cognitive impairment was observed in the GG genotype, and increased risk of CKD was found in patients with a single T allele and TT genotype for NOS3 nucleotide 894. For NOS3 4b/4a, increased risk of CKD was only found in 4a4a genotype. For NOS3 T786C, we failed to show the association with both CKD and age-related cognitive impairment. Subsequently, for KL G395A, A allele and GA genotype were found to correlate with increased susceptibility to CKD, while its correlation to age-related cognitive impairment was failed to clarify. For KL C1818T, our analysis failed to find the correlation with the risk of CKD. Conclusions: Our results reveal that the NOS3 G894T gene polymorphism has a crucial role in the pathogenesis of both CKD and age-related cognitive impairment.