Electrical optimization of plasma-enhanced chemical vapor deposition chamber cleaning plasmas

Abstract

Articles you may be interested inRoom temperature synthesis of carbon nanofibers containing nitrogen by plasma-enhanced chemical vapor deposition Appl.Silicon nitride thin films deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition Evaluation of trifluoroacetic anhydride as an alternative plasma enhanced chemical vapor deposition chamber clean chemistry Fluorinated gas discharges are widely used by the semiconductor industry in etching and chamber cleaning applications, but the performance of these discharges varies in unpredictable ways, for unknown reasons believed to be electrical in origin. To investigate possible mechanisms for this behavior, we have measured the electrical characteristics of NF 3 /Ar, CF 4 /O 2 /Ar, and C 2 F 6 /O 2 /Ar chamber cleaning plasmas at 6.7-267 Pa in a 13.56 MHz, capacitively coupled, parallel-plate reactor, using radio-frequency current and voltage probes and optical emission spectroscopy. From the measurements, power losses in the external circuitry surrounding the discharge were determined. Furthermore, using the measurements and equivalent circuit models, the mechanisms by which power was absorbed within the discharge itself were investigated. Power was absorbed most efficiently at particular values of the discharge impedance. These optimal impedances occur in the middle of a transition from capacitive impedances at low pressures to resistive impedances at high pressures. These results illustrate that the plasma impedance is a useful parameter for monitoring and optimizing plasma processes in highly electronegative gases.

Effect of low temperature oxidation on dielectric properties of mercury sensitized photo-deposited silicon nitride films

“…The other three peaks (A, B and C) centered around 101.4 eV, 102.7 eV and 103.6 eV are attributed to Si 3 N 4 , SiN x O y and SiO 2 respectively. The binding energy of the peaks assigned to Si 3 N 4 , SiN x O y and SiO 2 matches quite well with the studies reported earlier [16][17][18][19][20]. The presence of both SiN x O y and SiO 2 peaks in Si 2p spectra clearly shows the incorporation of oxygen in all samples.…”

Ion energy distributions and optical emission spectra in NF3-based process chamber cleaning plasmas

“…The relatively low concentration of He ϩ observed is consistent with previous plasma impedance measurements which showed NF 3 /He plasmas to be more electronegative than NF 3 /Ar plasmas. 5, 6 We will discuss the effect of increased electronegativity on ion energy in Sec. III B. NF 2 ϩ is one of the dominant ion species observed for 25 mol % NF 3 /He discharges.…”

“…[20][21][22] All three trends are manifestations of changes in plasma impedance, and we can correlate the trends observed here with plasma impedance measurements in previous studies of NF 3 -based plasmas. [5][6][7] To facilitate our analysis, we outline three fundamental physical processes as pressure and electronegativity change.…”

“…Diluent or buffer gases are commonly used to optimize both fluorocarbon-or NF 3 -based chamber cleaning process plasmas. [5][6][7][8][9][10] High etch rates and shorter chamber cleaning times in NF 3 -based plasmas have been achieved by using high-pressure ͑1-3 Torr͒ and high-power density ͑0.5-2 W/cm 2 ͒. 5,7 While etch-rate-optimized plasmas improve the availability and overall productivity of PECVD tools, gradual hardware degradation over time may occur due to bombardment by large fluxes of high-energy ions.…”

Role of N2 during chemical dry etching of silicon oxide layers using NF3/N2/Ar remote plasmas

“…The remote plasma cleaning processes of the silicon dioxide and silicon nitride layers using PFCs such as C 2 F 6 , C 3 F 8 , C 4 F 8 , and NF 3 have been studied and used in the flat panel display (FPD) industry [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. The PFCs that are reemitted during chamber etching, however, are known to have a serious global warming effect in the atmosphere [10][11][12][13][14][15][20][21][22][23][24][25][26].…”