Abstract: A method for etching a magnetic tunneling junction (MTJ) structure is described. A stack of MTJ layers is provided on a bottom electrode. A top electrode is provided on the MTJ stack. The top electrode is patterned. Thereafter, the MTJ stack not covered by the patterned top electrode is oxidized or nitridized. Then, the MTJ stack is patterned to form a MTJ device wherein any sidewall re-deposition formed on sidewalls of the MTJ device is non-conductive and wherein some of the dielectric layer remains on horizontal surfaces of the bottom electrode.

Abstract: A plasma enhanced chemical vapor deposition (PECVD) method is disclosed for forming a SiON encapsulation layer on a magnetic tunnel junction (MTJ) sidewall that minimizes attack on the MTJ sidewall during the PECVD or subsequent processes. The PECVD method provides a higher magnetoresistive ratio for the MTJ than conventional methods after a 400° C. anneal. In one embodiment, the SiON encapsulation layer is deposited using a N2O:silane flow rate ratio of at least 1:1 but less than 15:1. A N2O plasma treatment may be performed immediately following the PECVD to ensure there is no residual silane in the SiON encapsulation layer. In another embodiment, a first (lower) SiON sub-layer has a greater Si content than a second (upper) SiON sub-layer. A second encapsulation layer is formed on the SiON encapsulation layer so that the encapsulation layers completely fill the gaps between adjacent MTJs.

Abstract: A process flow for forming magnetic tunnel junction (MTJ) nanopillars with minimal sidewall residue and minimal sidewall damage is disclosed wherein a pattern is first formed in a hard mask that is an uppermost MTJ layer. Thereafter, the hard mask sidewall is etch transferred through the remaining MTJ layers including a reference layer, free layer, and tunnel barrier between the free layer and reference layer. The etch transfer may be completed in a single RIE step that features a physical component involving inert gas ions or plasma, and a chemical component comprised of ions or plasma generated from one or more of methanol, ethanol, ammonia, and CO. In other embodiments, a chemical treatment with one of the aforementioned chemicals, and a volatilization at 50° C. to 450° C. may follow an etch transfer through the MTJ stack with an ion beam etch or plasma etch involving inert gas ions.

Abstract: A complementary metal oxide semiconductor (CMOS) device comprises a first metal line, a first metal via on the first metal line, a magnetic tunneling junction (MTJ) device on the first metal via wherein the first metal via acts as a bottom electrode for the MTJ device, a second metal via on the MTJ device, and a second metal line on the second metal via.

Abstract: A metal layer and first dielectric hard mask are deposited on a bottom electrode. These are patterned and etched to a first pattern size. The patterned metal layer is trimmed using IBE at an angle of 70-90 degrees wherein the metal layer is reduced to a second pattern size smaller than the first pattern size. A dielectric layer is deposited surrounding the patterned metal layer and polished to expose a top surface of the patterned metal layer to form a via connection to the bottom electrode. A MTJ stack is deposited on the dielectric layer and via connection. The MTJ stack is etched to a pattern size larger than the via size wherein an over etching is performed. Re-deposition material is formed on sidewalls of the dielectric layer underlying the MTJ device and not on sidewalls of a barrier layer of the MTJ device.

Abstract: A MTJ stack is deposited on a bottom electrode. A metal hard mask is deposited on the MTJ stack and a dielectric mask is deposited on the metal hard mask. A photoresist pattern is formed on the dielectric mask, having a critical dimension of more than about 65 nm. The dielectric and metal hard masks are etched wherein the photoresist pattern is removed. The dielectric and metal hard masks are trimmed to reduce their critical dimension to 10-60 nm and to reduce sidewall surface roughness. The dielectric and metal hard masks and the MTJ stack are etched wherein the dielectric mask is removed and a MTJ device is formed having a small critical dimension of 10-60 nm, and having further reduced sidewall surface roughness.

Abstract: A MTJ stack is deposited on a bottom electrode. A top electrode layer and hard mask are deposited on the MTJ stack. The top electrode layer not covered by the hard mask is etched. Thereafter, a first spacer layer is deposited over the patterned top electrode layer and the hard mask. The first spacer layer is etched away on horizontal surfaces leaving first spacers on sidewalls of the patterned top electrode layer. The free layer not covered by the hard mask and first spacers is etched. Thereafter, the steps of depositing a subsequent spacer layer over patterned previous layers, etching away the subsequent spacer layer on horizontal surfaces leaving subsequent spacers on sidewalls of the patterned previous layers, and thereafter etching a next layer not covered by the hard mask and subsequent spacers are repeated until all layers of the MTJ stack have been etched to complete the MTJ structure.

Abstract: A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A first dielectric layer is deposited on a bottom electrode and partially etched through to form a first via opening having straight sidewalls, then etched all the way through to the bottom electrode to form a second via opening having tapered sidewalls. A metal layer is deposited in the second via opening and planarized to the level of the first dielectric layer. The remaining first dielectric layer is removed leaving an electrode plug on the bottom electrode. MTJ stacks are deposited on the electrode plug and on the bottom electrode wherein the MTJ stacks are discontinuous. A second dielectric layer is deposited over the MTJ stacks and polished to expose a top surface of the MTJ stack on the electrode plug. A top electrode layer is deposited to complete the MTJ structure.

