Application of Si and SiO2 Etching Mechanisms in CF4/C4F8/Ar Inductively Coupled Plasmas for Nanoscale Patterns

Lee, Junmyung; Efremov, Alexander; Yeom, Geun Young; Lim, Nomin; Kwon, Kwang‐Ho

doi:10.1166/jnn.2015.11256

Cited by 29 publications

(68 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accordingly, there were many experimental studies (for example, Refs. [7][8][9][10][11][12][13][14][15][16][17] and earlier ones included in monographs [1][2][3][4]) reported on RIE kinetics and mechanisms for Si and SiO 2 in various fluorocarbon gas plasmas, including CF 4 -based gas mixtures. The most important findings may be summarized as follows:…”

Section: Introductionmentioning

confidence: 99%

“…(2) Both etching and polymerization kinetics may be effectively adjusted by mixing of fluorocarbon gas with Ar and/or O 2 [10,[13][14][15][16]. Corresponding mechanisms do work through changes in both gas-phase chemistry (formation/decay balance for F atoms and polymerizing radicals) [5,17] and heterogeneous processes kinetics (physical and chemical decomposition of the fluorocarbon polymer film) [14][15][16][17]. (3) The chemical interaction of F atoms with Si and SiO 2 exhibits different mechanisms and thus, may be controlled by different limiting stages.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dry Etching Performance and Gas-Phase Parameters of C6F12O + Ar Plasma in Comparison with CF4 + Ar

et al. 2021

Self Cite

View full text Add to dashboard Cite

This research work deals with the comparative study of C6F12O + Ar and CF4 + Ar gas chemistries in respect to Si and SiO2 reactive-ion etching processes in a low power regime. Despite uncertain applicability of C6F12O as the fluorine-containing etchant gas, it is interesting because of the liquid (at room temperature) nature and weaker environmental impact (lower global warming potential). The combination of several experimental techniques (double Langmuir probe, optical emission spectroscopy, X-ray photoelectron spectroscopy) allowed one (a) to compare performances of given gas systems in respect to the reactive-ion etching of Si and SiO2; and (b) to associate the features of corresponding etching kinetics with those for gas-phase plasma parameters. It was found that both gas systems exhibit (a) similar changes in ion energy flux and F atom flux with variations on input RF power and gas pressure; (b) quite close polymerization abilities; and (c) identical behaviors of Si and SiO2 etching rates, as determined by the neutral-flux-limited regime of ion-assisted chemical reaction. Principal features of C6F12O + Ar plasma are only lower absolute etching rates (mainly due to the lower density and flux of F atoms) as well as some limitations in SiO2/Si etching selectivity.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dry Etching Performance and Gas-Phase Parameters of C6F12O + Ar Plasma in Comparison with CF4 + Ar

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The general regularities and mechanisms which determine the gas-phase characteristics in the C4F8-based plasmas, including the C4F8+Ar gas system, were the subjects of detailed discussion in our previous works [15,18]. That is why, we will just briefly overview the corresponding data for an actual set of input parameters as well as focus the attention on the issues which have the principal importance for the purpose of this study.…”

