Current-Driven Domain Wall Dynamics in Magnetic …
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Fig. 32 Scanning electron microscope (SEM) image of the devices for the data retention experiments. 240 wires were fabricated on each device to calculate the statistical distribution of the data
error. The zoom-in image of a row of wires is shown. The π-shaped strip-line is used to inject the
DWs in the wire using a pulse generator. Using this method, the DWs in all the wire of a row are
injected in a single pulse
where K B is the Boltzmann factor and T is the absolute temperature. The magnetic
devices are required to retain the data for at-least 10 years at operating temperature
ranging from 80 to 120 °C. In this section, we discuss the data retention and thermal
stability experiments in SAF based DW memory devices.
The SAF thin film stacks patterned into several wires using EBL and ion-milling
techniques are shown in Fig. 32. In each device, 240 wires are patterned to calculate
the statistical distribution of errors in the data. Cu/Au lines are also fabricated at the
edge of each wire to inject the DWs by applying electrical pulses. After successful
injection of DWs in the wires, the DWs are driven towards the center of wires using
pulsed magnetic field. The positions of the DWs can imaged using Kerr microscopy
as shown in Fig. 33. The devices are then baked at various temperatures over a range
of time spans. During the baking, the devices are mounted on glass slides which was
kept inside an oven. Positions of the DWs in the wires in the post-baked devices are
measured using the Kerr microscopy.
The temperature excites the magnetic moments and causes the DWs to displace
from their original positions. The displacements in the DWs position were measured
by using Kerr microscopy. Kerr images of a device before and after baking at 210 °C
for 23 h, are shown in Fig. 33a and b, respectively. A visible displacement of the
DW in a wire is marked in the yellow circle. The wires were divided into sub-cells
of 500 nm along the length for accurate measurements of the DWs displacement.
137
Fig. 32 Scanning electron microscope (SEM) image of the devices for the data retention experiments. 240 wires were fabricated on each device to calculate the statistical distribution of the data
error. The zoom-in image of a row of wires is shown. The π-shaped strip-line is used to inject the
DWs in the wire using a pulse generator. Using this method, the DWs in all the wire of a row are
injected in a single pulse
where K B is the Boltzmann factor and T is the absolute temperature. The magnetic
devices are required to retain the data for at-least 10 years at operating temperature
ranging from 80 to 120 °C. In this section, we discuss the data retention and thermal
stability experiments in SAF based DW memory devices.
The SAF thin film stacks patterned into several wires using EBL and ion-milling
techniques are shown in Fig. 32. In each device, 240 wires are patterned to calculate
the statistical distribution of errors in the data. Cu/Au lines are also fabricated at the
edge of each wire to inject the DWs by applying electrical pulses. After successful
injection of DWs in the wires, the DWs are driven towards the center of wires using
pulsed magnetic field. The positions of the DWs can imaged using Kerr microscopy
as shown in Fig. 33. The devices are then baked at various temperatures over a range
of time spans. During the baking, the devices are mounted on glass slides which was
kept inside an oven. Positions of the DWs in the wires in the post-baked devices are
measured using the Kerr microscopy.
The temperature excites the magnetic moments and causes the DWs to displace
from their original positions. The displacements in the DWs position were measured
by using Kerr microscopy. Kerr images of a device before and after baking at 210 °C
for 23 h, are shown in Fig. 33a and b, respectively. A visible displacement of the
DW in a wire is marked in the yellow circle. The wires were divided into sub-cells
of 500 nm along the length for accurate measurements of the DWs displacement.