TiCl4 Barrier Process Engineering in Semiconductor Manufacturing
Titanium nitride (TiN) not only was utilized in the wear-resistant coatings industry but it was also adopted in barrier processes for semiconductor manufacturing. Barrier processes include the titanium (Ti) and TiN processes, which are commonly used as diffusion barriers in via/contact applications. However, engineers frequently struggle at the via/contact module in the beginning of every technology node. As devices shrink, barrier processes become more challenging to overcome the both the physical fill-in and electrical performance requirements of advanced small via/contact plugs. The aim of this paper is to investigate various chemical vapor deposition (CVD) TiCl4-based barrier processes to serve the application of advanced small via/contact plugs and the metal gate processes. The results demonstrate that the plasma-enhanced chemical vapor deposition (PECVD) TiCl4-based Ti process needs to select a feasible process temperature to avoid Si surface corrosion by high-temperature chloride flow. Conventional high step coverage (HSC) CVD TiCl4-based TiN processes give much better impurity performance than metal organic chemical vapor deposition (MOCVD) TiN. However, the higher chloride content in HSC film may degrade the long-term reliability of the device. Furthermore, it is evidenced that a sequential flow deposition (SFD) CVD TiCl4-based process with multiple cycles can give much less chloride content, resulting in faster erase speeds and lower erase levels than that of conventional HSC TiN.
Duplex Titanium Oxide Layers for Biomedical Applications
This article presented the results of Ti Grade 2 oxidation with the duplex/hybrid method, which combined fluidized bed atmospheric diffusive treatment (FADT) and treatment with plasma methods (PVD). The process was realized to form a titanium diffusive layer saturated with oxygen in the diffusion process and to produce a tight homogeneous oxide coating on Ti substrate, deposited with the magnetron spraying technique. The techniques applied made it possible to combine the synergetic effects of the layers generated and to reduce the stresses in the area of the PVD coating/oxidized Ti substrate interface. In addition, the processes influenced the decrease in the surface roughness parameter and the increase in substrate bio-compatibility, which resulted in easier hydroxyapatite clusters deposition. The diffusion process was realized in Al2O3 fluidized bed reactor, at 913 K for 8 h with air atmosphere, while the deposition of the oxide coatings was realized with magnetron sputtering, with the use of TiO2 target at a pressure of 3 × 10−2mbars. In order to assess the effects of Ti hybrid oxidation, microscopic (AFM, SEM, TEM-EFTEM), spectroscopic (GDOS), and X-ray tests (XRD, sin2Ψ) were performed. The coatings formed had structure, with a Tiα(O) diffusion zone and a TiO2 rutile and anatase oxide zone deposited on the substrate. It was concluded that hybrid method of duplex coatings formation (FADT + PVD) leads to reducing oxide layer defects after fluidized bed heat treatment and to generating a tight homogeneous layer with a favorable state of stress, which results in improving the bio-compatibility of the generated substrate, important from the biomedical applications point of view.
Formation of unexpected ions from a first-generation polyamidoamine dendrimer by use of methanol: an artefact due to electrospray emitter corrosion?
We report the formation of unexpected ions during the analyses of a first-generation polyamidoamine dendrimer in negative ion mode using an ion trap equipped with an electrospray ionisation source. These surprising ions corresponded to an increase of 12 m/z units over those expected. The formation of the unexpected ions was dependent on the tuning of the solution flow rate and the capillary high voltage. In addition, measurements of unusual value of the current suggested that a reaction was occurring in the corona plasma. The influence of methanol in this phenomenon was demonstrated by using CD(3)OH in the sample preparation. We propose two structures to explain the observed adduct based on the results of MS(2) experiments and by referring to previous work dealing with 12 m/z units addition. We showed that a corona discharge caused by alterations taking place to the electrospray capillary emitter was the origin of these unexpected ions. Finally, we discuss the mechanism involved in the formation of the ions and we propose means to control such artefacts.