# Presentation: 033265

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

- Dr. H. Grube, Dr. A.C. Perrella#
-  #recently deceased

- *joshua.pomeroy@nist.gov

- Advanced materials synthesis for spin-based electronics (a new process approach to hard drive read heads)

## 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

## 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

## Hard drives: Three important pieces

- Write – Get information onto “paper”			OK
- Retain – “Paper” must last a long time		OK
- Read – Have to restore the information	Challenges

- Materials Research Society Bulletin **31** p. 379

## Resistance Area product

- Engineers like resistance to stay the same, even if size (area) changes, therefore, need adjustable RA product

- _Resistance x Area (RA) -_resistance property of layered materials
- For the same layers –
- 1⁄2 area = 2 x Resistance
- _Resistance x Capacitance (RC)_
- 	speed; large RC = slow

- 1⁄2 A x 2 R = RA

-  A x R = RA

## Two “Read” sensors – RA product limitation

- Low resistance metal based **CPP-GMR type sensors**
- 	(metal/metal/metal layer structures)
- 				RA ~ mm2
- **Problem: very small signal**!
- High resistance insulator  based **MTJ  type sensors**
**	**(metal/insulator/metal layer structures)** **
- 				RA ~ Mm2
- 		        **Problem: too slow (RC too big)!**

## Modified Oxides Magnetic Sensors

- Industry Need: Continuously variable RA for a single sensor design with useable MR (signal strength).

## 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.

## Huge RA product range from one recipe

- Using conventional strategies, each data point would require the development of a new recipe—a huge expense!

- All points produced
- from one recipe

## Modified Oxide Read Sensor Performance 

- Modified Oxide Read Sensor Performance

- MR > 20%
- (good signal)

- NIST process is compatible with working “read” sensors

**Notes:**
Likely scenarios

## 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.