Sequential chemical vapor deposition

• US 6,342,277 B1
• Filed: 04/14/1999
• Issued: 01/29/2002
• Est. Priority Date: 08/16/1996
• Status: Expired due to Term

• Current Assignee: ASM International NV
• Original Assignee: Licensee For Microelectronics ASM America Incorporated
• Inventors: Sherman, Arthur
• Primary Examiner(s): MEEKS, TIMOTHY HOWARD
• Application Number:
  US09/291,807
• Time in Patent Office: 1,021 Days
• Field of Search: 427/252, 427/255.31, 427/255.394, 427/255.7, 427/562-564, 427/576, 427/579, 117/92, 117/103, 117/104
• US Class Current: 427/562
• 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 including a plurality of cycles, wherein at least one cycle comprises:

placing a part in a chamber, wherein the part comprises a semiconductor substrate having at least one opening therein and the film coats walls defining the opening;

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

purging the chamber of the gaseous first reactant;

converting the portion of the first reactant adsorbed on the part to either an element or compound by exposing the part to a gaseous second reactant that includes radicals created by a plasma discharge, whereby a thin film is formed; and

purging the chamber of the gaseous second reactant;

wherein the first reactant comprises a molecule containing a metal atom and converting comprises reducing the portion of the first reactant adsorbed on the part to metal; and

wherein reducing the portion of the first reactant adsorbed on the part to metal comprises;

first reducing the portion of the first reactant adsorbed on the part to an initial metal oxide; and

second reducing the initial metal oxide to metal by exposure to hydrogen radicals.

2. The process of claim 1, wherein the first reducing comprises exposing the part to oxygen radicals.

3. A process of growing a thin film by a sequential chemical vapor deposition process including a plurality of cycles, wherein at least one cycle comprises:

placing a part in a chamber;

exposing the part to a gaseous first reactant including metal, wherein at least a portion of the first reactant adsorbs on the part;

purging the chamber of the gaseous first reactant;

initially reducing the portion of the first reactant adsorbed on the part to an initial metal oxide by exposing the part to a gaseous second reactant;

purging the chamber of the gaseous second reactant;

further reducing the initial metal oxide to metal by exposing the part to a gaseous third reactant; and

purging the chamber of the gaseous third reactant.

4. The process of claim 3, wherein the gaseous third reactant includes hydrogen radicals.

5. The process of claim 3, wherein the gaseous second reactant includes oxygen radicals.

6. The process of claim 3, wherein the metal comprises copper.

7. The process of claim 3, further comprising additional cycles wherein the portion of the first reactant adsorbed is directly reduced to metal, without the initial metal oxide.

8. The process of claim 7, wherein the part includes metallic surfaces and non-metallic surfaces and whereby the initial metal oxide avoids selective deposition on the part.

9. The process of claim 3, further comprising purging the gaseous second reactant between initially reducing and further reducing.

10. The process of claim 9, further comprising purging the chamber of reactants after further reducing and prior to further cycles.