Methods of forming material over substrates

• US 20070252244A1
• Filed: 04/28/2006
• Published: 11/01/2007
• Est. Priority Date: 04/28/2006
• Status: Active Grant

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Rocklein, Noel, Korn, David, Vernon, John, Nelson, Jeff, Srividya, Cancheepuram, Gealy, F.
• Granted Patent: US 7,537,804 B2
• Time in Patent Office: Days
• US Class Current: 257/635
• CPC Class Codes: C23C 16/40 Oxides
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/3162 on a silicon body
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 28/40 Capacitors

Abstract

The invention includes ALD-type methods in which two or more different precursors are utilized with one or more reactants to form a material. In particular aspects, the precursors are hafnium and aluminum, the only reactant is ozone, and the material is hafnium oxide predominantly in a tetragonal crystalline phase.

Claims

1. A method of forming a material over a substrate, the method comprising utilization of at least one iteration an ALD-type pulse sequence comprising the pulse subsets M₂-M₁-R—

and M₁-(R-M₂-)_x;

where x is at least 2;

where M₁ is a first metal-containing precursor comprising a first metal, M₂ is a second metal-containing precursor comprising a second metal different from the first metal, and R is a reactant which reacts with one or both of the first and second metals;

where the material formed over the substrate comprises the first and second metals;

where at least a portion of the material is product from reaction of the reactant with one or both of the first and second metals; and

where the hyphen between pulses means that the second pulse directly follows the first pulse, with the term “

directly follows”

indicating that the second pulse either immediately follows the first pulse or that only a purge separates the first and second pulses.

2. The method of claim 1 where the pulse sequence comprises the pulse subsets M₂-M₁-R—

and M₁-(R-M₂-)_x in the shown order.

3. The method of claim 1 where at least one of the first and second metals is selected from the group consisting of aluminum, hafnium, lanthanides, niobium, tantalum, titanium, yttrium and zirconium.

4. The method of claim 1 where both of the first and second metals are selected from the group consisting of aluminum, hafnium, lanthanides, niobium, tantalum, titanium, yttrium and zirconium.

5. The method of claim 1 where one of the first and second metals is hafnium and the other is aluminum, and where an atomic ratio of hafnium to aluminum within the material is from 1:

1 to 20;

1.

6. The method of claim 5 where substantially all of the hafnium in the material is comprised by hafnium oxide, and where at least 80 volume percent of the hafnium oxide is in tetragonal phase.

7. The method of claim 5 where substantially all of the hafnium in the material is comprised by hafnium oxide, and where at least 90 volume percent of the hafnium oxide is in tetragonal phase.

8. The method of claim 1 where the pulse sequence is [M₁-(R-M₂-)_x]_y . . . M₁-[R-M₂-]zR;

where x and y are integers greater than 1 and can be the same as one another or different from one another; and

where z is an integer greater than 1 and can be the same as one or both of x and y or different.

9. The method of claim 8 where R is one or more of O₃, H₂O, NO and NH₃.

10. The method of claim 8 where R is O₃;

and where one of the first and second metals is aluminum and the other is hafnium.

11. The method of claim 8 where x, y and z are at least 3.

12-26. -26. (canceled)

27. A method of forming a material over a substrate, the method comprising utilization of at least one iteration an ALD-type pulse sequence comprising the pulse subsets R-M₁, R-M₂ and M₂-M₁-R;

where M₁ is a first metal-containing precursor comprising a first metal, M₂ is a second metal-containing precursor comprising a second metal different from the first metal, and R is a reactant which reacts with one or both of the first and second metals;

where the material formed over the substrate comprises the first and second metals; and

where at least a portion of the material is product from reaction of the reactant with one or both of the first and second metals.

28. The method of claim 27 where the pulse sequence comprises the pulse subsets R-M₁, R-M₂ and M₂-M₁-R in the listed order.

29. The method of claim 27 where the pulse sequence comprises the pulse subsets R-M₁, R-M₂ and M₂-M₁-R in an order other than the listed order.

30. The method of claim 27 where at least one of the first and second metals is selected from the group consisting of aluminum, hafnium, lanthanides, niobium, tantalum, titanium, yttrium and zirconium.

32. The method of claim 27 where one of the first and second metals is hafnium and the other is aluminum, and where an atomic ratio of hafnium to aluminum within the material is from 1:

1 to 20;

1.

33. The method of claim 32 where substantially all of the hafnium in the material is comprised by hafnium oxide, and where at least 80 volume percent of the hafnium oxide is in tetragonal phase.

34. The method of claim 32 where substantially all of the hafnium in the material is comprised by hafnium oxide, and where at least 90 volume percent of the hafnium oxide is in tetragonal phase.

31. (canceled)

35-43. -43. (canceled)

44. A method of forming a material over a substrate, comprising:

placing the substrate within a reaction chamber and, while the substrate is within the chamber, performing at least one iteration of the following sequence;

utilizing a pulse sequence of reactant followed by first precursor, where the first precursor directly follows the reactant into the reaction chamber, but is in the chamber at a different and substantially non-overlapping time than the reactant;

utilizing a pulse sequence of the reactant followed by second precursor, where the second precursor directly follows the reactant into the reaction chamber, but is in the chamber at a different and substantially non-overlapping time than the reactant, and where the second precursor is different than the first precursor;

providing another pulse of the second precursor within the reaction chamber and forming a substantially saturated monolayer comprising a second component from the second precursor;

removing substantially all of the second precursor from within the reaction chamber;

providing another pulse of the first precursor within the reaction chamber and integrating a first component from the first precursor within the substantially saturated monolayer;

removing substantially all of the first precursor from within the reaction chamber; and

exposing the substantially saturated monolayer to the reactant.

45. The method of claim 44 where at least one of the first and second components comprises Si or Ge, and wherein the reactant is ozone.

46. The method of claim 44 where the first and second components comprise metals selected from the group consisting of aluminum, hafnium, lanthanides, niobium, tantalum, titanium, yttrium and zirconium.

47. The method of claim 44 where the first and second components comprise aluminum and hafnium, respectively.

49. The method of claim 47 where the reactant is ozone.

48. (canceled)

50. A semiconductor construction, comprising:

a substrate; and

a dielectric material over the substrate, the dielectric material comprising;

a first layer consisting of aluminum oxide;

a second layer over the first layer, and consisting of one or both of hafnium oxide and zirconium oxide;

a third layer over the second layer, and consisting of a homogeneous mixture of aluminum oxide with one or both of hafnium oxide and zirconium oxide;

a fourth layer over the third layer and consisting of one or both of hafnium oxide and zirconium oxide; and

a fifth layer over the fourth layer, and consisting of aluminum oxide.

51. The construction of claim 50 where the second layer consists of hafnium oxide, the third layer consists of a homogenous mixture of aluminum oxide and hafnium oxide, and the fourth layer consists of hafnium oxide.

52. The construction of claim 51 where the dielectric material is at least 80 volume percent in tetragonal crystal phase.

53. The construction of claim 51 where the dielectric material is at least 90 volume percent in tetragonal crystal phase.

54. The construction of claim 51 where an atomic ratio of hafnium to aluminum within the dielectric material is from about 1:

1 to about 20;

1.

55. The construction of claim 50 further comprising a pair of capacitor electrodes capacitively coupled to one another through the dielectric material.