Predictive study of a plasma structure and function in reactive ion etcher driven by very high frequency: Validity of an extended two-dimensional relaxation continuum model

Abstract

The plasma structure and physical function of a narrow gap reactive ion etcher (RIE), consisting of capacitively coupled parallel plates driven at 100 MHz, have been predicted in a proper manner by an extended relaxation continuum model including gas flow and sputtered particle transport from the substrate. Monitoring the spatiotemporal excitation rate gives validity to the use of the continuum model even at 50 mTorr under higher power condition mainly maintained by an ionization multiplication of the secondary electrons ejected from the powered electrode by ion impacts. The plasma structures are testified by comparing the two-dimensional net excitation rate of Ar(3p5) with the experimental computerized tomography image. A nonvolatile particle transport successive to the physical etching on the substrate has been predicted in the RIE under a feed gas flow.

Electron transport coefficients in SiH4and Si2H6in dc and rf fields

“…where the first term gives the mean value (see equation (10)), and the second determines the additional local term proportional to the density gradient that will be obtained by calculating components g 1 (v, t) and spatial swarm profile n(r, t). The axial mean energy of the swarm with Gaussian density, peaked at z = 0, is shown in figure 11 for 1 MHz and in figure 12 for 100 MHz at each of phases, (a) 0, (b) 3π/10, (c) π/2, and (d) 9π/10.…”

“…The basic tool for plasma modelling is fluid codes which require special corrections in order to provide a description of the non-local transport of electrons. A very basic and successful approach to this problem is application of the relaxation continuum technique (RCT) [8,9] which was shown to provide excellent quantitative agreement with the experimental data [9,10].…”

Transport coefficients and scattering cross-sections for plasma modelling in CF4-Ar mixtures: a swarm analysis

“…This can be achieved only through comparisons of the well-defined multi-dimensional experimental data obtained from specific reference experiments and the results of calculations of realistic, well-developed and tested numerical models. This is especially important since high hopes have been focused on computer aided design (CAD) and control of plasma processing reactors [2,3].…”

A series of modeling of plasma etching and damage reduction: vertically integrated computer aided design for device processing

“…The gas phase module provides macroscopic plasma structure/function, and the feed gas¯ow and particle¯ow produced in the gas phase and on the wafer with microscopic structures in the plasma etcher ( Fig. 3) by using an extended relaxation continuum (E-RCT) model [6] under the database of microscopic collision processes and external plasma conditions. It uses direct numerical procedure (DNP) of the phase space Boltzmann equation when at need, under the result of the plasma structure, to predict the velocity (or energy) distribution of ions, electrons, and high energy neutrals in front of the wafer [7±10].…”

“…8 (see Ref. [6]). It can be concluded from this typical example that the¯ow pattern of the nonvolatile particle is completely different from the feed gas¯ow in the oxide etcher.…”