A new simple method combining hot-wire CVD and pulsed liquid injection of metal-organic precursor solutions was developed for production of various chalcogenide films. The grown thin Ge2Sb2Te5 films exhibit electrically and optically induced reversible phase change behavior, showing the potential of deposition method for phase change memory applications.

The charge trapping properties of HfO2 thin films for application in charge trap memories are investigated as a function of high-temperature postdeposition annealing (PDA) and oxide thickness in the TaN/Al2O3/HfO2/SiO2/Si structure. The trap density (NT) in HfO2, extracted by simulating the programming transient, is in the 1019–1020 cm-3 range, and it is related to film thickness and PDA temperature. Diffusion phenomena in the stack play a significant role in modifying NT in HfO2 and the insulating properties of the Al2O3 layer. The memory performances for 1030 °C PDA are promising with respect to standard stacks featuring Si3N4.

A selective deposition process for bottom-up approach was developed in a modified plasma enhanced atomic layer deposition (PEALD) sequence. As a case study, a very standard PEALD TiO 2 using organo-amine precursor and O 2 plasma is chosen. The metal oxide selectivity is obtained on TiN versus Si-based surfaces by adding one etching/passivation plasma step of fluorine every n cycles in a PEALD-TiO 2 process. Fluorine gas NF 3 allows (1) to etch the TiO 2 layer on Si, SiO 2 , or SiN surface while keeping few nanometers of TiO 2 on the TiN substrate and (2) to increase the incubation time on the Si-based surface. Quasi-in situ XPS measurements were used to study the incubation time between Si/SiO 2 substrates versus TiN substrate. Results show that Si-F bonds are formed on Si and lock the surface reactions. The effectiveness of this atomic layer selective deposition method was successfully tested on a 3D patterned substrate with the metal oxide deposited only at the edge of metal lines.

The self-assembly of Ge(1)Sb(2)Te(4) nanowires (NWs) for phase change memories application was achieved by metal organic chemical vapor deposition, catalyzed by Au nanoislands in a narrow range of temperatures and deposition pressures. In the optimized conditions of 400 °C, 50 mbar, the NWs are Ge(1)Sb(2)Te(4) single hexagonal crystals. Phase change memory switching was reversibly induced by nanosecond current pulses through metal-contacted NWs with threshold voltage of about 1.35 V.

Er − doped HfO2 (Er∼15%) films are grown by atomic layer deposition on Si(100). The characteristics of the doped oxide are compared with those of HfO2. In Er−doped HfO2, the stabilization of the cubic structure, together with the effect of the high polarizability of Er3+, allow to obtain a dielectric constant of ∼33 after annealing at 900 °C. The insertion of Er within the metallic sublattice of HfO2 reduces the net density of fixed charges, due to the creation of oxygen vacancies. For similar equivalent oxide thickness, lower leakage currents are measured for Er−doped HfO2 than for HfO2.