Ultra high vacuum deposition of PCMO material

• US 20080011603A1
• Filed: 07/14/2006
• Published: 01/17/2008
• Est. Priority Date: 07/14/2006
• Status: Abandoned Application

• Current Assignee: 4D-S Pty, Ltd.
• Original Assignee: 4D-S Pty, Ltd.
• Inventors: Nagashima, Makoto
• Application Number:
  US11/486,473
• Publication Number:
  US 20080011603A1
• Time in Patent Office: Days
• US Class Current: 204/192.25
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/087 of copper or solid solutions thereof
• CPC Class Codes: C23C 14/352 using more than one target C23C14/56 takes precedence
• CPC Class Codes: H01F 1/407 Diluted non-magnetic ions in a magnetic cation-sublattice, e.g. perovskites, La1-x(Ba,Sr)xMnO3
• CPC Class Codes: H01J 37/3405 Magnetron sputtering
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

Systems and methods are disclosed to form an exemplary memory structure by forming patterned semiconductor structures on a wafer; moving the wafer to a back-biased FTS deposition chamber; providing ultra high vacuum condition; and depositing PCMO material on patterned semiconductor structure.

Claims

1. A method for forming a semiconductor, comprising:

forming a low oxygen YBa₂Cu₃O₇ (Y-123) on Pr_0.67Ca_0.33MnO₃ (PCMO) layer;

forming an intermediate oxygen PCMO layer above the low oxygen PCMO layer; and

forming a high oxygen PCMO layer above the intermediate oxygen PCMO layer.

2. The method of claim 1, comprising forming a memory device.

3. The method of claim 1, wherein the first oxygen-rich PCMO structure comprises a layer of approximately 200 Å

.

4. The method of claim 1, wherein the oxygen-deficient PCMO structure comprises a layer of approximately 1,200 Å

.

5. The method of claim 1, wherein the second oxygen-rich PCMO structure comprises a layer of approximately 200 Å

.

6. The method of claim 1, comprising depositing materials using a medium radio frequency (RF) rate of at least 100 kilohertz.

7. The method of claim 1, wherein the oxygen flow is about 25%.

8. The method of claim 1, wherein the temperature is 360 degrees Celsius or less.

9. The method of claim 1, wherein the temperature is 340 degrees Celsius or less.

10. The method of claim 1, comprising:

providing at least one target and a substrate having a film-forming surface portion and a back portion;

creating a magnetic field so that the film-forming surface portion is placed in the magnetic field with the magnetic field induced normal to the substrate surface portion;

back-biasing the back portion of the substrate;

maintaining a temperature at 380 degrees Celsius or less, a back-bias greater than 80 volts, and an oxygen flow of at least 17%; and

sputtering material onto the film-forming surface portion, wherein the thin forming surface portion comprises non-volatile data storage devices interconnected thereto.

11. A facing targets sputtering device for semiconductor fabrication, comprising:

an air-tight chamber in which an inert gas is admittable and exhaustible;

a pair of target plates placed at opposite ends of said air-tight chamber respectively so as to face each other and form a plasma region therebetween;

a pair of magnets respectively disposed adjacent to said target plates such that magnet poles of different polarities face each other across said plasma region thereby to establish a magnetic field of said plasma region between said target plates;

a substrate holder disposed adjacent to said plasma region, said substrate holder adapted to hold a substrate on which an alloyed thin film is to be deposited;

a back-bias power supply coupled to the substrate holder;

wherein the chamber temperature is maintained at 380 degrees Celsius or less, a back-bias voltage greater than 80 volts, and an oxygen flow of at least 17%;

forming a first oxygen-rich YBa₂Cu₃O₇ (Y-123) on Pr_0.67Ca_0.33MnO₃ (PCMO) layer;

forming an oxygent-deficit PCMO layer above the first oxygen rich PCMO layer; and

forming a second oxygen-rich PCMO layer above the oxygen deficit PCMO layer.

12. A facing targets sputtering device according to claim 11, comprising a first target power supply coupled to one of the target plates and wherein the first target power supply is a DC or an AC electric power source.

13. A facing targets sputtering device according to claim 11, comprising a second target power supply coupled to the remaining target plate, wherein the first and second target power supplies comprises DC and AC electric power sources.

14. A facing targets sputtering device according to claim 11, comprising a magnetron coupled to the chamber.

15. A facing targets sputtering device according to claim 11, comprising a chuck heater mounted above the wafer.

16. A facing targets sputtering device according to claim 11, wherein the substrate comprises an amorphous crystalline structure formed above a metal layer.

17. A facing targets sputtering device according to claim 16, wherein the substrate comprises a crystalline structure above the amorphous crystalline structure.

18. A facing targets sputtering device according to claim 11, wherein materials are deposited at a medium radio frequency (RF) rate of at least 100 kilohertz.

19. A facing targets sputtering device according to claim 11, wherein the oxygen flow is 25% or less.

20. A method to form a memory device, comprising:

forming patterned semiconductor structures on a wafer;

moving the wafer to a back-biased FTS deposition chamber;

providing ultra high vacuum condition; and

depositing PCMO material on patterned semiconductor structure.