Magnetic spin shift register memory

• US 8,467,221 B2
• Filed: 07/09/2010
• Issued: 06/18/2013
• Est. Priority Date: 07/09/2010
• Status: Expired due to Fees

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Joseph, Eric A., Parkin, Stuart S. P., Rothwell, Mary B.
• Primary Examiner(s): Ho, Hoai V
• Assistant Examiner(s): Huang, Min
• Application Number:
  US12/833,446
• Publication Number:
  US 20120008362A1
• Time in Patent Office: 1,075 Days
• Field of Search: 365/80
• US Class Current: 365/80
• CPC Class Codes: G11C 11/14 using thin-film elements
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 19/0808 using magnetic domain propagation

Abstract

A method for forming a memory device includes forming a cavity having an inner surface with an undulating profile in a substrate, depositing a ferromagnetic material in the cavity, forming a reading element on the substrate proximate to a portion of the ferromagnetic material, and forming a writing element on the substrate proximate to a second portion of the ferromagnetic material.

Claims

1. A memory device comprising:

a shift register including a ferromagnetic material disposed in a cavity having an undulating inner surface profile, wherein the cavity is formed by alternating isotropic etching and passive polymer deposition processes and wherein a depth of the cavity is determined by a number of isotropic etching and passive polymer deposition process cycles;

a reading element disposed proximal to a portion of the shift register; and

a writing element disposed proximal to a second portion of the shift register.

2. The device of claim 1, wherein the undulating inner surface profile of the cavity defines domain walls defining magnetic domains in the ferromagnetic material.

3. The device of claim 1, wherein the undulating inner surface profile includes rib portions.

4. The device of claim 1, wherein the undulating inner surface profile is scalloped shaped.

5. The device of claim 1, wherein the shift register is operative to store data.