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Surfactant-templated porous organosilicate glass low-k films have been deposited by using a tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) mixture with different ratios and Brij® 30 surfactant. The deposited films contain different concentrations of terminal methyl groups that are proportional to the MTEOS concentration. Increasing the methyl group concentration by changing the TEOS/MTEOS ratio decreases the open porosity, k-value, and Young's modulus and increases the mean pore radius, although the template concentration was kept constant. The plasma etch rate well correlates with the number of fluorine atoms penetrated into pores. Plasma damage by fluorine radicals depends on the carbon concentration in the films. It can be reduced by 60% when the carbon concentration in the films exceeds 10 at. % as measured by XPS (the films deposited with the TEOS/MTEOS ratio of 40/60). Damage to the dielectrics associated with exposure to vacuum ultraviolet photons is reduced by more than 70% for the same samples. [ABSTRACT FROM AUTHOR]

Polymer grafting of pore sidewalls is studied as a protecting agent against processing damage. Polymethyl-methacrylate (PMMA), an improved polystyrene (PS-pro), and a tailored plasma damage management polymer (PDM) are considered as potential candidates. PMMA and PS-pro show nonhomogeneous grafting properties, while PDM coat the pore sidewalls uniformly through the bulk of the porous low-k film. A k ∼ 2.2 porous spin-on glass is used as a vehicle for processing damage study. Approximately one monolayer is grafted on the pore walls, leading to a k-value increase up to Δk ∼ 0.2. Using grafted PDM, the porous low-k chemical stability in 0.5% diluted hydrofluoric acid is significantly improved. Concerning plasma damage, at constant etch depth methyl depletion is decreased, mainly in capacitive coupled plasma discharge showing high polymerizing character, leading to similar damage depth as found for a reference organo-silicate glass 2.7 low-k. However, moisture uptake is not improved, leading to significant drift in the dielectric constant. [ABSTRACT FROM AUTHOR]

Low temperature etching of organosilicate low-k dielectrics in CF3Br and CF4 plasmas is studied. The chemical composition of pristine and etched low-k films was measured by Fourier transform infrared spectroscopy. Reduction of plasma-induced damage at low process temperature is observed. It is shown that the plasma damage reduction is related to protective effects of accumulated reaction products (CHxFyBrz, SiBrx after CF3Br, and CFx polymers after CF4 plasma). The reaction products could then be removed by thermal annealing for the pores to become empty. In the case of CF4 plasma, the thickness of CFx polymer increases with the temperature reduction, which is measured by ellipsometry. This polymer layer leads to a strong decrease in the diffusion rate of fluorine atoms and, as a consequence, to reduction of plasma-induced damage. Bromine containing reaction products are less efficient for low-k surface protection against the plasma damage. [ABSTRACT FROM AUTHOR]

Structural, mechanical, and electrophysical properties of rhombohedral hafnium oxide (r‐HfO2) with space group R3, as well as properties of HfO2, ZrO2, and Hf0.5Zr0.5O2 with space group Pca21 are studied using quantum chemical calculations. The characteristic diffraction peak of 2θ r‐HfO2 is close to the characteristic diffraction peaks of tetragonal (t‐HfO2) and orthorhombic (f‐HfO2) hafnium oxide. The value of bulk modulus is 231 GPa, which is larger than one of the orthorhombic structures. The values of high intensity peaks of Raman spectrum are 670 and 540 cm−1. The bandgap width is 5.8 eV and the average value of dielectric constant is 35.34, which is higher than one of orthorhombic hafnium oxide. [ABSTRACT FROM AUTHOR]