METHODS FOR STABLE PROCESS IN A REACTIVE SPUTTERING PROCESS USING ZINC OR DOPED ZINC TARGET

• US 20110073463A1
• Filed: 09/28/2010
• Published: 03/31/2011
• Est. Priority Date: 09/28/2009
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ye, Yan
• Granted Patent: US 8,840,763 B2
• Time in Patent Office: Days
• US Class Current: 204/192.15
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/0676 Oxynitrides
• CPC Class Codes: C23C 14/3492 Variation of parameters during sputtering
• CPC Class Codes: C23C 14/35 by application of a magnetic field, e.g. magnetron sputtering C23C14/3457 takes precedence
• CPC Class Codes: C23C 14/564 Means for minimising impurities in the coating chamber such as dust, moisture, residual gases
• CPC Class Codes: H01J 37/3408 Planar magnetron sputtering

Abstract

Embodiments disclosed herein generally relate to a method for seasoning a sputtering target in-situ with a substrate to be processed. New semiconductor compounds containing oxygen, nitrogen, and an element such as zinc, cadmium, tin, indium, and gallium are beginning to replace silicon as the material for active channels in TFTs. The new semiconductor compounds may be deposited by a reactive sputtering process. During the sputtering process, reactive gas reacts with the metal from the sputtering target and deposits on the substrate. Some of the reactive gas may react at the surface and lead to a buildup of a compound at the target surface. Because oxygen and nitrogen are quite reactive, an oxide or nitride compound may develop at the target surface. The oxide or nitride may be removed by seasoning the sputtering target. The seasoning may occur while the substrate is within the processing chamber.

Claims

1. A method, comprising:

disposing a substrate onto a substrate support in a processing chamber, the processing chamber having a sputtering target disposed therein opposite the substrate support, the sputtering target comprising an element selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof;

performing a first seasoning process comprising;

introducing an inert gas and a nitrogen containing gas into the processing chamber; and

applying a DC bias to the sputtering target to sputter material from the target;

reducing the DC bias to a second DC bias; and

performing a first sputtering process comprising;

introducing an oxygen containing gas along with the inert gas and nitrogen containing gas;

increasing the DC bias to a third DC bias to sputter material from the target; and

depositing a first layer having a first composition on the substrate that comprises oxygen, nitrogen, and one or more elements selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof.

2. The method of claim 1, wherein substantially no material deposits on the substrate during the first seasoning process.

3. The method of claim 2, further comprising:

performing a second seasoning process after the first sputtering process, the second seasoning process comprising;

reducing the flow of the oxygen containing gas while continuing to flow the inert gas and the nitrogen containing gas into the processing chamber; and

sputtering material from the target.

4. The method of claim 3, further comprising:

performing a second sputtering process after the second seasoning process, the second sputtering process comprising;

introducing the oxygen containing gas along with the inert gas and nitrogen containing gas;

sputtering material from the target; and

depositing a second layer having a second composition different than the first composition on the first layer that that comprises oxygen, nitrogen, and one or more elements selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof.

5. The method of claim 4, wherein substantially no material deposits on the substrate during the second seasoning process.

6. The method of claim 1, wherein the nitrogen containing gas comprises N₂.

7. The method of claim 6, wherein the oxygen containing gas comprises N₂O.

8. The method of, claim 1, further comprising introducing a hydrogen containing gas into the processing chamber during the first seasoning process.

9. The method of claim 8, wherein the hydrogen containing gas comprises NH₃.

10. The method of claim 8, wherein the hydrogen containing gas comprises H₂.

11. A method, comprising:

disposing a substrate onto a substrate support in a processing chamber, the processing chamber having a sputtering target disposed therein opposite the substrate support, the sputtering target comprising an element selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof;

performing a sputtering process comprising;

introducing an inert gas, an oxygen containing gas, and a nitrogen containing gas into the processing chamber;

applying a DC bias to the sputtering target to sputter material from the target; and

depositing a layer on the substrate that comprises oxygen, nitrogen, and one or more elements selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof; and

performing a seasoning process comprising;

reducing the flow of oxygen containing gas to the processing chamber while continuing to flow the inert gas and the nitrogen continuing gas; and

sputtering material from the sputtering target while the substrate remains in the processing chamber.

12. The method of claim 11, wherein substantially no material deposits on the substrate during the seasoning process.

13. The method of claim 11, wherein the nitrogen containing gas comprises N₂.

14. The method of claim 13, wherein the oxygen containing gas comprises N₂O.

15. A method, comprising:

disposing a substrate onto a substrate support in a processing chamber, the processing chamber having a sputtering target disposed therein opposite the substrate support, the sputtering target comprising a metal selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof;

performing a first sputtering process comprising;

introducing an inert gas, an oxygen containing gas, and a nitrogen containing gas into the processing chamber;

applying a DC bias to the sputtering target to sputter material from the target; and

depositing a first layer having a first composition on the substrate that comprises oxygen, nitrogen, and one or more metals selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof;

performing a first seasoning process comprising;

reducing the flow of oxygen containing gas to the processing chamber while continuing to flow the inert gas and the nitrogen containing gas into the processing chamber; and

sputtering material from the sputtering target while the substrate remains in the processing chamber;

performing a second sputtering process comprising;

introducing the oxygen containing gas into the processing chamber along with the inert gas and the nitrogen containing gas; and

depositing a second layer having a second composition different than the first composition on the substrate that comprises oxygen, nitrogen, and one or more metals selected from the group consisting of zinc, cadmium, tin, indium, gallium, and combinations thereof.

16. The method of claim 15, further comprising performing a second seasoning process after the second sputtering process, comprising:

reducing the flow of oxygen containing gas to the processing chamber while continuing to flow the inert gas and the nitrogen containing gas into the processing chamber; and

sputtering material from the sputtering target while the substrate remains in the processing chamber.

17. The method of claim 16, further comprising performing a third seasoning process before the first sputtering process, comprising:

reducing the flow of oxygen containing gas to the processing chamber while continuing to flow the inert gas and the nitrogen containing gas into the processing chamber; and

sputtering material from the sputtering target while the substrate remains in the processing chamber.

18. The method of claim 17, wherein substantially no material deposited on the substrate during the third seasoning process.

19. The method of claim 17, wherein the nitrogen containing gas comprises N₂.

20. The method of claim 19, wherein the oxygen containing gas comprises N₂O.