Method of forming dielectric film for semiconductor devices
AssigneesTokyo Electron Limited, Yasuhiro Horiike
InventorsYasuhiro Horiike, Kohei Kawamura
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Abstract
A dielectric film of a capacitor is formed using the plasma CVD apparatus. A thin Ta layer is deposited on a semiconductor wafer by using Ta(N(CH.sub.3).sub.2).sub.5 gas and H.sub.2 radicals. The thin Ta layer is then oxidized by O.sub.2 radicals to form a thin Ta.sub.2 O.sub.5 layer. An Si.sub.3 N.sub.4 layer is then formed on the Ta.sub.2 O.sub.5 layer by using SiH.sub.4 and NH.sub.3 gases. The Ta.sub.2 O.sub.5 layer and the Si.sub.3 N.sub.4 layer are alternately laminated one upon the other several times to form a dielectric film of laminated structure. The dielectric film can thus have a composition close to the stoichiometric composition and it can be made high in dielectric constant and excellent in withstand voltage.
Claims12
A method of forming a dielectric film of a semiconductor device on a substrate in a plasma CVD apparatus, comprising the steps of:
- keeping a process chamber, in which the substrate is housed, at a greatly reduced pressure while exhausting the chamber, supplying a source gas of organic tantalum compound and hydrogen radicals into the process chamber through different inlets, and thermally reacting the organic titanium compound and hydrogen in the process chamber, thereby uniformly depositing a tantalum layer containing organic substances derived from the source gas of the organic tantalum compound on the substrate;
- and
- keeping the process chamber at greatly reduced pressure while exhausting it and supplying oxygen radicals into the process chamber to oxidize the tantalum layer to form a Ta.sub.2 O.sub.5 layer as well as to oxidize and remove the organic substances therefrom;
- wherein the deposition of the tantalum layer and its oxidation are repeated thereby enabling the preparation of a dielectric film having plural Ta.sub.2 O.sub.5 layers.
Dependencies are inferred from the claim text.