Bipolar multistate nonvolatile memory

摘要

Embodiments generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has an improved device switching capacity by using multiple layers of variable resistance layers. In one embodiment, the resistive switching element comprises at least three layers of variable resistance materials to increase the number of logic states. Each variable resistance layer may have an associated high resistance state and an associated low resistance state. As the resistance of each variable resistance layer determines the digital data bit that is stored, the multiple variable resistance layers per memory element allows for additional data storage without the need to further increase the density of nonvolatile memory devices. Typically, resistive switching memory elements may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices, such as digital cameras, mobile telephones, handheld computers, and music players.

主权项

1. A method comprising:
forming a first layer operable as a first variable resistance layer; forming a second layer operable as a second variable resistance layer; and forming a third layer operable as a third variable resistance layer; wherein the first layer, the second layer, and the third layer are interconnected in series, wherein the first layer is configured to switch between a first low resistance state and a first high resistive state, wherein the second layer is configured to switch between a second low resistance state and a second high resistance state, wherein the third layer is configured to switch between a third low resistance state and a third high resistance state, wherein the first low resistance state is different from the second low resistive state and different the third low resistive state, wherein the second low resistance state is different from the third low resistive state, wherein the first high resistance state is different from the second high resistive state and different the third high resistive state, and wherein the second high resistance state is different from the third high resistive state.