Anisotropic deposition of silicon dioxide
AssigneeAT&T Bell Laboratories
InventorsEarl R. Lory, Leonard J. Olmer
Life of this patent
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Abstract
In a radio-frequency plasma deposition reactor (10), SiO.sub.2 is deposited from a source (16) of tetraethoxysilane (TEOS). The deposition is made to be anisotropic, that is, to be deposited preferentially on horizontal surfaces, by use in the deposition atmosphere of a constituency such as NH.sub.3 or NF.sub.3 which inhibits SiO.sub.2 deposition, along with a radio-frequency power in excess of 100 watts, which preferentially removes the inhibiting gas from horizontal surfaces through ion impact.
Claims16
A method for making an integrated circuit device comprising the steps of depositing silicon dioxide on a substrate by subjecting the substrate to a radio-frequency plasma in an atmosphere including a source of silicon and a source of oxygen, characterized in that:
- there is introduced into the atmosphere an inhibiting gas that inhibits the deposition of silicon dioxide on the substrate surface;
- and the radio-frequency plasma is formed by subjecting the atmosphere to radio-frequency power in excess of 100 watts, whereby the density of said inhibiting gas is reduced on horizontal surfaces of the substrate with respect to vertical surfaces of the substrate, thereby promoting preferential silicon dioxide deposition on the horizontal surfaces.
A method for making integrated circuits comprising the steps of:
- forming a first metal conductor pattern over a semiconductor substrate, placing the substrate on one electrode of a radio-frequency reactor having two electrodes, introducing into the reactor an atmosphere including tetraethoxysilane, exciting with radio-frequency power one electrode of the reactor so as to cause silicon dioxide to be deposited on the substrate, characterized in that:
- the excited electrode is excited with radio-frequency power in excess of 100 watts;
- and the atmosphere includes a gas that inhibits deposition of silicon dioxide on the substrate.
Dependencies are inferred from the claim text.