Section: Resultsmentioning

confidence: 99%

PLASMA PARAMETERS, DENSITIES OF ACTIVE SPECIES AND ETCHING KINETICS IN C4F8+Ar GAS MIXTURE

Efremov

Murin

Kwon

2019

IVUZKKT

View full text Add to dashboard Cite

In this work, we performed the combined (experimental and model-based) study of gas-phase plasma characteristics and etching kinetics for both Si and SiO2 in the C4F8 + Ar gas mixture. The experiments were carried out at constant total gas pressure (p = 6 mTorr), input power (W = 900 W) and bias power (Wdc = 200 W) while the C4F8/Ar mixing ratio was varied in the range of 0–75% Ar. The data on internal plasma parameters, plasma chemistry as well as the steady-state plasma composition were obtained by both Langmuir probe diagnostics and 0-dimensional plasma modeling. The etching mechanisms were investigated through the analysis of relationships between the measured etching rates and the model-predicted fluxes of active species (F atoms, polymerizing CFx radicals and positive ions). It was found that, under the given set of experimental conditions, the Si and SiO2 etching process 1) appears in the steady-state etching regime; 2) exhibits the features of the ion-assisted chemical reactions in the neutral-flux-limited mode; and 3) is influenced by the fluorocarbon polymer film thickness. It was shown that the influence of input process parameters on the effective probability of chemical reaction between Si, SiO2 and fluorine atoms may be adequately characterized by the fluorocarbon radicals/fluorine atoms and fluorocarbon radicals/ion energy flux ratios.

show abstract

“…Plasma modeling was represented by 0-dimensional (global) kinetic model operated with volume-averaged plasma characteristics. Kinetic schemes (reaction sets with corresponding rate coefficients), modeling approaches and algorithm were taken from our previous works [15,16,18]. Input model parameters were experimental data on T e and J + .…”

Section: Experimental and Modeling Detailsmentioning

confidence: 99%

FEATURES OF SiO2 REACTIVE-ION ETCHING KINETICS IN CF4 + Ar + O2 AND C4F8 + Ar + O2 GAS MIXTURES

Efremov

Sobolev

2020

IVKKT

View full text Add to dashboard Cite

The effect of Ar/O2 mixing ratio on gas-phase characteristics and SiO2 etching kinetics in CF4 + Ar + O2 and C4F8 + Ar + O2 plasmas was studied under conditions of 13.56 MHz inductive RF discharge. The constant processing parameters were fraction of fluorocarbon component in a feed gas (50%) total gas pressure (6 mTorr), input power (700 W) and bias power (200 W). It was found that the full substitution of Ar for O2 in both gas systems results in non-monotonic (with a maximum at ~ 25% Ar + 25% O2) SiO2 etching rates as well as in monotonically increasing photoresist etching rate with higher absolute values for CF4-containing mixture. The steady-state densities of active species were determined using a combination of plasma diagnostics by Langmuir probes and 0-dimensional (global) plasma modeling. Corresponding results indicated that both gas systems are characterized by quite close parameters of electron and ion components while exhibit sufficient differences in the kinetics of neutral species, especially in the presence of O2. The latter produces opposite changes in F atom density as well as in effective probability of ion-assisted chemical reaction vs. Ar/O2 mixing ratio. Relationships between type of fluorocarbon component and heterogeneous process kinetics were analyzed through the set of gas-phase-related parameters (fluxes, flux-to-flux ratios) characterizing chemical etching pathways for SiO2 and formation/destruction balance for the fluorocarbon polymer film. It was suggested that the transition toward O2-rich plasma in the low-polymerizing CF4 + Ar + O2 plasma suppresses the effective probability for SiO2 + F reaction through decreasing efficiency for oxide bond breaking and desorption of etching products due to decreasing ion energy flux. Oppositely, an increase in O2 content in the high-polymerizing C4F8 + Ar + O2 mixture lifts up the effective reaction probability by decreasing fluorocarbon film thickness and providing better access of F atoms to the etched surface.

show abstract

Application of Si and SiO₂ Etching Mechanisms in CF₄/C₄F₈/Ar Inductively Coupled Plasmas for Nanoscale Patterns

Cited by 29 publications

References 28 publications

Dry Etching Performance and Gas-Phase Parameters of C6F12O + Ar Plasma in Comparison with CF4 + Ar

Dry Etching Performance and Gas-Phase Parameters of C6F12O + Ar Plasma in Comparison with CF4 + Ar

PLASMA PARAMETERS, DENSITIES OF ACTIVE SPECIES AND ETCHING KINETICS IN C4F8+Ar GAS MIXTURE

FEATURES OF SiO2 REACTIVE-ION ETCHING KINETICS IN CF4 + Ar + O2 AND C4F8 + Ar + O2 GAS MIXTURES

Contact Info

Product

Resources

About