Preparation of Remote Plasma Atomic Layer-Deposited HfO2 Thin Films with High Charge Trapping Densities and Their Application in Nonvolatile Memory Devices.

Optimization of equipment structure and process conditions is essential to obtain thin films with the required properties, such as film thickness, trapped charge density, leakage current, and memory characteristics, that ensure reliability of the corresponding device. In this study, we fabricated metal-insulator-semiconductor (MIS) structure capacitors using HfO2 thin films separately deposited by remote plasma (RP) atomic layer deposition (ALD) and direct-plasma (DP) ALD and determined the optimal process temperature by measuring the leakage current and breakdown strength as functions of process temperature. Additionally, we analyzed the effects of the plasma application method on the charge trapping properties of HfO2 thin films and properties of the interface between Si and HfO2. Subsequently, we synthesized charge-trapping memory (CTM) devices utilizing the deposited thin films as charge-trapping layers (CTLs) and evaluated their memory properties. The results indicated excellent memory window characteristics of the RP-HfO2 MIS capacitors compared to those of the DP-HfO2 MIS capacitors. Moreover, the memory characteristics of the RP-HfO2 CTM devices were outstanding as compared to those of the DP-HfO2 CTM devices. In conclusion, the methodology proposed herein can be useful for future implementations of multiple levels of charge-storage nonvolatile memories or synaptic devices that require many states.

A Survey on Air-Gap Attacks: Fundamentals, Transport Means, Attack Scenarios and Challenges.

Major public institutions and organizations that handle sensitive data frequently enforce strong security policies by implementing network separation policies that segregates their internal work networks and internet network using air gaps to prevent the leakage of confidential information. Such closed networks have long been considered the most secure technique for protecting data; however, studies have shown that they are no longer effective in providing a safe data protection environment. Research on air-gap attacks remains in its infancy stage. Studies have been conducted to check the method and demonstrate the possibility of transmitting data using various transmission media available within the closed network. These transmission media include optical signals such as HDD LEDs, acoustic signals such as speakers, and the electrical signals of power lines. This paper examines various media used for air-gap attacks by analyzing different techniques and their essential functions, strengths, and limitations. The findings of this survey and the follow-up analysis aim to assist companies and organizations in protecting their information by providing an understanding of air-gap attacks and their current trends.

Effect of Process Temperature on Density and Electrical Characteristics of Hf0.5Zr0.5O2 Thin Films Prepared by Plasma-Enhanced Atomic Layer Deposition.

HfxZr1-xO2 (HZO) thin films have excellent potential for application in various devices, including ferroelectric transistors and semiconductor memories. However, such applications are hindered by the low remanent polarization (Pr) and fatigue endurance of these films. To overcome these limitations, in this study, HZO thin films were fabricated via plasma-enhanced atomic layer deposition (PEALD), and the effects of the deposition and post-annealing temperatures on the density, crystallinity, and electrical properties of the thin films were analyzed. The thin films obtained via PEALD were characterized using cross-sectional transmission electron microscopy images and energy-dispersive spectroscopy analysis. An HZO thin film deposited at 180 °C exhibited the highest o-phase proportion as well as the highest density. By contrast, mixed secondary phases were observed in a thin film deposited at 280 °C. Furthermore, a post-annealing temperature of 600 °C yielded the highest thin film density, and the highest 2Pr value and fatigue endurance were obtained for the film deposited at 180 °C and post-annealed at 600 °C. In addition, we developed three different methods to further enhance the density of the films. Consequently, an enhanced maximum density and exceptional fatigue endurance of 2.5 × 107 cycles were obtained.

Body mass index category as a risk factor for colorectal adenomas: a systematic review and meta-analysis.

OBJECTIVES: The association between increasing body weight and colorectal adenoma prevalence has been suggested to follow a similar pattern to excess weight and colorectal cancer, although the magnitude of this relationship has not been validated. The objective of this study was to quantify the association and dose-response relationship between body mass index (BMI) and colorectal adenoma prevalence in clinical trials. METHODS: We systematically reviewed 23 studies (168,201 participants), which compared the prevalence of colorectal adenomas according to World Health Organization BMI categories. We assessed the effects of each BMI category on colorectal adenomas where odds ratio (OR) was used as a surrogate for effect size, and applied multivariate meta-analysis as a method of sensitivity analysis to evaluate the robustness of our findings and to analyze adenoma prevalence by multiple BMI categories simultaneously to assess for a dose-response relationship. Heterogeneity and publication bias were assessed. RESULTS: Subjects with a BMI of ≥25 had a significantly higher prevalence of colorectal adenomas (OR=1.24 (95% confidence interval (CI): 1.16-1.33), P<0.01) when compared with those with BMI<25. Multivariate meta-analysis also confirmed a positive association between higher BMI categories and the prevalence of colorectal adenoma (BMI: 25-30 vs. BMI<25; OR=1.21 (95% CI: 1.07-1.38), P<0.01; BMI≥30 vs. BMI<25; OR=1.32 (95% CI: 1.18-1.48), P<0.01) and revealed a dose-response relationship. CONCLUSIONS: The positive association between obesity and colorectal adenoma prevalence demonstrates an underlying dose-response relationship according to BMI. Colorectal centers may benefit from the timely screening of obese patients for colorectal adenomas in addition to clarifying the biological role of adiposity on colorectal tumor initiation and progression.

Successful treatment of an iatrogenic giant femoral artery pseudoaneurysm with percutaneous thrombin injection.

A femoral artery pseudoaneurysm (FAP) is one of the most troublesome complications following invasive procedures related to the femoral arterial access. Post-procedure FAP rarely occurs; however, its occurrence tends to increase with the more frequently antiplatelet agents, anticoagulants, and larger-sized catheter used for interventional procedures. Traditionally, surgical repair has been considered as the standard treatment modality for FAP; however, less invasive methods currently exist such as blind manual or ultrasound-guided compression repair (UGCR) as well as percutaneous thrombin injection, both of which have replaced the need for surgery. We report a case of a giant pseudoaneurysm in a femoral artery, which had developed as a complication of stenting in a patient with carotid artery stenosis and ischemic heart disease, and was subsequently successfully treated using percutaneous thrombin injection.