Increased O(D1) metastable density in highly Ar-diluted oxygen plasmas

Abstract

Enhancement of the growth rate of SiO2 with a rare gas diluted O2 plasma is of interest for application to various microelectronics fabrications. The key is the oxygen metastable atom (D1) density, which has the potential for surface activation. We used vacuum ultraviolet optical absorption spectroscopy to detect O(D1) and found a twofold increase in the density of O(D1) due to the dilution with Ar. The density increase is reasonably explained by the increase of the electron density, the oxygen dissociation fraction, and the Ar metastable density, that are experimentally obtained for low O2 fractions.

Excitation Kinetics of Oxygen O(1D) State in Low-Pressure Oxygen Plasma and the Effect of Electron Energy Distribution Function

“…In addition, in Figure 4(b), we can find that the density of oxygen negative ion O -becomes larger than the electron density as lowering the reduced electric field as E/N = 90 Td, which also agrees with the general experimental results of low-pressure oxygen plasma [1,3]. However, in Figure 4(a) where the rate coefficient of reaction #12 is treated as the electron kinetic temperature T ek , we cannot find such tendency.…”

“…6 as a self-consistent one. When we examine Figure 4(a), it is found that the number density ratio of the atomic oxygen O( 1 D)/O( 3 P) 0.013 -0.014, which seems a little too low in comparison with Kitajima et al's report [3] or other similar works. On the other hand, when we calculate the rate coefficient with the self-consistent EEPF as was shown in eq.…”

“…[1,2]. In these advanced oxidation processes, several papers reported that the O( 1 D) atom, a metastable state of oxygen atom as the first excited state, should play a more essential role than O( 3 P), the ground state oxygen atom, to improve the electronic quality of the gate oxide films [3,4]. Although we also studied the excitation chemical kinetics of nitrogen/oxygen atoms and molecules in the low-pressure discharge nitrogenoxygen mixture plasma [5,6], we did not include the O( 1 D) state in our previous model [4], which should be definitely taken into account to the kinetic modeling for better understanding of the plasma oxidation processes for semiconductors.…”

Theoretical insight into Ar–O2surface-wave microwave discharges

“…Oxygen containing discharges and their afterglows have a wide range of applications due to the presence of active O( 3 P) and O( 1 D) atoms [1,2,3], excited O 2 (a 1 ∆ g ) molecules [4,5,6,7], and the ground-state O 2 (X 3 Σ − g ,v), which together with Ar + have been proven to be able to inactivate bacteria spores [8]. O 2 and Ar-O 2 plasmas have been successfully used for oxide films deposition [9,10], synthesis of metal oxide nanowires [11], sterilization and decontamination of medical instruments [1,12,13,14,15] and polymer surface treatment [3,16,17,18].…”

Influence of nitrogen impurities on the formation of active species in Ar-O2plasmas

“…They are thus interesting for several applications, for instance plasma sterilization [1][2][3][4][5], synthesis of nanowires [6,7], wool treatment [8], different surface treatment processes [9][10][11][12][13][14][15], damaging of cancer cells [16,17] or the iodineoxygen laser excitation [18][19][20][21]. We have recently conducted a thorough theoretical investigation on the formation of active species in these discharges [22,23], discussing in detail their main creation and destruction mechanisms and the conditions where they can be efficiently produced.…”