Synthesis, Properties and Aging of ICP-CVD SiCxNy:H Films Formed from Tetramethyldisilazane

Amorphous hydrogenated silicon carbonitride films were synthesized on Si(100), Ge(111), and fused silica substrates using the inductively coupled plasma chemical vapor deposition technique. 1,1,3,3-tetramethyldisilazane (TMDSN) was used as a single-source precursor. The effect of the precursor’s pressure in the initial gas mixture, the substrate temperature, the plasma power, and the flow rate of nitrogen gas as an additional reagent on the film growth rate, element composition, chemical bonding, wettability of film surface, and the optical and mechanical properties of a-SiCxNy:H films was investigated. In situ diagnostic studies of the gas phase have been performed by optical emission spectroscopy during the film deposition process. The long-term stability of films was studied over a period of 375 days. Fourier-transform infrared (FTIR) and X-ray energy dispersive spectroscopy (EDX), and wettability measurements elucidated the oxidation of the SiCxNy:H films deposited using TMDSN + N2 mixture. Films obtained from a mixture with argon had high stability and maintained the stability of element composition after long-term storage in ambient air.

Electrical Characteristics and Reliability of SiCN/ Porous SiOCH Stacked Dielectric: Effects of Deposition Temperature of SiCN Film

Silicon carbonitride (SiCN) films deposited using silazane singe-precursor with different temperatures were capped onto porous carbon-doped silicon oxide (p-SiOCH) dielectric films. Effects on the electrical and reliability characteristics of the fabricated SiCN/p-SiOCH stacked dielectrics were investigated. Experimental results indicated that increasing the deposition temperature of the SiCN film increased barrier capacity against Cu migration under thermal and electrical stress and time-dependence-dielectric-breakdown reliability for the SiCN/p-SiOCH stacked dielectric. Therefore, this study provides a promising processing to deposit a SiCN barrier by elevating the deposition temperature and using N-methyl-aza-2,2,4-trimethylsilacyclopentane singe-precursor, which can be applied to back-end-of-line interconnects for advanced technological nodes in the semiconductor industry. A larger capacitance, however, is the main issue due to a larger intrinsic dielectric constant of the SiCN film and stronger plasma-induced damage on the p-SiOCH film. As a result, the related actions will be taken in the future research to improve this issue.

Crosslinking Behavior of UV-Cured Polyorganosilazane as Polymer-Derived Ceramic Precursor in Ambient and Nitrogen Atmosphere

Polymer-derived ceramics (PDCs) based on silicon precursor represent an outstanding material for ceramic coatings thanks to their extraordinary versatile processibility. A promising example of a silicone precursor, polyorganosilazane (Durazane 1800), was studied concerning its crosslinking behavior by mixing it with three different photoinitiators, and curing it by two different UV-LED sources under both nitrogen and ambient atmosphere. The chemical conversion during polymerization and pyrolysis was monitored by FTIR spectroscopy. Pyrolysis was performed in a nitrogen atmosphere at 950 °C. The results demonstrate that polyorganosilazane can be cured by the energy-efficient UV-LED source at room temperature in nitrogen and ambient atmosphere. In nitrogen atmosphere, already common reactions for polysilazanes, including polyaddition of the vinyl group, dehydrogenation reactions, hydrosilylation, and transamination reaction, are responsible for crosslinking. Meanwhile, in ambient atmosphere, hydrolysis and polycondensation reactions occur next to the aforementioned reactions. In addition, the type of photoinitiator has an influence on the conversion of the reactive bonds and the chemical composition of the resulting ceramic. Furthermore, thermogravimetric analysis (TGA) was conducted in order to measure the ceramic yield of the cured samples as well as to study their decomposition. The ceramic yield was observed in the range of 72 to 78% depending on the composition and the curing atmosphere. The curing atmosphere significantly impacts the chemical composition of the resulting ceramics. Depending on the chosen atmosphere, either silicon carbonitride (SiCN) or a partially oxidized SiCN(O) can be produced.