Wafer processing apparatus & methods for depositing cobalt silicide

• US 20060014388A1
• Filed: 09/12/2005
• Published: 01/19/2006
• Est. Priority Date: 06/10/2002
• Status: Abandoned Application

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Microelectronics Corporation
• Inventors: Lee, David, Lur, Water, Wang, Kuang-Chih
• Application Number:
  US11/224,863
• Publication Number:
  US 20060014388A1
• Time in Patent Office: Days
• US Class Current: 438/683
• CPC Class Codes: H01L 21/28052 the conductor comprising a silicide layer formed by the silicidation reaction of silicon with a metal layer formed by metal ion implantation H01L21/28044
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence
• CPC Class Codes: H01L 21/67167 surrounding a central transfer chamber
• CPC Class Codes: H01L 21/67184 characterized by the presence of more than one transfer chamber
• CPC Class Codes: H01L 29/665 using self aligned silicidation, i.e. salicide formation of conductive layers comprising silicides H01L21/28518
• CPC Class Codes: H01L 29/6656 using multiple spacer layers, e.g. multiple sidewall spacers
• CPC Class Codes: H01L 29/6659 with both lightly doped source and drain extensions and source and drain self-aligned to the sides of the gate, e.g. lightly doped drain [LDD] MOSFET, double diffused drain [DDD] MOSFET
• CPC Class Codes: H01L 29/7833 with lightly doped drain or source extension, e.g. LDD MOSFET's; DDD MOSFET's for thin film transistors H01L29/78618

Abstract

A cluster tool and a number of different processes for making a cobalt-silicide material are disclosed. Combinations of alloyed layers of Co—Ti—along with layers of Co—are arranged and heat treated so as to effectuate a silicide reaction. The resulting structures have extremely low resistance, and show little line width dependence, thus making them particularly attractive for use in semiconductor processing. A cluster tool is configured with appropriate sputter targets/heat assemblies to implement many of the needed operations for the silicide reactions, thus resulting in higher savings, productivity, etc.

Claims

1-23. -23. (canceled)

24. A cluster tool for performing semiconductor processing operations on a wafer, the cluster tool comprising:

(a) a load lock chamber for receiving the wafer; and

(b) a sputter chamber coupled to the load lock chamber so that the wafer can be transported without breaking vacuum, said sputter chamber being equipped with a cobalt alloy target for sputtering a target material on the wafer;

said sputter chamber being further configured such that it can be purged of oxygen and nitrogen prior to a sputtering operation;

(c) a heat annealing apparatus for heating the wafer at a rate and temperature sufficient to cause a silicide reaction between the sputtered target material and the wafer;

wherein the heat annealing apparatus is coupled to the sputter chamber so that the wafer is not exposed to a contaminant containing ambient between steps (b) and (c).

25. The cluster tool of claim 24, wherein said load lock chamber is used for outgassing of the wafer.

30-32. -32. (canceled)

33. A cluster tool for performing semiconductor processing operations on a wafer, the cluster tool comprising:

(a) a cleaning chamber adapted to remove oxide from the wafer;

(b) a first sputter chamber equipped with a cobalt target for sputtering a first target material on the wafer;

(c) a second sputter chamber equipped with a cobalt and refractory metal alloy target for sputtering a second target material on the wafer;

(d) a wafer handler for transporting the wafer so that it is not exposed to air at least between the first sputter chamber and second sputter chamber;

(e) a heat annealing apparatus integrated within the cluster tool for heating the wafer at a rate and temperature sufficient to cause a silicide reaction on the wafer;

wherein the heat annealing apparatus is adapted within the cluster tool so that the wafer is not exposed to a contaminant containing ambient between steps (d) and (e).

34. The cluster tool of claim 33, wherein the cleaning chamber uses a sputtering operation.

35. The cluster tool of claim 33, wherein the first target material includes between about 80-100 Angstroms of Cobalt.

36. The cluster tool of claim 33, wherein the refractory metal includes one or more of:

Ti, Ta, W, Mo, Zr, Hf and/or Nb.

37. The cluster tool of claim 33 wherein the heat annealing apparatus is integrated as part of said second sputter chamber.

38. The cluster tool of claim 33 wherein the heat annealing apparatus is located within a separate anneal chamber.

39. The cluster tool of claim 33, wherein a ternary target is used in said second sputter chamber to form an additional layer on said second target material.

40. The cluster tool of claim 33, wherein a ternary target is used in said second sputter chamber to form an additional layer on said second target material.

41. A cluster tool for performing semiconductor processing operations on a wafer, the cluster tool comprising:

(a) a cleaning chamber adapted to remove oxide from the wafer;

(b) a first sputter chamber equipped with a first metal target including cobalt and a refractory metal and configured to sputter a first target material on the wafer;

(c) a second sputter chamber equipped with a second metal target and configured to sputter a second target material on said first target material, which second target material has a higher concentration of cobalt than a layer formed on the wafer by said first target material;

wherein the second sputter chamber includes an integrated heater to facilitate formation of Co2Si and/or CoSi during sputtering;

(d) a wafer handler for transporting the wafer so that it is not exposed to air at least between the first sputter chamber and second sputter chamber.

42. The cluster tool of claim 41, wherein said first target material is used to form a layer of about 5 to 15 nm on the wafer.

43. The cluster tool of claim 41, wherein said second metal target includes only Cobalt.

44. The cluster tool of claim 41, wherein said first metal target includes a concentration of said refractory metal in excess of 50 atomic percent.

45. The cluster tool of claim 41, further including a heat annealing apparatus integrated within the cluster tool for heating the wafer at a rate and temperature sufficient to cause a silicide reaction on the wafer.

46. The cluster tool of claim 45 wherein the heat annealing apparatus is adapted within the cluster tool so that the wafer is not exposed to a contaminant containing ambient.