Sequential chemical vapor deposition

• US 20010028924A1
• Filed: 05/24/2001
• Published: 10/11/2001
• Est. Priority Date: 08/16/1996
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: Dr. Arthur Sherman
• Inventors: Sherman, Arthur
• Granted Patent: US 6,652,924 B2
• Time in Patent Office: Days
• US Class Current: 427/255.28
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/4554 Plasma being used non-continuously in between ALD reactions C23C16/56 takes precedence
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: C23C 16/45544 characterized by the apparatus
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases

Abstract

The present invention provides for sequential chemical vapor deposition by employing a reactor operated at low pressure, a pump to remove excess reactants, and a line to introduce gas into the reactor through a valve. A first reactant forms a monolayer on the part to be coated, while the second reactant passes through a radical generator which partially decomposes or activates the second reactant into a gaseous radical before it impinges on the monolayer. This second reactant does not necessarily form a monolayer but is available to react with the monolayer. A pump removes the excess second reactant and reaction products completing the process cycle. The process cycle can be repeated to grow the desired thickness of film.

Claims

1. A process of growing a thin film by a sequential chemical vapor deposition process, comprising the steps of:

placing a part in a chamber;

evacuating the chamber of gases;

exposing the part to a gaseous first reactant, including an element of the thin film to be formed, wherein the first reactant adsorbs more than one monolayer on the part;

evacuating the chamber of gases;

exposing the part, coated with multiple monolayers of the first reactant, to a gaseous second reactant of radicals, wherein the radicals convert the first reactant on the part to multiple monolayers of either an element or compound, wherein a thin film is formed; and

evacuating the chamber of gases.

2. The process of

claim 1

, wherein the parts to be coated are maintained at a temperature high enough to prevent liquid condensation, but low enough to allow multiple monolayers of the gaseous first reactant to remain on the part after chamber evacuation.

3. The process of

claim 1

, wherein the radicals of the second reactant are generated remotely in a radical generator in communication with the chamber.

4. The process of

claim 1

, wherein the first reactant is a molecule containing silicon and the second reactant is atomic oxygen which converts the first reactant to a thin film of silicon dioxide.

5. The process of

claim 1

, wherein the first reactant is a molecule containing silicon and the second reactant is atomic nitrogen which converts the first reactant to a thin film of silicon nitride.

6. The process of

claim 1

, wherein the first reactant is a molecule containing aluminum and the second reactant is atomic oxygen which converts the first reactant to a thin film of aluminum oxide.

7. The process of

claim 1

, wherein the first reactant is a molecule containing a metal atom and the second reactant is atomic hydrogen which converts the first reactant to a thin film of pure metal.

8. The process of

claim 1

, wherein the first reactant is a molecule containing a metal atom and the second reactant is HN radical which converts the first reactant to a thin film of metal nitride.

9. The process of

claim 1

, wherein the first reactant is a molecule containing a metal atom and the second reactant is atomic oxygen which converts the first reactant to a thin film of metal oxide.

10. A process of growing a thin film by a sequential chemical vapor deposition process, comprising the steps of:

placing a part in a chamber;

purging the chamber with an inert gas which will be the source gas for the radical;

exposing the part to a gaseous first reactant, including an element of the thin film to be formed, wherein the first reactant adsorbs on the part;

purging the chamber with an inert gas which will be the source gas for the radical;

exposing the part, coated with the first reactant, to a gaseous second reactant of radicals created by a plasma discharge in the inert gas, wherein the radicals convert the first reactant on the part to either an element or compound, wherein a thin film is formed; and

extinguishing the discharge and using the flowing inert gas to purge the reactor chamber.

11. A process of growing a thin film by a sequential chemical vapor deposition process, comprising the steps of:

placing a part comprising multiple high aspect ratio holes or trenches in a chamber;

evacuating the chamber of gases;

exposing the part to a gaseous first reactant, including an element of the thin film to be formed, wherein the first reactant adsorbs one or more monolayers on the part;

evacuating the chamber of gases;

exposing the part, coated with one or more monolayers of the first reactant, to a gaseous second reactant of radicals, wherein the radicals convert some of the first reactant on the part to one or more monolayers of either an element or compound, wherein a thin film is formed; and

evacuating the chamber of gases including any reaction products that had been formed.

repeating the radical exposure and pump out sequence sufficient times to ensure that all of the first reactant adsorbed onto the part is fully reacted.

12. A process of growing a thin film by a sequential chemical vapor deposition process, comprising the steps of:

placing a part in a chamber;

evacuating the chamber of gases;

exposing the part to a gaseous first reactant, including a first element of the thin film to be formed, wherein the first reactant adsorbs one or more monolayers on the part;

evacuating the chamber of gases;

exposing the part, coated with one or more monolayers of the first reactant, to a gaseous reactant of radicals, wherein the radicals convert some of the first reactant on the part to one or more monolayers of either an element or compound, wherein a thin film is formed; and

evacuating the chamber of gases including any reaction products that had been formed.

repeating this process two or more times to grow a thin film composed of several monolayers of a first material.

exposing the part to a gaseous second reactant, including a second element of the thin film to be formed, wherein the second reactant adsorbs one or more monolayers on the part;

evacuating the chamber of gases;

exposing the part, coated with one or more monolayers of the second reactant, to a gaseous reactant of radicals, wherein the radicals convert some of the second reactant on the part to one or more monolayers of either an element or compound, wherein a second thin film is formed; and

evacuating the chamber of gases including any reaction products that had been formed.

repeating this process two or more times to grow a thin film composed of several monolayers of a second material.

repeating the above sequence to grow a thin film composed of alternating thin layers of two different materials where each material is two or more monolayers thick.