A method for fabricating semiconductor device includes the steps of first forming a magnetic tunneling junction (MTJ) stack on a substrate, in which the MTJ stack includes a pinned layer on the substrate, a barrier layer on the pinned layer, and a free layer on the barrier layer. Next, a top electrode is formed on the MTJ stack, the top electrode, the free layer, and the barrier layer are removed, a first cap layer is formed on the top electrode, the free layer, and the barrier layer, and the first cap layer and the pinned layer are removed to form a MTJ and a spacer adjacent to the MTJ.

A method for fabricating semiconductor device includes the steps of first forming a magnetic tunneling junction (MTJ) stack on a substrate, in which the MTJ stack includes a pinned layer on the substrate, a barrier layer on the pinned layer, and a free layer on the barrier layer. Next, a top electrode is formed on the MTJ stack, the top electrode, the free layer, and the barrier layer are removed, a first cap layer is formed on the top electrode, the free layer, and the barrier layer, and the first cap layer and the pinned layer are removed to form a MTJ and a spacer adjacent to the MTJ.

A method for fabricating semiconductor device includes the steps of first forming a magnetic tunneling junction (MTJ) stack on a substrate, in which the MTJ stack includes a pinned layer on the substrate, a barrier layer on the pinned layer, and a free layer on the barrier layer. Next, a top electrode is formed on the MTJ stack, the top electrode, the free layer, and the barrier layer are removed, a first cap layer is formed on the top electrode, the free layer, and the barrier layer, and the first cap layer and the pinned layer are removed to form a MTJ and a spacer adjacent to the MTJ.

Some embodiments of the present disclosure relate to a memory device. The memory device includes an active current path including a magnetic tunnel junction (MTJ); and a reference current path including a reference resistance element. The reference resistance element has a resistance that differs from a resistance of the MTJ. An asynchronous, delay-sensing element has a first input coupled to the active current path and a second input coupled to the reference current path. The asynchronous, delay-sensing element is configured to sense a timing delay between a first rising or falling edge voltage on the active current path and a second rising or falling edge voltage on the reference current path. The asynchronous, delay-sensing element is further configured to determine a data state stored in the MTJ based on the timing delay.

A method of making a physical unclonable function (PUF) having magnetic and non-magnetic particles is disclosed. Measuring both magnetic field and image view makes the PUF difficult to counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other methods are disclosed.

A multi-resistance-state spintronic device, including: a top electrode and a bottom electrode respectively connected to a read-write circuit; and a magnetic tunnel junction between two electrodes. The magnetic tunnel junction includes from top to bottom: a ferromagnetic reference layer, a barrier tunneling layer, a ferromagnetic free layer, and a spin-orbit coupling layer. Nucleation centers are provided at two ends of the ferromagnetic free layer to generate a magnetic domain wall; the spin-orbit coupling layer is connected to the bottom electrode, and when a write pulse is applied, an electron spin current is generated and drives the magnetic domain wall through a spin-orbit torque to move; a plurality of local magnetic domain wall pinning centers are provided at an interface between the spin-orbit coupling layer and the ferromagnetic free layer to enhance a strength of a DM interaction constant between interfaces.

According to one embodiment, a magnetic memory device includes a first memory portion, a first conductive portion, a first interconnection, and a controller. The first memory portion includes a first magnetic portion including a first portion and a second portion, a first magnetic layer, and a first nonmagnetic layer provided between the second portion and the first magnetic layer. The first conductive portion is electrically connected to the first portion. The first interconnection is electrically connected to the first magnetic layer. The controller is electrically connected to the first conductive portion and the first interconnection. The controller applies a first pulse having a first pulse height and a first pulse length between the first conductive portion and the first interconnection in a first write operation and applies a second pulse having a second pulse height and a second pulse length in a first shift operation.

A technique relates to a magnetic device. A stack is formed including a magnetic tunnel junction (MTJ), the MTJ including a reference magnetic layer and a free magnetic layer sandwiching a tunnel barrier layer. A protective film is formed on a bottom portion of the MTJ such that an upper portion of the MTJ is exposed. A cleaning is performed on the upper portion of the MTJ that is exposed such that any residual material is removed.

A magnetoresistive random access memory (MRAM) and associated apparatus and methods are described. The MRAM generally includes a heavy metal layer coupled to a source line, and a plurality of bit cells coupled to a word line, a plurality of bit lines, and the heavy metal layer, such that the heavy metal layer is a continuous layer coupling the bit cells to the source line, wherein each of the bit cells comprises a magnetic tunnel junction (MTJ) and a transistor, a gate of the transistor being coupled to the word line, and at least one of a source or a drain of the transistor being coupled to the MTJ or at least one of the bit lines.

A magnetoresistive random access memory (MRAM) and associated apparatus and methods are described. The MRAM generally includes a heavy metal layer coupled to a source line, and a plurality of bit cells coupled to a word line, a plurality of bit lines, and the heavy metal layer, such that the heavy metal layer is a continuous layer coupling the bit cells to the source line, wherein each of the bit cells comprises a magnetic tunnel junction (MTJ) and a transistor, a gate of the transistor being coupled to the word line, and at least one of a source or a drain of the transistor being coupled to the MTJ or at least one of the bit lines.