VARYING ENERGY BARRIERS OF MAGNETIC TUNNEL JUNCTIONS (MTJs) IN DIFFERENT MAGNETO-RESISTIVE RANDOM ACCESS MEMORY (MRAM) ARRAYS IN A SEMICONDUCTOR DIE TO FACILITATE USE OF MRAM FOR DIFFERENT MEMORY APPLICATIONS

Abstract

Varying energy barriers of magnetic tunnel junctions (MTJs) in different magneto-resistive random access memory (MRAM) arrays in a semiconductor die to facilitate use of MRAM for different memory applications is disclosed. In one aspect, energy barriers of MTJs in different MRAM arrays are varied. The energy barrier of an MTJ affects its write performance as the amount of switching current required to switch the magnetic orientation of a free layer of the MTJ is a function of its energy barrier. Thus, by varying the energy barriers of the MTJs in different MRAM arrays in a semiconductor die, different MRAM arrays may be used for different types of memory provided in the semiconductor die while still achieving distinct performance specifications. The energy barrier of an MTJ can be varied by varying the materials, heights, widths, and / or other characteristics of MTJ stacks.

Description

BACKGROUNDI. Field of the Disclosure[0001]The technology of the disclosure relates generally to magneto-resistive random access memory (MRAM), and more particularly to magnetic tunnel junctions (MTJs) employed in MRAM.II. Background[0002]Semiconductor storage devices are used in integrated circuits (ICs) in electronic devices to provide data storage. One example of a semiconductor storage device is magneto-resistive random access memory (MRAM). MRAM is non-volatile memory in which data is stored by programming a magnetic tunnel junction (MTJ) as part of an MRAM bit cell. One advantage of MRAM is that MTJs in MRAM bit cells can retain stored information even when power is turned off. This is because data is stored in the MTJ as a small magnetic element rather than as an electric charge or current.[0003]In this regard, an MTJ comprises a free ferromagnetic layer (“free layer”) disposed above or below a fixed or pinned ferromagnetic layer (“pinned layer”). The free and pinned layers ar...

AI Technical Summary

Benefits of technology

This patent describes a way to make MTJs (the part of a memory device) with different energy barriers in the same layer of a semiconductor die. This is done by depositing layers of a material over the semiconductor die and then removing some of them to create different MTJs with different energy barriers. This allows for the creation of memory devices with different performance specifications in the same layer. The technical effect of this invention is the possibility of creating more complex memory devices in a more efficient way.

Problems solved by technology

Different memory applications may require different tradeoffs between access times and data retention performance as an example, where using MTJ stacks having the same energy barrier in these different memory applications may not allow the desired differences in performance to be realized.

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