In this review of experimental studies, the retention time and endurance of memristor RRAM memory elements based on reversible resistive switching in oxide dielectrics are studied. The influence of external parameters—switching pulses and ambient temperature—as well as internal factors—evolution of the concentration of oxygen vacancies in the filament region, the material, structure; the thickness of the active dielectric layer, material of metal electrodes on the long-term stability of high resistance state (HRS) and the low resistance state (LRS) of the memristor is discussed.

Low temperature etching of organosilicate low-k dielectrics in CF3Br and CF4 plasmas is studied. The chemical composition of pristine and etched low-k films was measured by Fourier transform infrared spectroscopy. Reduction of plasma-induced damage at low process temperature is observed. It is shown that the plasma damage reduction is related to protective effects of accumulated reaction products (CHxFyBrz, SiBrx after CF3Br, and CFx polymers after CF4 plasma). The reaction products could then be removed by thermal annealing for the pores to become empty. In the case of CF4 plasma, the thickness of CFx polymer increases with the temperature reduction, which is measured by ellipsometry. This polymer layer leads to a strong decrease in the diffusion rate of fluorine atoms and, as a consequence, to reduction of plasma-induced damage. Bromine containing reaction products are less efficient for low-k surface protection against the plasma damage.

Surfactant-templated porous organosilicate glass low-k films have been deposited by using a tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) mixture with different ratios and Brij® 30 surfactant. The deposited films contain different concentrations of terminal methyl groups that are proportional to the MTEOS concentration. Increasing the methyl group concentration by changing the TEOS/MTEOS ratio decreases the open porosity, k-value, and Young's modulus and increases the mean pore radius, although the template concentration was kept constant. The plasma etch rate well correlates with the number of fluorine atoms penetrated into pores. Plasma damage by fluorine radicals depends on the carbon concentration in the films. It can be reduced by 60% when the carbon concentration in the films exceeds 10 at. % as measured by XPS (the films deposited with the TEOS/MTEOS ratio of 40/60). Damage to the dielectrics associated with exposure to vacuum ultraviolet photons is reduced by more than 70% for the same samples.

An in-depth experimental evaluation is presented of the Langmuir probe as a tool for monitoring the etching of polysilicon-gate MOS structures with an inductively coupled high-density plasma excited in a mixture of SF₆, O₂, and Ar. It is shown that Langmuir-probe measurements made in parallel with optical actinometry offer ways of accurate end-point detection and etch-rate monitoring. It is established that the surface reactions involved lead to considerable changes in major parameters of the charged plasma species in the course of the process, affecting both the densities of electrons and ions and the electron energy distribution function (EEDF). It is found that the effective electron temperature and EEDF of the working plasma differ greatly from those of an Ar plasma under the same excitation conditions. It is concluded that wafer-surface charging could be minimized by varying the electron temperature and energy distribution. On the basis of optical-actinometry measurements, relationships are identified between the fluorine-atom density in the bulk plasma and the etch rate of the polysilicon or the oxide, taking account of the influence of ion bombardment. A conception is put forward of how the etch selectivity could be controlled.

A pulsed Langmuir probe method of plasma diagnostics is proposed and validated for low-pressure, high-density, low-temperature plasmas capable of producing a nonconducting film on the probe surface. The method essentially involves cyclic probe-surface cleaning by ion bombardment. A switching pattern of probe potential is designed, taking into account the mechanism by which a space-charge region is formed near the probe. The method is successfully employed in an experiment on inductively coupled CHF₃ and Ar plasmas. The results of the experiment are presented.