M-RAM
The Perfect Memory

Most PC's today use a D- RAM, a dynamic random access memory. The one drawback this has is that its memory can hold on only as long as it is nourished by electricity. However, we just might have a better substitute for the D-RAM. Research in this field seems to lead to M-RAM, memory that can store data without a power supply.

M-RAM, magnetic random access memory makes use of miniscule magnets to store the 0's and 1's of binary data. This actually cuts down power consumption drastically. With all major memory producers conducting research in this field, the new memory chip may hit the market by 2005.

According to Jeff Mailloux, director of D-RAM marketing at Micron, D-RAM is the perfect memory. As things stand today introducing the new advanced chip is not the big deal; the task ahead is to make it cost effective.

This new technology is a spin-off of advanced research in the field of Spin electronics or spintronics. Spin, the essential quantum property of an electron, behaves akin a magnet. By aligning or polarising these tiny magnets to go in a uniform pattern they can be used to signify the elements of the binary code. This exploitation of the spins can be stretched to cover the area of memory as well.

M-RAM magnetically stores its information so that it remains largely unaffected by any loss of power. This magnetic structure moreover is the least battery exhaustive thereby making it highly ideal for wireless and portable devices.

Since the last five years this realm of research has been totally funded by the government. However henceforth companies are to take it on their own. Consequently IBM has entered into an agreement with Infineon Technologies to develop M-RAM products. The solid state IBM memory unit comprises of a lattice of electrodes having ferro magnetic sandwiches at every intersection. Memory units rely on affecting polarity changes in the magnetic state within the sandwiches. Channelling them to bring about uniform behaviour when functioning at the atomic scale is the challenging task ahead. To change the polarity, a current is applied through the metal sandwiches that comprise the memory elements. The process is made more tough when these memory elements scale down or become smaller. Effectively maintaining the switching of the magnetic elements at the extremely small dimensions is still being worked out.

M-RAM may be effectively scaled down as initial studies prove which is probably why it has generated so much of interest and attention. Moreover in the coming years the feature size of a transistor is likely to come down to 100 nanometres. This may call for a memory chip that fits the size. Shrinking a D-RAM may deprive it further, reducing it to a weak device. This is where the M-RAM steps in.

One organisation actively involved in the study of M-RAM and its power to supplant existing memory chips is Motorola. They are pursuing their aim to replace the flash memory, D-RAM, ferro magnetic RAM, and static RAM with the M-RAM. With this end in view they have developed as a prototype a 256K M-RAM unit that is 256,000 storage bits integrated onto a standard silicon chip. This is the largest M-RAM built or demonstrated so far. They are further trying to integrate this M-RAM with their existing logic to extend its application to wireless and automotive devices. Today the capacity of a D-RAM is 256 megabits which is higher than that of the Motorola model but in the coming years the M-RAM is sure to surpass it by its sheer ability to scale down to ultimate dimensions.

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