Numerical Simulation of a Single‐Wafer Isothermal Plasma Etching Reactor

Abstract

A two-dimensional finite element simulation of gas flow and reactive species distribution in a parallel-plate singlewafer isothermal reactor was conducted. The oxygen plasma etching of polymer under high pressure (-1 torr), high frequency (13.56 MHz) conditions was chosen as a model system for analysis with emphasis on chemical etching. Etching rate and uniformity were examined as a function of reactor geometry and operating conditions. A maximum in etching rate with flow rate was observed, and this maximum shifted to higher flow rates as the power increased. The pressure dependence of the etching rate was complex, but in genera] a broad maximum in etching rate with pressure existed, which shifted to higher pressures as the flow rate increased. Etching rate increased but etching uniformity degraded as the wafer reactivity increased. A shower radius at least equal to the wafer radius, and a plasma radius slightly greater than the wafer radius were found to give the best etching rate and uniformity results under the conditions examined. Two novel reactor designs were also studied, namely, a reactor with a graded gas velocity at the shower, and a pulsed-plasma reactor. When compared to the conventional reactor, the new designs can yield improved uniformity and etching rate (the etching rate of the pulsed-plasma reactor was prorated by the duty cycle). ABSTRACTSilicon surface contamination and near-surface damage of the Si(100) substrate caused by reactive ion etching (RIE) of SiO2 overlayer in C2FdCHF3 plasma were characterized by x-ray photoelectron spectroscopy (XPS), He-ion channeling technique and high-resolution transmission electron microscopy (HRTEM). XPS study indicates that a thin (<20A thick) C,F polymeric layer was formed on the Si surface and underneath the polymer film a thin oxide layer (-10A) was produced due to air exposure after RIE. These films were also characterized in terms of chemical composition and bonding

Effect of metastable oxygen molecules in high density power-modulated oxygen discharges

“…Similar findings were reported for an etching reactor. 19 Jiang et al 20 found that pulsing can alter the ratio of chemical species in CF 4 discharges, which in turn can affect etch selectivity. Overzet and co-workers 21,22 used a 1D fluid model for the electric field and particle densities in the afterglow of an rf discharge.…”

Two-Dimensional Self-Consistent Radio-Frequency Plasma Simulations Relevant to the Gaseous Electronics Conference Rf Reference Cell

“…Modeling and simulation of glow discharge plasmas has emerged as a tool for enhancing one’s intuition about the physicochemical processes occurring in the plasma, for understanding the complex spatiotemporal plasma dynamics, and for assisting in the design of new reactors or the optimization of existing ones. Two-dimensional plasma reactor simulations have been reported in the literature in recent years [ 3 – 5 ]. However, these works focused on the transport and reaction of neutrals only (neutral transport and reaction models).…”

Gas flow characteristics of argon inductively coupled plasma and advections of plasma species under incompressible and compressible flows

“…It could enhance plasma transport and result in non-monotonic varia-tion of plasma density versus power. [14] The gas flow [15,16] is caused by the system that feeds gas into the reactor and the pumping setup. A gas flow channel is formed between the locations of gas entrance nozzle and pumping port.…”