He plasma pretreatment effects on oxygen plasma-induced carbon loss and surface roughening in an ultralow-k organosilicate glass film

Abstract

Ex situ Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) have been used to characterize the effects of He plasma pretreatment on O2 plasma-induced modification of the surface composition and structure of nanoporous ultralow dielectric constant (k) organosilicate glass (OSG) films. Oxygen plasma induces Si–C bond scission and carbon abstraction, and increased k values. Carbon abstraction exhibits diffusion-dominated kinetics. FTIR data, however, indicate that He plasma pretreatment prior to O2 plasma exposure induces pore sealing in the OSG film interior, inhibiting carbon abstraction, but only at longer O2 plasma exposure times (exposure time >5 min). The data are consistent with XPS data showing that OSG exposure to He plasma results in a more SiO2-like surface layer, but that atomic O will diffuse through a continuous SiO2 film. AFM data also indicate that He plasma pretreatment inhibits subsequent OSG surface roughening upon exposure to oxygen plasma.

Ar ions and oxygen plasma interactions of amine terminated organosilicate glass: A combined experimental and ab initio simulations study

“…2(a), bottom trace] can be decomposed into two spectral components with binding energies of $284 eV and 285 eV, corresponding to Si-C and C-C bonding environments, respectively. 2,19 Similarly, N(1s) spectra Fig. 2 6,20 therefore, it is difficult to resolve both features in the same spectrum.…”

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

“…Ion bombardment enhances the formation of a SiO 2 -like layer in O 2 plasma. [106,107] Using the Vienna Ab initio Simulation Package, Chaudhari et al [108][109][110] found that the lowest activation energy of Si-CH 3 bond scission and Si-O formation is 0.1 eV, resulting in the formation of H 2 O and Si-OH. Recently, Rimsza et al [111] performed a molecular dynamics simulation using reactive force field and LAMMPS package and showed that Si-O-Si linkages correlate with increasing Si-OH fraction and decreasing Q 4 that porosity includes T 3 and D 2 units.…”

“…The fundamental mechanism of the plasma‐induced damage of SiOC films in oxygen plasma was studied by Goldman et al Oxygen atoms penetrate and diffuse into SiOC films, damaging SiOC via Si‐OH formation. Ion bombardment enhances the formation of a SiO 2 ‐like layer in O 2 plasma . Using the Vienna Ab initio Simulation Package, Chaudhari et al found that the lowest activation energy of Si‐CH 3 bond scission and Si‐O formation is 0.1 eV, resulting in the formation of H 2 O and Si‐OH.…”