Model-Based Analysis of Plasma Parameters and Active Species Kinetics in Cl[sub 2]∕X (X=Ar, He, N[sub 2]) Inductively Coupled Plasmas

Abstract

This work reports the influence of gas mixing ratio on the normalCl2∕Ar , normalCl2∕He , and normalCl2∕normalN2 plasma parameters, steady-state densities, and fluxes of active species in the planar inductively coupled plasma reactor. The investigation combined plasma diagnostics by Langmuir probes and quadrupole mass spectroscopy with a global (zero-dimensional) plasma model. It was shown that the dilution of Cl2 by any additive gas results in a noticeable change in both the electron temperature and density, as well as provides the acceleration in the electron impact dissociation kinetics of Cl2 molecules. No qualitative differences for the given three systems in regard to relative changes in active species densities and model-predicted etch rate behaviors were obtained.

A Comparative Study of HBr-Ar and HBr-Cl2 Plasma Chemistries for Dry Etch Applications

“…High electron impact dissociation rate for Cl 2 (k 15 = 1.12 9 10 -8 -1.23 9 10 -8 cm 3 s -1 compared with k 1 = 1.72 9 10 -9 -1.98 9 10 -9 cm 3 s -1 for 0-100% Cl 2 due to higher dissociation cross-section and lower threshold energy) not only maintains high rates of R33, R35 and R37 in the HBr-rich plasmas, but also provides the domination of Cl atoms in the Cl 2 -rich plasmas with n Cl =n Cl 2 ¼ 1:5 À 3:5 for 60-100% Cl 2 . The last result is in good agreement with earlier published works on both diagnostics and modeling of Cl 2 -based ICPs [26,28]. In addition, since in the HBr-rich plasmas the decay of Cl atoms is noticeably contributed by R33 and R35 (for example, k 33 n HBr þ k 35 n Br 2 ¼ 360 s À1 versus k 47 = 450 s -1 for 40% Cl 2 ), the sensitivity of modeling results to c Cl is rather low up to 60-70% Cl 2 in HBr/Cl 2 gas mixture.…”

“…[27] (*0.075 at 350 K) for mono-Si surface in pure Br 2 gas. The value of c Cl & 0.05 was chosen according to our work [28] where it provided an acceptable agreement between measured and model-predicted Cl 2 /X (X = Ar, He, N 2 ) plasma parameters in the same ICP reactor as was used for the current study. This is quite close to c Cl values derived in Refs.…”

Optimization of Mesa Etch for a Quasi-Vertical GaN Schottky Barrier Diode (SBD) by Inductively Coupled Plasma (ICP) and Device Characteristics

“…Cl 2 was used as a primary etching gas for the PR-masked etching samples [15]. To investigate the impact of ICP and RF power on the etched sidewall profile, the chamber pressure, flow rate of Cl 2 , and etching time were kept identical.…”

On the Etching Characteristics and Mechanisms of HfO<SUB>2</SUB> Thin Films in CF<SUB>4</SUB>/O<SUB>2</SUB>/Ar and CHF<SUB>3</SUB>/O<SUB>2</SUB>/Ar Plasma for Nano-Devices

“…Earlier, it was shown that such an approach works not bad even for more electronegative plasmas, for example, for the Cl 2 -bàsed ones. 21 Copyright: American Scientific Publishers zero-dimensional model with Maxwellian electron energy distribution function (EEDF) and with the experimental data on T e and n + as input parameters. 21 22 Though the real EEDFs are not exactly Maxwellian, such simplification for both the CF 4 -and CHF 3 -based low-pressure (p < 50 mTorr) ICPs provides the reasonable agreement between the results of plasma diagnostics and modeling.…”