Carbon content of silicon oxide films deposited by room temperature plasma enhanced chemical vapor deposition of hexamethyldisiloxane and oxygen

Abstract

Hexamethyldisiloxane is used as a silicon-source gas for plasma enhanced chemical vapor deposition (PECVD) growth of silicon oxide films for passivation layers in microelectronics. In order to produce low permeability films, it is necessary to minimize the carbon content. Films were deposited by a room temperature PECVD process in a parallel plate reactor, and were characterized by infrared spectroscopy, ellipsometry, microbalance, and elastic recoil detection (ERD). The infrared-active carbon groups appear in Si–CH3, CHx, C=O, and SiC bands. A double band at 2343 cm−1 has also been seen to track these bands. Deposition rate data shows linear behavior as a function of the Hexamethyldisiloxane (HMDSO) concentration in the reactor. The carbon within the films ranges from 36% to <1% of the amount of carbon assisted with HMDSO required to grow the films, depending upon the oxygen flow rate. By comparing the ERD composition data to the infrared spectral data, a carbon content correlation value has been found, and a detailed study of the data reveals evidence of C–C bond existence within films having the greatest total carbon content. Finally, it appears that the 2343 cm−1 band corresponds to CO2 rotational bands, in which the distribution of rotational states is evidence of hindered molecular motion.

Silicon‐based film on the yttria‐stabilized tetragonal zirconia polycrystal: Surface and shear bond strength analysis

“…The technique of PECVD, used in this study, is performed on materials susceptible to volatilization. They are inserted into the processing chamber, and undergo chemical reactions on the surface of the substrate to produce a non‐volatile solid that is deposited, forming a film . In contrast, the physical vapor deposition technique is characterized by the generation and transport of vapor from a source to the substrate, namely it functions by physical means.…”

“…During the growth of the film, a combination of chemicals is released into the chamber due to the presence of free accelerated ions, which then adhere to the substrate. Thus, besides the formation of the desired molecule, unwanted chemical bonds can also occur that interfere with the adhesion and surface energy of the film, for example, the C atom . The deposition parameters have a greater relevance in this technique.…”

“…They are inserted into the processing chamber, and undergo chemical reactions on the surface of the substrate to produce a non-volatile solid that is deposited, forming a film. 30 In contrast, the physical vapor deposition technique is characterized by the generation and transport of vapor from a source to the substrate, namely it functions by physical means. In the process, atoms are obtained by starting from a solid source, which is called the target, that are scattered in the direction of the substrate.…”

“…Thus, besides the formation of the desired molecule, unwanted chemical bonds can also occur that interfere with the adhesion and surface energy of the film, for example, the C atom. 30 The deposition parameters have a greater relevance in this technique. Thus, the plasma technique can be very sensitive, unlike sandblasting, which shows good results with a wide range of parameters and is already used in the literature.…”

Plasma enhanced chemical vapor deposition of nitrogen-incorporated silicon oxide films using TMOS/N2O gas

“…The results indicate that the number of Si-H bonds increases when the nitrogen content in the deposits is low. where the deposition rate depends linearly on the HMDSO concentration [10]. As can be seen, the refractive index lies between 1.43 and 1.53.…”