Magnetic memory device having a C-shaped structure and method of manufacturing the same

• US 20090146231A1
• Filed: 11/07/2008
• Published: 06/11/2009
• Est. Priority Date: 12/05/2007
• Status: Abandoned Application

• Current Assignee: MicroMed Technology, Inc (MicroMed Cardiovascular, Inc.)
• Original Assignee: MicroMed Technology, Inc (MicroMed Cardiovascular, Inc.)
• Inventors: Imai, Darren, Kuper, Cynthia A.
• Application Number:
  US12/289,951
• Publication Number:
  US 20090146231A1
• Time in Patent Office: Days
• US Class Current: 257/421
• CPC Class Codes: G01R 33/07 Hall effect devices
• CPC Class Codes: G11C 11/18 using Hall-effect devices

Abstract

A non-volatile magnetic memory device having one or more memory cells, each of the memory cells includes a magnetic switch including a C-shaped magnetic component and a write coil located proximate the magnetic component, the write coil coupled to receive a current sufficient to create a remnant magnetic polarity in the magnetic component, and a Hall sensor, positioned proximate the magnetic component, to detect the remnant magnetic polarity indicative of a stored data bit.

Claims

1. A memory device, comprising:

a first magnetic portion of a memory bit;

a sensor formed over the first magnetic portion; and

a second magnetic portion of the memory bit formed above the sensor,

wherein the first and second magnetic portions are connected by a third magnetic portion.

2. The memory device of claim 1, wherein a coil is disposed coaxially around the third magnetic portion.

3. The memory device of claim 2, wherein the coil includes a plurality of coil layers.

4. The memory device of claim 1, wherein the first, second and third magnetic portions are made of a soft magnetic material, such as 80:

20 NiFe, 45;

55 NiFe, or NiFeCo.

5. The memory device of claim 1, wherein the sensor is made from a high electron mobility material, such as GaAs, InP, or a 2DEG composite.

6. The memory device of claim 1, wherein the sensor is made from SiGe.

7. A method of fabricating the memory device of claim 1, that incorporates the use of magnetic pillars to direct the magnetic flux around the magnetic storage device, which reduces the amount of stray magnetic fields, reducing cross-talk with adjacent bits, and strengthens the magnetic flux at the sensor by the reduction of losses.

8. A method of fabricating the memory device of claim 1 that incorporates the use of copper damascene procedures to form the coils.

9. A method of fabricating the memory device of claim 1 that utilizes the metal (aluminum) from one of the metallization layers of a CMOS device to form the coils.

10. A method of fabricating a memory device, comprising:

forming an amorphous GaAs layer over a silicon substrate;

annealing the amorphous GaAs layer; and

forming a crystalline GaAs layer on the amorphous layer.

11. A method of fabricating a memory device, which utilizes ion implant to isolate the sensor, replacing wet chemical etching, allowing for smaller sensor dimensions.