Detailed structural analysis and dielectric properties of silicon nitride film fabricated using pure nitrogen plasma generated near atmospheric pressure

Abstract

A detailed structural analysis and dielectric property measurements of silicon nitride films fabricated using atmospheric pressure (AP) plasma were carried out, and the results were compared to those of nitride films fabricated using a radio frequency plasma. Using AP plasma, 1.8-nm-thick silicon nitride films composed of Si3N3.5O0.7 were obtained at nitridation temperatures ranging from 25to500°C. X-ray photoelectron spectroscopy using a monochromatic AlKα source at 1486.6eV and high-resolution Rutherford backscattering spectrometry revealed approximately 10% more nitrogen atoms corresponding to the N–Si3 bond in the film using AP plasma than those using rf plasma. In the range of 25–500°C, the nitridation temperature did not affect the leakage current densities of the films fabricated using AP plasma. Films fabricated at 25°C showed leakage current density of as low as 7×10−2A∕cm2 at 5MV∕cm. This value was one order of magnitude lower than that using rf plasma. The direct-tunneling current simulation analysis with the Wentzel-Kramers-Brillouin approximation revealed that the effective tunneling mass of holes increased due to the nitrogen atoms incorporated in the films. From deep-level transient spectroscopy, signals attributed to defects generated by plasma irradiation in the silicon substrate were not observed.

Substoichiometric Silicon Nitride – An Anode Material for Li-ion Batteries Promising High Stability and High Capacity

“…A fixed chemical shift of 0.62 eV between the components and an increase of the full width at half maximum of 0.2 eV for increasing N content in the tetrahedron were found to give consistent results for all samples, with peak positions consistent with those reported by Hayakawa, et al . 40 . This fitting performed on the spectra obtained from the different a-SiN x thin films can be found in the supplementary information.…”

The comparison of the growth models of silicon nitride ultrathin films fabricated using atmospheric pressure plasma and radio frequency plasma

“…We also reported that the dielectric properties were regardless of the nitridation temperature. 12 This nitridation process regardless of the substrate temperature suggests that the activation energy of active nitrogen species required to react with Si at the nitridation temperature ranging from 25 to 500°C is negligibly small. 16,17 Figure 3 shows a time dependence of film thickness at elevated gas pressures of 50, 200, 500, and 700 Torr.…”

“…Their transitions correspond to N 2 second positive system ͑N 2 second ps: C 3 ⌸ u → B 3 ͚ g ͒ and N 2 Herman's infrared system ͑N 2 HIR: C 5 ⌸ g → A 5 ͚ u + ͒. 11,12 These molecular excited species were unique because atomic excited species are mainly observed in rf plasma. The nitridation and the dielectric properties of the silicon nitride films fabricated using AP plasma source were also reported elsewhere.…”

Orientation Control of ZnO Films Deposited Using Nonequilibrium Atmospheric Pressure N2/O2Plasma

“…We have reported that the N 2 second positive system (N 2 2ps) was predominantly observed in atmosphericpressure N 2 plasma and it retained a reactivity high enough to accomplish room-temperature nitridation of a silicon wafer. [21][22][23] There is quite a high potential energy state of above 10 eV from the ground state in the reaction process of N 2 2ps, 30) which can be expected to supply precursors a high energy to form highly 0001-oriented ZnO films. Therefore, we investigated the change in the optical emission spectra by varying the O 2 =ðO 2 þ N 2 Þ ratio systematically from an oxygen-rich gas composition to a nitrogen-rich gas composition.…”

“…Our research group has reported the room-temperature nitridation of Si [21][22][23] and Ge, 24) and dense SiO 2 can also be formed using AP N 2 plasma with a small amount of O 2 even in the downstream (remote) region. 25,26) Moreover, we have succeeded in the formation of ZnO films at a substrate temperature as low as 200 C using AP N 2 /O 2 plasma.…”