Quantitative control of plasma and surface reactions for dielectric film etching

Abstract

This paper reviews reaction control in the dry etching of insulating films. High ion fluxes are required for high-speed SiO2 processing. However, because atomic F generation due to excessive fluorocarbon gas dissociation causes reduced selectivity, the number of electron collisions should be reduced by using short residence times. The C–F-based polymer thickness formed during processing varies based on the oxygen content of the material to be etched. To achieve high etch selectivity, the incident flux balance must be adjusted quantitatively to ensure that the polymer becomes thinner during etching and thicker as the underlying material is exposed. Even under high selectivity conditions, incident ions cause damage at the moment the underlying material is exposed. To suppress this damage, the ion penetration depth, which depends on both ion energy distribution and ion composition, must be reduced. Recently, atomic layer etching combined with C–F polymer deposition and removal using Ar ion irradiation has been studied. To improve the accuracy of such cyclic etching processes, it is important to understand and control the transient states of both plasma and surface reactions quantitatively.

Modeling and simulation of coverage and film properties in deposition process on large-scale pattern using statistical ensemble method

“…According to our assumed mechanism, the control of the dissociation degree of gas is crucial to the SiN-PECVD process at low temperature. Tatsumi et al 92,93) reported the relation among the dissociation degree ζ, residence time τ, electron density N e , and collision cross-section 〈σv〉 as follows:…”

Science-based, data-driven developments in plasma processing for material synthesis and device-integration technologies

“…71) Reactive plasma is used for etching the insulating dielectric films, such as silicon dioxide, 72) silicon nitride, 73) silicon oxyfluoride, 74) and silicon oxycarbide. [75][76][77][78] Since the late 1990s, anisotropic etching has been used for the fabrication of deep holes and trenches with dimensions narrower than 100 nm and high-aspect ratios 48) In pulsed plasmas, negative ions can be extracted from the bulk plasma to boundary surface applying electrical reversal potential or positive bias. 50) of more than 20.…”

Review and future perspective of feature scale profile modeling for high-performance semiconductor devices

“…In the reactive ion etching (RIE) processes, such as atomic layer etching (ALE), 4 – 10 etching processes of the transistors require not only high etching selectivity on the Si fin against mask materials but also low damage on a nanometer scale. As the space between the transistors becomes shorter, verticality of high aspect ratio contact (HARC) etching and high selectivity against the Si substrate is essential considerations.…”