a high forming voltage may lead to current overshoot effect. [21,22] High power consumption is also a severe problem led by high forming voltage. Moreover, transistors which are connected to RRAM cells cannot endure such a high voltage and may cause problems of devices size scaling. Therefore, it is necessary to explore RRAM devices which have forming-free RS characteristic.There are many kinds of methods to deposit a forming-free film, and there are two kind of common types: One is by simply reducing the thickness of film or inserting a metal layer for reducing the overall insulation of the film, and make the forming voltage reduce to a very low level (approximate to the Set voltage); another is by using a substoichiometry film, because there are plenty of defects, the film will initially be in low resistance state (LRS). [15] But both of them are not perfect: the first one cannot ensure the position of generating defects thus the CCs have a random location and shape; the second one cannot ensure the quality of films and the initial defects are in a state of random distribution, the yield and reliability is not very good. Besides, in the present study of SiN x -based RRAM devices, due to the influence of preparation process (such as plasma enhanced chemical vapor deposition (PECVD)), there are always hydrogen atoms in the films. But unfortunately, the specific role of hydrogen atoms is still unclear and has some different kinds of comprehensions from scholars. [25][26][27] It will be better if we can exclude hydrogen atoms from the films. In this situa tion, we need a specific method that can solve all the questions above.In our previous work, we have investigated the effect of nitrogen-accommodation ability of electrodes in SiN x -based RS devices. [28] We found that tantalum has great nitrogenaccommodation ability to be the electrode. Besides, we have investigated the influence of nitrogen concentration on selfcompliance RS in Ta/SiN x /Pt RRAM devices and built a reliable RS model. [29] It seems that if we decrease the value of x, there will be more defects in the film. So in this work, we deposit SiN x films using RF sputtering to prevent the effect of hydrogen ions and fabricate forming-free RRAM devices with reliable switching stability successfully. To solve the problems of forming-free devices mentioned above, we try to improve the quality of films by increasing deposit temperature. But with the In this study, forming-free and reliable resistive switching characteristics are demonstrated by using Pt doping in a stacked structure of SiN x resistive random access memory cells. Pt nanoparticles are embedded in situ and the size of them are about 1-2 nm. It ensures the potential of size scaling for the devices. Compared to those without Pt doping, a more reliable switching stability with better endurance and retention characteristics is obtained. The operating voltages and currents are low so that it is suitable for low power consumption applications. Films deposited at higher temperature show better compact...

In this paper, the resistive switching phenomena in CMOS-compatible Ta/ SiN x /Pt devices with different nitrogen concentrations are investigated. The SiN x resistance random-access memory (RRAM) devices show self-compliance RS characteristics with low operation voltage. This paper suggests that a dendric Si dangling-bond conductive channel and a nitrogen-rich SiN x layer formed at the Ta/SiN x interface are responsible for the self-compliance behavior. Lower operation current and energy consumption are achieved by increasing the nitrogen concentration of the SiN x films, which can be ascribed to increase of the band gap induced by the composition variation.

This letter studies the effect of the thickness of the top electrode on the performance of a SiNx resistive switching layer. We fabricated six devices with Ta electrodes of different thickness values (8 nm, 10 nm, 15 nm, 30 nm, 40 nm, and 50 nm) in a Ta/SiNx/Pt structure and then systematically investigated their performance. The high electrode thickness devices show stable and self-compliant bipolar resistive switching characteristics. In contrast, low electrode thickness devices display unstable RS behavior and have a high set voltage. In the low resistance state region, the Ta/SiNx/Pt devices obey Ohmic conduction, while in the high resistance state region, the conduction mechanism is Schottky emission. To explain the different RS behavior in the two device types, a nitrogen-ion-based model has been presented. According to this model, the device with a thicker top electrode has a stronger nitrogen accommodation ability, while the migration of nitrogen ions and silicon dangling bonds dominates conductive behavior.

Copper and iron play important roles in a variety of biological processes, especially when being chelated with proteins. The proteins involved in the metal binding, transporting and metabolism have aroused much interest. To facilitate the study on this topic, we constructed two databases (DCCP and DICP) containing the known copper- and iron-chelating proteins, which are freely available from the website http://sdbi.sdut.edu.cn/en. Users can conveniently search and browse all of the entries in the databases. Based on the two databases, bioinformatic analyses were performed, which provided some novel insights into metalloproteins.

The research deals with the overview of recent Unemployment insurance structure of Kazakhstan. It focuses on the theoretical of impact of UB payments on workers incentives to be employed and discuss its influences on Unemployment rate. Moreover provides overview of current situation regarding labor market of Kazakhstan.