Method of modifying source chemicals in an ald process
AssigneeASM International N.V.
InventorKai-Erik Elers
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Abstract
This invention concerns a method for modifying a source material used in an ALD process, a method for depositing transition metal nitride thin films by an ALD process and apparatus for use in such process. According to the present invention transition metal source materials are reduced by vaporizing a metal source material, conducting the vaporized metal source material, into a reducing zone comprising a solid reducing agent maintained at an elevated temperature. Thereafter, the metal source material is contacted with the solid or liquid reducing agent in order to convert the source material into a reduced metal compound and reaction byproducts having a sufficiently high vapor pressure for transporting in gaseous form.
Claims22
A method of reducing transition metal source materials and using them in an atomic layer deposition process, said method comprising:
- vaporizing a metal source material;
- conducting the vaporized metal source material into a reducing zone located in a flow channel connected to a reaction space, said reducing zone comprising a reducing agent maintained at an elevated temperature;
- reducing the vaporized metal source material into a reduced metal compound that can be transported in gaseous form by contacting the vaporized metal source material with the reducing agent;
- transporting the reduced metal compound into the reaction space;
- and
- utilizing the reduced metal compound in an atomic layer deposition process.
An atomic layer deposition process for producing transition metal nitride thin films on a substrate, comprising contacting a substrate in a reaction space with sequential, alternating vapor-phase pulses of:
- a) at least one metal source material;
- and
- b) at least one nitrogen source material,
- wherein the metal source material is reduced in a reducing zone located in a flow channel between a metal source material stock container and the reaction space prior to contacting the substrate.
An atomic layer deposition process for growing a transition metal nitride thin film on a substrate comprising:
- a) feeding a vapor-phase pulse of metal source material into a reduction zone;
- b) reducing the vapor-phase metal source material;
- c) conducting the reduced vapor-phase metal source material into a reaction space;
- d) contacting the reduced vapor-phase metal source material with a substrate in the reaction space to deposit a monolayer of a metal species on the substrate surface;
- e) purging the reaction space with an inert gas;
- f) feeding a vapor-phase pulse of a nitrogen source material into the reaction space;
- g) contacting the nitrogen source material with the metal species on the substrate surface to form a metal nitride;
- h) purging the reaction space with an inert gas;
- and
- i) repeating steps a) through h) until a metal nitride thin film of a desired thickness is formed.
Dependencies are inferred from the claim text.