Evolution Of Film Properties Research Articles

DC substrate bias enables preparation of superior-performance TiN electrode films over a wide process window

When stacking with various underlying layers in the microelectronics devices, titanium nitride electrode films are not only desired to meet the critical requirements for high conductivity and low surface roughness, but also to be deposited over a wide processing window. In this work, a negative substrate bias was introduced as an additional power for the reactive sputtering of titanium nitride films. Upon systematically adjusting the substrate bias, working pressure and substrate temperature, the evolution of film properties was studied in detail in terms of resistivity, growth rate, crystal structure, surface morphology and composition. It was shown that an optimized substrate bias is beneficial for film densification and grain reorientation. As a result, titanium nitride films with superior-performance (resistivity ≤ 53.2 μΩ·cm and surface roughness ≤0.66 nm) can be grown over a wide working pressure range of 0.3–1.1 Pa and substrate temperature range from room temperature to 350 °C.

DC reactively sputtered TiNx thin films for capacitor electrodes

Being used as typical electrode layers in the state-of-the-art microelectronic devices, titanium nitride (TiNx) thin films have to meet the critical requirements for high conductivity, low surface roughness and thickness. In this work, TiNx thin films were deposited by direct current (DC) reactive sputtering in a nitrogen and argon ambient using a titanium target. Upon systematically adjusting the sputtering current, target-substrate distance and deposition time, the evolution of film properties were investigated in detail in terms of the composition, crystalline structure, resistivity, thickness and surface roughness. At finally optimized deposition conditions, ultra-thin (∼ 10 nm) TiNx thin films with a low resistivity of 125 µΩ cm and small surface roughness of 0.297 nm can be obtained. These superior performances together with low-running cost suggest great promise for the TiNx thin films to be used as electrodes in microelectronic devices.

Properties evolution of phosphate film inhibitor as function of immersion time

Inhibitory properties of three chemical products based on phosphate (Na3PO4, K2HPO4 and Na2PO3F) have been studied in synthetic concrete mediums contaminated by chlorides and then in reinforced concrete. Electrochemical measurements revealed that immersion of 7 d in 1 M K2HPO4 offered a maximum efficiency “75%”, while for Na3PO4 and Na2PO3F, 1 d of immersion in molar solution provides inhibitory efficiencies “70 and 67%”, respectively. Scanning electron microscopy tests performed on samples rinsed following the optimal duration, show that the film deposited on the surface varies for each tested product; so that the evolution of film properties is connected with electrical parameters which constituted the equivalent electrical circuit.