Interaction of F atoms with SiOCH ultra-low- k films: I. Fluorination and damage

Two approaches to the modeling of surface kinetics in reactive plasmas are discussed. Coarse‐grained deterministic models incorporate rate balance equations for coverages of surface active sites. They are computationally effective and can be readily coupled to reactor‐scale plasma simulations. In the kinetic Monte Carlo (KMC) approach, the time evolution of a gas‐lattice system consisting of a large number of particles is described. Although being more demanding computationally, KMC algorithms are exact, allow a straightforward description of distributions of surface reactivity and help bridging the gap between simulations on atomic and macroscopic scales. In this paper, theoretical and practical aspects of deterministic and KMC modeling of plasma‐surface interactions are discussed taking O recombination on silica as a model system.

Section: Further Challengesmentioning

confidence: 99%

Deterministic and Monte Carlo methods for simulation of plasma‐surface interactions

Marinov

Teixeira

Guerra

2016

“…One of the most damaging steps is patterning (due to etching), which is typically conducted in fluorocarbon‐based plasma. In this case, low‐k film is mainly damaged by F atoms causing essential modification of pore surface due to the chemical reactions of atomic fluorine with surface –CH 3 groups and SiO x matrix . Besides, high‐energy vacuum ultra violet (VUV) photons generated in plasma can also provide Si–CH 3 decomposition .…”

Section: Introductionmentioning

confidence: 99%

“…To avoid these undesired effects fundamental understanding of damage mechanisms, i.e., interaction of VUV photons and F atoms with OSG, is required. The mechanisms of separate interaction of VUV photons, as well as F atoms with porous OSG dielectrics were previously investigated . It was found that OSG modification (mainly with removal of surface –CH 3 groups) occurs due to VUV light absorption with excitation of O x Si–CH 3 complexes and the following expenditure of the excitation energy part to Si–CH 3 bond break.…”

Section: Introductionmentioning

confidence: 99%

Synergistic effect of VUV photons and F atoms on damage and etching of porous organosilicate films

Lopaev

Zyryanov

Zotovich

et al. 2018

Synergistic effect between VUV photons and F atoms in both damage and etching of porous organosilicate (OSG) low-k films was studied. It was shown that both the OSG damage and etching rates by F atoms notably drop with decreasing temperature due to the existence of activation energy while the rate of the VUV-induced damage practically does not change. The joint exposure can significantly exceed the sum of the separate effects of VUV photons and F atoms. The reason is that absorbed photons energy allows F atoms to overcome the activation barrier especially under lowered temperature. A possible mechanism of F atom surface reactions assisted by VUV photons is analyzed and discussed. K E Y W O R D S fluorine, low-K dielectrics, photon-induced treatment, synergistic effect, VUV degradation Plasma Process Polym. 2018;15:e1700213.www.plasma-polymers.com

“…Using ab initio calculations, Mankelevich et al reported that the F atom reacts with Si‐O bonds via a pentavalent Si state. They proposed that fast fluorination initially occurs without significant modification of the chemical structure and the pentavalent Si states weaken adjacent Si‐O bonds, leading to the breakage of Si‐O bonds with successive removal of CH 3 and CH 2 groups from SiOC films …”

Section: Process Optimizations and Improvementsmentioning

confidence: 99%

Review of methods for the mitigation of plasma‐induced damage to low‐dielectric‐constant interlayer dielectrics used for semiconductor logic device interconnects

Miyajima

Ishikawa

Sekine

et al. 2019

The developments in advanced interconnect technology for semiconductor logic devices for the mitigation of plasma‐induced damage to low‐dielectric‐constant (low‐k) materials, including fluorosilicate glass and carbon‐doped silicon oxide is reviewed. The chemical bond structures of low‐k materials are summarized to help mitigate the k value degradation caused by moisture uptake after plasma processes. Damage suppression is accomplished by integrating deposition chemistries, pattern etch transfer, and post‐etch cleaning technologies. On the basis of analyses results, a discussion on the bond engineering of low‐k materials and their degradation during plasma processing is given. Challenges facing low‐k interconnect technology are also addressed.