Thermal Characterization of the 144 nm GMR Layer Using Microfabricated Suspended Structures

2003 ◽  
Author(s):  
Shu Zhang ◽  
Yizhang Yang ◽  
Sadegh M. Sadeghipour ◽  
Mehdi Asheghi
Keyword(s):  
Temperature Rise ◽  
Electrostatic Discharge ◽  
Thermal Characterization ◽  
Normal Operation ◽  
Maximum Temperature ◽  
Multilayer Structures ◽  
Accurate Knowledge ◽  
Gmr Sensor ◽  
Present Effort

The performance and reliability of GMR heads are influenced by the level of temperature rise, which may occur in the device during the normal operation or during an electrostatic discharge (ESD) event. However, the reliable electro-thermal modeling of the GMR sensor to predict the temperature rise, demands an accurate knowledge of the thermal properties of its constituent materials such as Al2O3 passivation and GMR layers. The lateral thermal conductivity of the GMR layer, which has not been measured previously, can largely influence the maximum temperature rise in the GMR sensor. The present effort will be directed at thermal characterization of the CoFe/Cu multilayer structures made of extremely thin periodic layers, using steady-state and frequency domain heating and thermometry in suspended bridges. The measurements are performed on several suspended structures with the lengths and widths in the range of 250 to 500 μm and 16 to 20 μm, respectively.

Self-Heating Modeling of Magnetic Recording Read Head

2005 ◽  
Author(s):  
Y. Yang ◽  
L. Baril ◽  
E. Schreck ◽  
A. Wallash ◽  
M. Asheghi
Keyword(s):  
Magnetic Recording ◽  
Temperature Rise ◽  
Areal Density ◽  
Technical Conference ◽  
Normal Operation ◽  
Electronic Systems ◽  
Element Analysis ◽  
Self Heating ◽  
Read Head ◽  
Gmr Sensor

The performance and reliability of the GMR heads are adversely affected by self-heating due to the aggressive scaling of its dimensions to increase areal density. In this manuscript, the self-heating of the GMR head during the normal operation is investigated. An analytical model is developed to estimate the temperature rise in the GMR sensor due to self-heating for magnetic recording areal densities from 2.8 to 80 Gbits/in2, which agrees well with the FEM simulations. This model is subsequently used to investigate the influence of the GMR head constituent materials’ thermal properties on the device temperature rise. A 3-D finite element analysis was also performed to predict the level of self-heating in lead-overlaid (LOL) design, which agrees well with the experimental data obtained using steady-state and transient measurements.   This paper was also originally published as part of the Proceedings of the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems.

Thermal Characterization of Cu∕CoFe Multilayer for Giant Magnetoresistive Head Applications

2005 ◽  
Vol 128 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Y. Yang ◽  
R. M. White ◽  
M. Asheghi
Keyword(s):  
Electrical Resistance ◽  
Multilayer Structure ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Thermal Characterization ◽  
Disk Drive ◽  
Multilayer Structures ◽  
Large Decrease ◽  
Resistance Thermometry

Giant magnetoresistance (GMR) head technology is one of the latest advancements in the hard disk drive (HDD) storage industry. The GMR head multilayer structure consists of alternating layers of extremely thin metallic ferromagnetic and nonmagnetic films. A large decrease in the electrical resistivity from antiparallel to parallel alignment of the film magnetizations is observed, known as the GMR effect. The present work characterizes the in-plane electrical and thermal conductivities of Cu∕CoFe GMR multilayer structures in the temperature range of 50K to 340K using Joule-heating and electrical resistance thermometry on suspended bridges. The thermal conductivity of the GMR layer monotonically increases from 25Wm−1K−1 (at 55K) to nearly 50Wm−1K−1 (at room temperature). We also report a GMR ratio of 17% and a large magnetothermal resistance effect (GMTR) of 25% in the Cu∕CoFe multilayer structure.

