Remote Plasma‐Enhanced Chemical Vapor Deposition of SiO2 Using Ar/  N 2 O  and SiH4

Abstract

Remote plasma-enhanced chemical vapor deposition of Si02 using a radio-frequency (rf) Ar/N20 plasma and downstream-injected SiH4 was investigated. The deposition rate at 20 W rf power was measured as a function of pressure, temperature, and SiH4 flow rate. The Si02 deposition rate at 300°C and 300 mTorr depends linearly on the SiH4 flow rate. The deposition rate is independent of N30 flow rate for N20/SiH4 ratios much greater than 1, consistent with oxygen saturation of the growth surface. The deposition rate increases linearly with pressure up to 400 mTorr. A plateau in the deposition rate is observed above 400 mTorr, and is ascribed to the onset of parasitic gas-phase reactions leading to particle formation. Negative apparent activation energies are observed at pressures 400 mTorr, suggesting that adsorption of Si-bearing species is the rate-limiting step in SiO, deposition. The deposition chemistry was probed using real-time quadrupole mass spectrometry (QMS) and optical emission spectroscopy (OES). The H and H2O QMS signal intensities increase monotonically with SiH4 flow rate; approximately 0.67 moles of H3 and 1.33 moles of H20 are produced per mole of SiH4 consumed. OES evidences the presence of Ar metastables, N2 metastables, excited NO molecules, and atomic 0 in the plasma. Fourier transform infrared spectroscopy of thick Si02 films demonstrated that Si-H and Si-OH groups are present at very low concentrations (<1 atom %).Single-wavelength ellipsometry indicated that films deposited under typical 0-rich conditions have an average refractive index of 1.464.

Functionally Graded Alumina/Mullite Coatings for Protection of Silicon Carbide Ceramic Components From Corrosion

“…As a result, the concentrations of all gas phase species that are included in the heterogeneous chemistry mechanism are by several orders magnitude in the case of MTS before partial equilibrium is reached (see Figures 2 and 7). From the evolution of the rates of the elementary reactions in the homogeneous chemistry mechanism, it was concluded in the preceding section that the higher concentrations of Si in accordance with the results of the analysis of the gas phase of silicon oxide CVD reactors using spectroscopic methods [68,69].…”

Electron drift velocity in N2O in strong electric fields determined from rf breakdown curves

“…RF discharges in N 2 O + SiH 4 mixtures are used for depositing amorphous oxynitrides films (a-SiN x O y and a-SiN x O y : H) [3][4][5][6][7]. In a number of cases rf discharges in N 2 O + SiH 4 mixtures are used to deposit SiO 2 films [8][9][10][11][12]. Typically the N 2 O concentration in the N 2 O + SiH 4 mixture is 2-40 times higher than that of silane.…”

Modeling and measurement of monomer pressure evolution in an inductively coupled pulsed plasma reactor for thin polymer films

“…where current is in amperes and pressure is in Torr. Finally, using the ionization gauge sensitivity ratios of Nakao [14], the calibration equation for this fast ionization gauge in air is (5) III. TRANSIENT PRESSURE MODEL…”

“…Earlier investigations have shown that deposition rate is a strong function of monomer pressure [1]- [6]. For example, it has been observed in continuous plasma reactors that as pressure is increased deposition rates reach a maximum and then plateau or decrease [1], [5], [6]. This phenomenon was explained by assuming a change in deposition mechanism occurs above a certain pressure leading to an increased particle formation in the gas phase [5], [7].…”

“…For example, it has been observed in continuous plasma reactors that as pressure is increased deposition rates reach a maximum and then plateau or decrease [1], [5], [6]. This phenomenon was explained by assuming a change in deposition mechanism occurs above a certain pressure leading to an increased particle formation in the gas phase [5], [7]. Furthermore, Tsai [3] found a very high particle formation rate at lower pressures ( 0.8 torr) while producing powder-free films at pressures between 0.8 and 1.2 torr.…”