[PDF]    http://dx.doi.org/10.3952/lithjphys.44410

Open access article / Atviros prieigos straipsnis

Lith. J. Phys. 44, 303–309 (2004)


SIMULATION OF Si AND SiO2 ETCHING IN CF4 + H2 PLASMA
R. Knizikevičius
Department of Physics, Kaunas University of Technology, K. Donelaičio 73, LT-44029 Kaunas, Lithuania
E-mail: Rimantas.Knizikevicius@ktu.lt

Received 1 February 2004

The reactive ion etching of silicon and silicon oxide in CF4 + H2 plasma is considered by the proposed model, which includes processes of adsorption, chemical reactions, desorption, sputtering, and stochastic mixing. The etching rates are calculated as functions of concentrations of chemically active and inactive plasma components and ion bombardment parameters. The chemical composition of CF4 + H2 plasma is calculated to achieve the goal. It is found that the reaction products and CF2 radicals cover the silicon surface. CF2 radicals penetrate in the bulk and form an altered layer in the near-surface region. At high H2 content in the feed (>30%), the deposition of fluorocarbon polymer takes place. Meanwhile, the concentrations of adsorbed layer components are low during SiO2 etching in CF4 + H2 plasma.
Keywords: CF4 + H2 plasma, Si, SiO2, reactive ion etching
PACS: 52.77.Bn, 82.33.Pt


Si IR SiO2 ĖSDINIMO CF4 + H2 PLAZMOJE MODELIAVIMAS
R. Knizikevičius
Kauno technologijos universitetas, Kaunas, Lietuva

Išnagrinėtas silicio ir silicio oksido reaktyvus joninis ėsdinimas CF4 + H2 plazmoje. Pasiūlytame modelyje atsižvelgta į įgerties, cheminių reakcijų, atvirkštinės gerties, dulkėjimo ir stochastinio maišymo vyksmus. Ėsdinimo spartos vertės apskaičiuotos kaip chemiškai aktyvių ir neaktyvių plazmos sandų koncentracijų bei joninio apšaudymo parametrų funkcija. Tikslui pasiekti apskaičiuota CF4 + H2 plazmos cheminė sudėtis. Rasta, kad reakcijos produktai ir CF2 radikalai dengia silicio paviršių. CF2 radikalai prasiskverbia į tūrį ir sudaro pakeistą sluoksnį. Esant dideliam H2 kiekiui įleidžiamame mišinyje (>30%), susidaro fluorokarboninis polimeras. Tačiau silicio oksido ėsdinimo CF4 + H2 plazmoje metu įgerto sluoksnio sandų koncentracijos yra mažos.


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