Deposition of perovskite and other compound ceramic films for dielectric applications

• US 7,838,133 B2
• Filed: 09/02/2005
• Issued: 11/23/2010
• Est. Priority Date: 09/02/2005
• Status: Expired due to Fees

• Current Assignee: Demaray LLC
• Original Assignee: Springworks, LLC (Petters Group Worldwide LLC)
• Inventors: Zhang, Hongmei, Demaray, Richard E.
• Primary Examiner(s): Austin, Aaron
• Application Number:
  US11/218,652
• Publication Number:
  US 20070053139A1
• Time in Patent Office: 1,908 Days
• Field of Search: None
• US Class Current: 428/701
• CPC Class Codes: C23C 14/088 of the type ABO3 with A representing alkali, alkaline earth metal or Pb and B representing a refractory or rare earth metal
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 14/50 Substrate holders
• CPC Class Codes: H01G 4/085 Vapour deposited
• CPC Class Codes: H01G 4/1227 based on alkaline earth titanates
• CPC Class Codes: H01G 4/30 Stacked capacitors H01G4/33 takes precedence
• CPC Class Codes: H01G 4/33 Thin- or thick-film capacitors thin- or thick-film circuits H01L27/00; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor H01L28/40
• CPC Class Codes: H01L 21/02197 the material having a perovskite structure, e.g. BaTiO3
• CPC Class Codes: H01L 21/02266 deposition by physical ablation of a target, e.g. sputtering, reactive sputtering, physical vapour deposition or pulsed laser deposition
• CPC Class Codes: H01L 21/31691 with perovskite structure

Abstract

In accordance with the present invention, deposition of perovskite material, for example barium strontium titanite (BST) film, by a pulsed-dc physical vapor deposition process or by an RF sputtering process is presented. Such a deposition can provide a high deposition rate deposition of a layer of perovskite. Some embodiments of the deposition address the need for high rate deposition of perovskite films, which can be utilized as a dielectric layer in capacitors, other energy storing devices and micro-electronic applications. Embodiments of the process according to the present invention can eliminate the high temperature (>700° C.) anneal step that is conventionally needed to crystallize the BST layer.

Claims

1. A method of depositing a crystalline perovskite layer on a substrate, comprising:

placing the substrate into a reactor;

flowing a gaseous mixture through the reactor;

providing pulsed DC power to a conducting ceramic target in the reactor through a narrow band rejection filter such that a voltage on the conducting ceramic target alternates between positive and negative voltages, wherein the conducting ceramic target is formed of a perovskite material and is positioned opposite the substrate;

providing, to the substrate, an RF bias power that corresponds to the narrow band rejection filter, wherein the crystalline perovskite layer is formed on the substrate without high temperature annealing.

2. The method of claim 1 further including filtering the pulsed-DC power to protect a pulsed DC power supply from a bias power while allowing passage of the pulsed DC power through the filter.

3. The method of claim 1, further including applying RF power to the conducting ceramic target.

4. The method of claim 1, wherein the perovskite layer is a barium strontium titanate (BST) layer.

5. The method of claim 1, wherein the formed crystalline perovskite layer is more than about 0.1 micron thick.

6. The method of claim 1 wherein the formed crystalline perovskite layer is less than about 1 micron thick.

7. The method of claim 1, further comprising annealing the crystalline perovskite layer formed on the substrate.

8. The method of claim 7 wherein annealing the crystalline perovskite layer includes heating the crystalline perovskite layer to an anneal temperature of between about 500°

C. and about 800°

C.

9. The method of claim 1, further comprising preheating the substrate before applying power to the conducting ceramic target.

10. The method of claim 9, wherein preheating the substrate includes heating the substrate to a temperature of about 400°

C. for low temperature perovskite deposition.

11. The method of claim 1, wherein the substrate is a low temperature substrate.

12. The method of claim 11, wherein the low temperature substrate is one of a set of substrates including glass, plastic, metal foil, copper, and stainless steel.

13. The method of claim 1 wherein the conducting ceramic target is doped with one or more of a transition metal dopant, transition element, lanthanide, and/or amphotaric elements.

14. The method of claim 13 wherein the conducting ceramic target is doped with Manganese.

15. The method of claim 14 wherein a level of Manganese in the conducting ceramic target is at least 0.1%.

16. The method of claim 1, wherein the conducting ceramic target is a perovskite target with a resistance of less than a megaohm.

17. A capacitor structure, comprising:

a first conducting electrode layer;

a crystalline dielectric perovskite layer deposited over the first conducting electrode layer, wherein the crystalline dielectric perovskite layer is formed without high temperature annealing by depositing a crystalline perovskite film in a pulsed DC reactive ion process with substrate bias, wherein a conducting ceramic target receives alternating negative and positive voltages from a narrow band rejection filter based on a frequency associated with the substrate bias; and

a second conducting electrode layer deposited over the crystalline dielectric perovskite layer.

18. The capacitor of claim 17, wherein the first conducting electrode layer is a copper sheet.

19. A stacked capacitor structure, comprising:

one or more capacitor stacks deposited on a substrate, wherein each capacitor stack comprises;

a bottom electrode layer,

a crystalline dielectric perovskite layer deposited over the bottom electrode layer without annealing, wherein the crystalline dielectric perovskite layer is formed by depositing a crystalline perovskite film in a pulsed DC reactive ion process with substrate bias, wherein a conducting ceramic target receives alternating negative and positive voltages from a narrow band rejection filter based on a frequency associated with the substrate bias, and

a top electrode layer deposited over the one or more capacitor stacks.

20. The stacked capacitor structure of claim 19, wherein the capacitor stacks form a parallel stacked capacitor structure.

21. The stacked capacitor structure of claim 19, wherein the capacitor stacks form a series stacked capacitor structure.

22. A method of producing a capacitor, comprising:

loading a substrate into a cluster tool;

depositing a crystalline dielectric perovskite layer over a substrate without high temperature annealing in a chamber of the cluster tool, wherein the crystalline dielectric perovskite layer is formed by depositing a crystalline perovskite film in a pulsed DC reactive ion process with substrate bias, wherein a conducting ceramic target receives alternating negative and positive voltages from a narrow band rejection filter based on a frequency associated with the substrate bias.

23. The method of claim 22, wherein depositing the crystalline dielectric perovskite layer includes depositing a crystalline perovskite film with an RF sputtering PVD process.

24. The method of claim 22, wherein depositing the crystalline dielectric perovskite layer includes depositing the crystalline perovskite material through a mask.

25. The method of claim 22, further including

depositing a bottom electrode layer on the substrate wherein the crystalline dielectric perovskite layer is deposited over the bottom electrode layer.

26. The method of claim 22, further including depositing a top electrode layer over the dielectric perovskite layer.