Resistive memory

#The present disclosure relates generally to the field of semiconductor memory. More particularly, in one or more embodiments the present disclosure relates to a resistive memory and methods of operating resistive memory.

#Memory devices are typically provided as internal, semiconductor, integrated circuits in computers or other electronic devices. There are many different types of memory including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), flash memory, and resistive random access memory (RRAM), such as magnetoresistive random access memory (MRAM; also referred to as magnetic random access memory) among others.

#Memory devices are utilized as non-volatile memory for a wide range of electronic applications in need of high memory densities, high reliability, and low power consumption. Non-volatile memory may be used in a personal computer, a portable memory stick, a solid state drive (SSD), a personal digital assistant (PDA), a digital camera, a cellular telephone, a portable music player (e.g., MP3 player), a movie player, and other electronic devices, among others. Program code and system data, such as a basic input/output system (BIOS), are typically stored in non-volatile memory devices.

#FIG. 1 is a functional block diagram of a non-volatile memory in accordance with one or more embodiments of the present disclosure.

#FIG. 2A illustrates an example magnetic structure in a low resistance state in accordance with one or more embodiments of the present disclosure.

#FIG. 2B illustrates an example magnetic structure in a high resistance state in accordance with one or more embodiments of the present disclosure.

#The present disclosure includes resistive memory devices and systems having resistive memory cells, as well as methods for operating the resistive memory cells. One memory device embodiment includes at least one resistive memory element, a programming circuit, and a sensing circuit. For example, the programming circuit can include a switch configured to select one of N programming currents for programming the at least one resistive memory element, where each of the N programming currents has a unique combination of current direction and magnitude, with N corresponding to the number of resistance states of the at least one memory element. In one or more embodiments, the sensing circuit can be arranged for sensing of the N resistance states.

#The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example, 102 may reference element “02” in FIG. 1, and a similar element may be referenced as 202A in FIGS. 2A and 302 in FIG. 3, etc.

#FIG. 1 is a functional block diagram of a non-volatile memory 100 in accordance with one or more embodiments of the present disclosure. As shown in FIG. 1, a resistive memory element 102 may be formed by a magnetic structure (e.g., magnetic spin valve, magnetic tunnel junction (MTJ)). The magnetic structure can include a pinned layer 104 and free layer 106 separated by a tunnel barrier 108. Resistive memory element 102 has a first terminal 114 and a second terminal 118. While FIG. 1 shows the first terminal 114 directly coupled to the free layer 106, and the second terminal 118 directly coupled to the pinned layer 104, embodiments of the present disclosure are not so limited. For example, embodiments of the present disclose may be implemented with additional layers and/or features (e.g., a discrete anti-magnetic layer), which are omitted from FIG. 1 for clarity.