Modeling of Temperature Rise in Giant Magnetoresistive (GMR) Sensor During an Electrostatic Discharge (ESD) Event

2003 ◽  
Author(s):  
Yizhang Yang ◽  
Sadegh M. Sadeghipour ◽  
Mehdi Asheghi
Keyword(s):  
Thermal Properties ◽  
Temperature Rise ◽  
Electrostatic Discharge ◽  
Thermal Response ◽  
Human Body Model ◽  
Element Analysis ◽  
Current Voltage ◽  
Source Current ◽  
Reliability Issue ◽  
Gmr Sensor

With the further miniaturization of the GMR heads, the electrostatic discharge (ESD) failure has become the primary reliability issue in manufacturing of these sensors. The Joule heating effect during the ESD events result in both thermal and magnetic damages in GMR heads. In this paper, the thermal response of the GMR read head to the excessive current/voltage during an ESD event is investigated numerically using a 3-D finite element analysis. Unlike the previous studies, the thermal properties of the GMR and Al2O3 gap layers used in the simulation are the experimentally measured values. The temperature-rise in GMR heads under human-body-model (HBM) source current is obtained for a range of GMR dimensions and thermal properties of its constituent materials. The simulation results show that temperature in the GMR element sharply increases as the GMR dimensions are reduced, indicating the future GMR heads are more susceptible to the ESD damages. In addition, thermal properties of the GMR and gap materials play key roles in accurate prediction of the temperature field in GMR head during ESD events.

Field-Dependent Electrical and Thermal Characterization of Cu/CoFe Multilayer for Giant Magnetoresistive (GMR) Head Applications

2005 ◽  
Author(s):  
Y. Yang ◽  
J.-G. Zhu ◽  
R. M. White ◽  
M. Asheghi
Keyword(s):  
Thermal Transport ◽  
Giant Magnetoresistance ◽  
Thermal Characterization ◽  
Disk Drive ◽  
Multilayer Structures ◽  
Thermal Transport Property ◽  
Superlattice Structure ◽  
Metallic Ferromagnet ◽  
Interfacial Scattering

Giant Magnetoresistance (GMR) head technology is one of the latest advancement in hard disk drive (HDD) storage industry. The GMR head superlattice structure consists of alternating layers of extremely thin metallic ferromagnet and paramagnet films. A large decrease in the resistivity from antiparallel to parallel alignment of the film magnetizations can be observed, known as giant magnetoresistance (GMR) effect (Baibich et al., 1988; Binasch et al., 1989). The GMR effect is generally due to the spin dependent electron bulk and interfacial scattering in the GMR multilayer structures (Zhang et al., 1992). However, in order to understand the nature of the spin-dependent electron scattering mechanism responsible for the GMR effect, both electrical and thermal transport properties of such multilayer structures must be measured and understood. It is suggested that the thermal transport property measurements in GMR can be used to judge whether the scattering processes responsible for the GMR have elastic and/or inelastic components (Shi et al., 1996). Moreover, the GMR effect is anticipated to have a thermal counterpart, known as giant magnetothermal resistance (GMTR) effect in which the thermal conductivity shows a ‘giant’ change under magnetic field.

Random pseudo promptings applied to the thermal characterization of a wet porous material

1999 ◽  
Vol 6 (1) ◽  
pp. 101-108 ◽  
Author(s):  
E. Delacre ◽  
D. Defer ◽  
E. Antczak ◽  
B. Duthoit
Keyword(s):  
Porous Material ◽  
Thermal Characterization

Photoacoustic thermal characterization of the dehydration process of Agar-SiO2emulsions

2005 ◽  
Vol 125 ◽  
pp. 177-180
Author(s):  
T. Lopez ◽  
M. Picquart ◽  
G. Aguirre ◽  
Y. Freile ◽  
D. H. Aguilar ◽  
...  
Keyword(s):  
Thermal Characterization ◽  
Dehydration Process
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