Dr. Joshua M. Pomeroy*, Dr. H. Grube, Dr. A.C. Perrella # #recently deceased

1. (1) (2) (3) Advanced materials synthesis for spin-based electronics (a new process approach to hard drive read heads) Dr. Joshua M. Pomeroy*, Dr. H. Grube, Dr. A.C. Perrella# #recently deceased *joshua.pomeroy@nist.gov

2. Motivating Objective Electronic device performance can be improved by producing materials with “ideal” properties that are not intrinsic to known materials One strategy is to seek new, “undiscovered” materials with specific properties Alternatively, NIST process constructs combinations of known materials such that the “hybrids” have properties not native to the constituents

3. MRS Bulletin 31 p. 375 Specific Market Opportunity “Moore’s Law” of Magnetic Recording (hard drives) We want more storage capacity, but physically smaller hard drives Literally EVERY computer sold has a hard drive

4. Hard drives:Three important pieces Materials Research Society Bulletin 31 p. 379 • Write – Get information onto “paper” OK • Retain – “Paper” must last a long time OK • Read – Have to restore the informationChallenges

5. Resistance Area product Resistance x Area (RA) -resistance property of layered materials For the same layers – ½ area = 2 x Resistance Resistance x Capacitance (RC) speed; large RC = slow A x R = RA ½ A x 2 R = RA Engineers like resistance to stay the same, even if size (area) changes, therefore, need adjustable RA product

6. Two “Read” sensors – RA product limitation • Low resistance metal based CPP-GMR type sensors (metal/metal/metal layer structures) RA ~ m mm2 Problem: very small signal! • High resistance insulator based MTJ type sensors (metal/insulator/metal layer structures) RA ~ M mm2 Problem: too slow (RC too big)!

7. GMR HCIMO MTJ • Quality Oxides with variable resistance • All metallic • Low RA product (1-10 mΩ●μm2) • Uses insulators • High RA product (10+ Ω●μm2) Ferromagnet Ferromagnet Ferromagnet Metal Spacer Insulating Barrier Ferromagnet Ferromagnet Ferromagnet 10-3 10-2 10-1 1 10 100 RA (Ω mm2) Modified Oxides Magnetic Sensors • Industry Need: Continuously variable RA for a single sensor design with useable MR (signal strength).

8. (1) (2) (3) Overview of Method • Build the “base” of the electronic device by depositing electrodes and an insulating layer • Expose the insulating layer to highly charged ions (Coulomb bombs) – creating small, individual “craters” in the insulator • Deposit upper device structure over the irradiated insulator, thereby filling the craters with metal • The layer that was initially an insulator becomes a combination of metal and insulator Patent Pending – Application #12/036,729 – licensing opportunities available.

9. Huge RA product range from one recipe All points produced from one recipe Using conventional strategies, each data point would require the development of a new recipe—a huge expense!

10. Modified Oxide Read Sensor Performance MR > 20% (good signal) NIST process is compatible with working “read” sensors

11. Product Development Opportunities • Specific market opportunity – NIST process provides variable-RA “read” sensors like those required for high density hard drive sensor packages – requires a “tool” • This example also maps to MRAM industry, and other resistance based sensor markets • While the ultimate customer is likely a large magnetic storage company, individual process tools are developed and provided by a wide range of smaller companies Patent Application #12/036,729 – licensing opportunities available.