Poly-Si etching rate as a function of ion energies in Cl2 plasmas with 0% and 6% O2 addition (5% Ar addition) under 500 W ECR power and 5 mT. The lines represent fitting of the data by the TML model.
(a) Experimentally measured poly-Si etching rate (circle) and normalized chlorine radical densities (square) under different O2 to total gas flow ratio under 500 W ECR power, 5 mT and 80 eV ion energy. Data points for the simulated etch rate by the feature scale model are shown as crosses. The inset shows the etching yield as a function of Cl flux to ion flux ratio reported by Chang et al. (Ref. 48 ) Higher ion energy cases (200 eV and 500 eV) were obtained by extrapolating the experimental data. (b) TML simulation of the etch rate as a function of O2 addition to the plasma.
(Color online) Surface morphology measured by AFM for the surfaces etched by Cl2 plasmas with (a) 0% and (b) 10% of O2 addition under 5 mT pressure, 80 eV ion energy, and 500 W ECR power.
XPS spectra of p-Si surfaces etched using Cl2 plasmas with 0, 3, and 6% of O2 addition under 5 mT, 500 W ECR power, and 80 eV ion energy.
(a) Elemental composition of Si, O and Cl of the surface etched using Cl2 plasma with O2 addition for 2 min. Under 5mT, 500W ECR power and 80 eV ion energy with 5% Ar addition. The Cl (2p), O (1s) and Si (2p) peaks are normalized by their atomic sensitivity factor. (b) TML prediction of the surface composition. V represents vacancy fraction.
(a) Dominant ionic species measured by the mass spectrometer while etching silicon using Cl2 plasmas with 0% and 6% of O2 addition under 5 mT, 500 W ECR power and 80 eV ion energy. (b) TML simulation of the ionic etch products.
Signal intensity ratio of SiCl+ ion to Ar+ ion in Si etching obtained by using the QMS in Cl2 plasmas with 0% to 10% of O2 addition under 5 mT, 500 W ECR power, and various ion energy. Lines are to guide the eye only.
Electron density and the electron temperature of Cl2/O2 plasmas as a function of O2 percentages addition under 500 W ECR power and 5 mT.
(a) Etched trench top and bottom sidewall angle as a function of O2 addition and (b) representative SEM images of the samples etched for 80 s under 500 W, 5 mT, and 80 eV ion energy using Cl2 plasmas under various degrees of O2 addition. The scale bars shown are 100 nm.
(Color online) Comparison of the simulated and experimental etch profiles for samples etched for 40 s (top row) and 80 s (bottom row) at 500 W, 5 mT, and 80 eV ion energy using Cl2 plasmas under various degrees of O2 addition.
Reactions rate coefficients and threshold energies for the TML model.
Article metrics loading...
Full text loading...