A method for manufacturing a memory device includes forming a dielectric layer over a substrate, in which the substrate has a cell region and a logic region adjacent to the cell region. A bottom electrode, a memory layer, and a top electrode are formed in sequence over the cell region of the substrate. A first spacer is formed extending upwards from the bottom electrode. A second spacer is formed extending upwards from the dielectric layer and lining with sidewalls of the bottom electrode and the first spacer.

A memory cell with hard mask insulator and its manufacturing methods are provided. In some embodiments, a memory cell stack is formed over a substrate having a bottom electrode layer, a resistance switching dielectric layer over the bottom electrode layer, and a top electrode layer over the resistance switching dielectric layer. A first insulating layer is formed over the top electrode layer. A first metal hard masking layer is formed over the first insulating layer. Then, a series of etch is performed to pattern the first metal hard masking layer, the first insulating layer, the top electrode layer and the resistance switching dielectric layer to form a first metal hard mask, a hard mask insulator, a top electrode, and a resistance switching dielectric.

A magnetic tunnel junction (MTJ) device includes a bottom electrode, a reference layer, a tunnel barrier layer, a free layer and a top electrode. The bottom electrode and the top electrode are facing each other. The reference layer, the tunnel barrier layer and the free layer are stacked from the bottom electrode to the top electrode, wherein the free layer includes a first ferromagnetic layer, a spacer and a second ferromagnetic layer, wherein the spacer is sandwiched by the first ferromagnetic layer and the second ferromagnetic layer, wherein the spacer includes oxidized spacer sidewall parts, the first ferromagnetic layer includes first oxidized sidewall parts, and the second ferromagnetic layer includes second oxidized sidewall parts. The present invention also provides a method of manufacturing a magnetic tunnel junction (MTJ) device.

An etching method includes: preparing a workpiece including a metal multilayer film having a magnetic tunnel junction and a mask formed by an inorganic material on the metal multilayer film; and etching the metal multilayer film by plasma of a mixed gas of ethylene gas and oxygen gas using the mask.

A semiconductor device includes: a substrate comprising a magnetic tunneling junction (MTJ) region and a logic region, a MTJ on the MTJ region, a top electrode on the MTJ, a connecting structure on the top electrode, and a first metal interconnection on the logic region. Preferably, the first metal interconnection includes a via conductor on the substrate and a trench conductor, in which a bottom surface of the trench conductor is lower than a bottom surface of the connecting structure.

Aspects of the present disclosure are directed to magnetic tunnel junction (MTJ) structures comprising multiple MTJ bits connected in series. For example, a magnetic tunnel junction (MTJ) stack according to the present disclosure may include at least a first MTJ bit and a second MTJ bit stacked above the first MTJ bit, and a resistance state of the MTJ stack may be read by passing a single read current through both the first MTJ bit and the second MTJ bit.

A true random number generator (TRNG) device having a magnetic tunnel junction (MTJ) structure coupled to a domain wall wire. The MTJ structure is formed of a free layer (FL) and a reference layer (RL) that sandwiches a tunnel barrier layer. The free layer has anisotropy energy sufficiently low to provide stochastic fluctuation in the orientation of the magnetic state of the free layer via thermal energy. The domain wall wire is coupled to the MTJ structure. The domain wall wire has a domain wall. Movement of the domain wall tunes a probability distribution of the fluctuation in the orientation of the magnetic state of the free layer. The domain wall can be moved by application of a suitable current through the wire to tune the probability distribution of 1's and 0's generated by a readout circuit of the TRNG device.

A method for manufacturing a semiconductor device includes forming a plurality of memory elements on a first interconnect level, and forming an etch stop layer on the plurality of memory elements. A dielectric layer is formed on the etch stop layer, and a portion of the dielectric over the plurality of memory elements is removed to expose a portion of the etch stop layer. The method further includes removing the exposed portion of the etch stop layer. The removing of the portion of the dielectric layer and of the exposed portion of the etch stop layer forms a trench. A metallization layer is formed in the trench on the plurality of memory elements, wherein the metallization layer is part of a second interconnect level.

A method of forming a tunnel layer of a magnetoresistive random-access memory (MRAM) structure includes forming a first magnesium oxide (MgO) layer by sputtering an MgO target using radio frequency (RF) power, exposing the first MgO layer to oxygen for approximately 5 seconds to approximately 20 seconds at a flow rate of approximately 10 sccm to approximately 15 sccm, and forming a second MgO layer on the first MgO layer by sputtering the MgO target using RF power. The method may be performed after periodic maintenance of a process chamber to increase the tunnel magnetoresistance (TMR) of the tunnel layer.

In some embodiments, the present disclosure relates to an integrated chip (IC), including a bottom electrode overlying an interconnect structure disposed within a lower inter-level dielectric (ILD) layer, a top electrode over the bottom electrode, a data storage structure between the top electrode from the bottom electrode, a conductive barrier layer directly overlying the interconnect structure, and a bottom electrode via (BEVA) vertically separating and contacting a bottom surface of the bottom electrode and a top surface of the conductive barrier layer. A maximum width of the BEVA is less than a width of the data storage structure.