Experimental investigations of electron density and ion energy distributions in dual-frequency capacitively coupled plasmas for Ar/CF4 and Ar/O2/CF4 discharges

The electron density and ion energy distribution (IED) are investigated in low-pressure dual-frequency capacitively coupled Ar/CF4 (90%/10%) and Ar/O2/CF4 (80%/10%/10%) plasmas. The relations between controllable parameters, such as high-frequency (HF) power, low-frequency (LF) power and gas pressure, and plasma parameters, such as electron density and IEDs, are studied in detail by utilizing a floating hairpin probe and an energy resolved quadrupole mass spectrometer, respectively. In our experiment, the electron density is mainly determined by the HF power and slightly influenced by the LF power. With increasing gas pressure, the electron density first goes up rapidly to a maximum value and then decreases at various HF and LF powers. The HF power also plays a considerable role in affecting the IEDs under certain conditions and the ion energy independently controlled by the LF source is discussed here. For clarity, some numerical results obtained from a two-dimensional fluid model are presented.

[1]  Fei Gao,et al.  Experimental and numerical investigations of electron density in low-pressure dual-frequency capacitively coupled oxygen discharges , 2013 .

[2]  Fei Gao,et al.  Measurements of ion energy distributions in a dual-frequency capacitively coupled plasma for Ar/O2 discharges , 2013 .

[3]  J. Benedikt,et al.  Quadrupole mass spectrometry of reactive plasmas , 2012 .

[4]  Zhi-Cheng Li,et al.  Experimental investigation of ion energy distributions in a dual frequency capacitively coupled Ar/CF4 plasma , 2010 .

[5]  D. Marić,et al.  Dual-frequency capacitive radiofrequency discharges: effect of low-frequency power on electron density and ion flux , 2010 .

[6]  Mark J. Kushner,et al.  Hybrid modelling of low temperature plasmas for fundamental investigations and equipment design , 2009 .

[7]  Zhi-Cheng Li,et al.  Numerical results for the Ar and CF4 mixture gas in a dual frequency capacitively coupled plasma using a hybrid model , 2009 .

[8]  V. Volynets,et al.  Study of fluorocarbon plasma in 60 and 100MHz capacitively coupled discharges using mass spectrometry , 2008 .

[9]  G. Curley.  The dynamics of the charged particles in a dual frequency capacitively coupled dielectric etch reactor. , 2008 .

[10]  You-nian Wang,et al.  Numerical investigation of ion energy distribution and ion angle distribution in a dual-frequency capacitively coupled plasma with a hybrid model , 2007 .

[11]  O. V. Braginsky,et al.  Experimental and Theoretical Study of Ion Energy Distribution Function in Single and Dual Frequency RF Discharges , 2007, IEEE Transactions on Plasma Science.

[12]  D. Marić,et al.  Negative ions in single and dual frequency capacitively coupled fluorocarbon plasmas , 2007 .

[13]  Z. Donkó,et al.  Analysis of a Capacitively Coupled Dual-Frequency CF4 Discharge , 2006 .

[14]  J. Booth,et al.  Fluorine negative ion density measurement in a dual frequency capacitive plasma etch reactor by cavity ring-down spectroscopy , 2006 .

[15]  A. Ellingboe,et al.  Effect of radio-frequency power levels on electron density in a confined two-frequency capacitively-coupled plasma processing tool , 2006 .

[16]  R. Piejak,et al.  Hairpin resonator probe measurements in RF plasmas , 2005 .

[17]  T. Chung.  Scaling laws for dual radio-frequency capacitively coupled discharges , 2005 .

[18]  A. Bogaerts,et al.  Numerical simulation of dual frequency etching reactors: Influence of the external process parameters on the plasma characteristics , 2005 .

[19]  A. Lichtenberg,et al.  Principles of Plasma Discharges and Materials Processing: Lieberman/Plasma 2e , 2005 .

[20]  A. Ellingboe,et al.  Electrostatic modelling of dual frequency rf plasma discharges , 2004 .

[21]  Benjamin Alexandrovich,et al.  The hairpin resonator: A plasma density measuring technique revisited , 2004 .

[22]  A. Ellingboe,et al.  Independent control of ion current and ion impact energy onto electrodes in dual frequency plasma devices , 2004 .

[23]  A. Bogaerts,et al.  Numerical investigation of ion-energy-distribution functions in single and dual frequency capacitively coupled plasma reactors. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[24]  S. Moon,et al.  Redeposition of etch products on sidewalls during SiO2 etching in a fluorocarbon plasma. III. Effects of O2 addition to CF4 plasma , 2003 .

[25]  A. Bogaerts,et al.  Particle-in-cell/Monte Carlo simulation of a capacitively coupled radio frequency Ar/CF4 discharge: Effect of gas composition , 2003 .

[26]  N. Hara,et al.  Corrosion Behavior of Stainless Steel and Aluminum in a Downstream Environment of CF 4 / O 2 Microwave Plasma , 2002 .

[27]  A. Tanaka,et al.  Enhancement of Etch Rate by the Addition of O2 and Ar in Chemical Dry Etching of Si Using a Discharge Flow of Ar/CF4 and CF4/O2 Gas Mixtures , 2001 .

[28]  M. Lieberman,et al.  Electronegativity of low-pressure high-density oxygen discharges , 2001 .

[29]  T. Kitajima.  Functional separation of biasing and sustaining voltages in two-frequency capacitively coupled plasma , 2000 .

[30]  A. Wendt,et al.  Control of ion energy distribution at substrates during plasma processing , 2000 .

[31]  K. Ohe,et al.  Probe measurements and global model of inductively coupled Ar/CF4 discharges , 1999 .

[32]  K. Nanbu,et al.  Self-consistent particle simulation of radio-frequency CF4 discharge with implementation of all ion–neutral reactive collisions , 1998 .

[33]  S. Rauf,et al.  Argon metastable densities in radio frequency Ar, Ar/O2 and Ar/CF4 electrical discharges , 1997 .

[34]  Kando,et al.  Negative ions in a radio-frequency oxygen plasma. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[35]  G. Kroesen,et al.  Measurements of negative ion densities in 13.56-MHz rf plasmas of CF4, C2F6, CHF3, and C3F8 using microwave resonance and the photodetachment effect , 1991 .

[36]  R. Stenzel,et al.  Microwave resonator probe for localized density measurements in weakly magnetized plasmas , 1976 .