Deposition of perovskite and other compound ceramic films for dielectric applications

• US 20070053139A1
• Filed: 09/02/2005
• Published: 03/08/2007
• Est. Priority Date: 09/02/2005
• Status: Active Grant

• Current Assignee: Demaray LLC
• Original Assignee: Springworks, LLC (Petters Group Worldwide LLC)
• Inventors: Zhang, Hongmei, Demaray, Richard
• Granted Patent: US 7,838,133 B2
• Time in Patent Office: Days
• US Class Current: 361/311
• 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 perovskite layer on a substrate, comprising:

placing the substrate into a reactor;

flowing a gaseous mixture through the reactor; and

providing power to a target formed of a perovskite material positioned opposite the substrate.

2. The method of claim 1, wherein providing power to the conducting target includes applying pulsed-DC power to the conducting target.

3. The method of claim 2 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.

4. The method of claim 2, further including supplying an RF bias power to the substrate.

5. The method of claim 1, wherein providing power to the conducting target includes applying RF power to the conducting target.

6. The method of claim 1, wherein a perovskite layer is formed on the substrate.

7. The method of claim 6, wherein the perovskite layer is a barium strontium titanite (BST) layer.

8. The method of claim 6, wherein the formed perovskite layer is more than about 0.1 micron thick.

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

10. The method of claim 6, further comprising annealing the perovskite layer formed on the substrate.

11. The method of claim 10 wherein annealing the perovskite layer includes heating the perovskite layer to an anneal temperature of between about 500°

C. and about 800°

C.

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

13. The method of claim 12, wherein preheating the substrate including heating the substrate to a temperature of about 400°

C. for low temperature perovskite deposition.

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

15. The method of claim 14, wherein the low temperature substrate is one of a set of substrates including glass, plastic, metal foil, copper, and stainless steel.

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

17. The method of claim 16 wherein the target is doped with Manganese.

18. The method of claim 17 wherein a level of Manganese in the target is at least 0.1%.

19. The method of claim 1, wherein the perovskite target is a conductive target.

20. A capacitor structure, comprising:

a first conducting electrode layer;

a dielectric perovskite layer deposited over the first conducting electrode layer; and

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

21. The capacitor of claim 20, wherein the first conducting layer is a copper sheet.

22. A stacked capacitor structure, comprising:

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

a bottom electrode layer,

a dielectric perovskite layer deposited over the electrode layer, and

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

23. The stacked capacitor structure of claim 22, wherein the capacitor stacks form a parallel stacked capacitor structure.

24. The stacked capacitor structure of claim 22, wherein the capacitor stacks form a series stacked capacitor structure.

25. A method of producing a capacitor, comprising:

loading a substrate into a cluster tool;

depositing a dielectric perovskite layer over a substrate in a chamber of the cluster tool.

26. The method of claim 25, wherein depositing the dielectric perovskite layer includes depositing perovskite film with a pulsed-DC PVD process.

27. The method of claim 25, wherein depositing the dielectric perovskite layer includes depositing perovskite film with an RF sputtering PVD process.

28. The method of claim 25, wherein depositing the dielectric perovskite layer includes depositing the perovskite material through a mask.

29. The method of claim 25, further including

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

31. The method of claim 25, further including depositing a top electrode layer over the dielectric perovskite layer.

32. A fixture for holding a thin substrate, comprising:

a top portion; and

a bottom portion, wherein

the thin substrate is held when the top portion is attached to the bottom portion.