Abstract: A stack of connecting metal vias is formed on a bottom electrode by repeating steps of depositing a conductive via layer, patterning and trimming the conductive via layer to form a sub 30 nm conductive via, encapsulating the conductive via with a dielectric layer, and exposing a top surface of the conductive via. A MTJ stack is deposited on the encapsulated via stack. A top electrode layer is deposited on the MTJ stack and patterned and trimmed to form a sub 60 nm hard mask. The MTJ stack is etched using the hard mask to form an MTJ device and over etched into the encapsulation layers but not into the bottom electrode wherein metal re-deposition material is formed on sidewalls of the encapsulation layers underlying the MTJ device and not on sidewalls of a barrier layer of the MTJ device.

Abstract: A via connection is provided through a dielectric layer to a bottom electrode. A MTJ stack is deposited on the dielectric layer and via connection. A top electrode is deposited on the MTJ stack. A selective hard mask and then a dielectric hard mask are deposited on the top electrode. The dielectric and selective hard masks are patterned and etched. The dielectric and selective hard masks and the top electrode are etched wherein the dielectric hard mask is removed. The top electrode is trimmed using IBE at an angle of 70 to 90 degrees. The selective hard mask, top electrode, and MTJ stack are etched to form a MTJ device wherein over etching into the dielectric layer surrounding the via connection is performed and re-deposition material is formed on sidewalls of the dielectric layer underlying the MTJ device and not on sidewalls of a barrier layer of the MTJ device.

Abstract: A MTJ stack is deposited on a bottom electrode. A metal hard mask is deposited on the MTJ stack and a dielectric mask is deposited on the metal hard mask. A photoresist pattern is formed on the dielectric mask, having a critical dimension of more than about 65 nm. The dielectric and metal hard masks are etched wherein the photoresist pattern is removed. The dielectric and metal hard masks are trimmed to reduce their critical dimension to 10-60 nm and to reduce sidewall surface roughness. The dielectric and metal hard masks and the MTJ stack are etched wherein the dielectric mask is removed and a MTJ device is formed having a small critical dimension of 10-60 nm, and having further reduced sidewall surface roughness.

Abstract: A magnetic tunneling junction (MTJ) structure comprises a pinned layer on a bottom electrode. a barrier layer on the pinned layer, wherein a second metal re-deposition layer is on sidewalls of the barrier layer and the pinned layer, a free layer on the barrier layer wherein the free layer has a first width smaller than a second width of the pinned layer, a top electrode on the free layer having a same first width as the free layer wherein a first metal re-deposition layer is on sidewalls of the free layer and top electrode, and dielectric spacers on sidewalls of the free layer and top electrode covering the first metal re-deposition layer wherein the free layer and the top electrode together with the dielectric spacers have a same the second width as the pinned layer wherein the dielectric spacers prevent shorting between the first and second metal re-deposition layers.

Abstract: A first pattern is formed on an MTJ stack as a first array of first parallel bands. A first ion beam etching is performed on the MTJ stack using the first pattern wherein a tilt between an ion beam source and the substrate is maintained such that a horizontal component of the ion beam is parallel to the first parallel bands and the substrate is not rotated. Thereafter, a second pattern is formed on the MTJ stack as a second array of parallel bands wherein the second parallel bands are perpendicular to the first parallel bands. A second ion beam etching is performed using the second pattern wherein a tilt between an ion beam source and the substrate is maintained such that a horizontal component of the ion beam is parallel to the second parallel bands and wherein the substrate is not rotated to complete formation of the MTJ structure.

Abstract: A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A MTJ film stack is deposited on a bottom electrode on a substrate. The MTJ film stack is first ion beam etched (IBE) using a first angle and a first energy to form a MTJ device wherein conductive re-deposition forms on sidewalls of the MTJ device. Thereafter, the conductive re-deposition is oxidized. Thereafter, the MTJ device is second ion beam etched (IBE) at a second angle and a second energy to remove oxidized re-deposition.

Abstract: A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A first dielectric layer is deposited on a bottom electrode and partially etched through to form a first via opening having straight sidewalls, then etched all the way through to the bottom electrode to form a second via opening having tapered sidewalls. A metal layer is deposited in the second via opening and planarized to the level of the first dielectric layer. The remaining first dielectric layer is removed leaving an electrode plug on the bottom electrode. MTJ stacks are deposited on the electrode plug and on the bottom electrode wherein the MTJ stacks are discontinuous. A second dielectric layer is deposited over the MTJ stacks and polished to expose a top surface of the MTJ stack on the electrode plug. A top electrode layer is deposited to complete the MTJ structure.

Abstract: A conductive via layer is deposited on a bottom electrode, then patterned and trimmed to form a sub 20 nm conductive via on the bottom electrode. The conductive via is encapsulated with a first dielectric layer, which is planarized to expose a top surface of the conductive via. A MTJ stack is deposited on the encapsulated conductive via wherein the MTJ stack comprises at least a pinned layer, a barrier layer, and a free layer. A top electrode layer is deposited on the MTJ stack and patterned and trimmed to form a sub 30 nm hard mask. The MTJ stack is etched using the hard mask to form an MTJ device and over etched into the encapsulation layer but not into the bottom electrode wherein metal re-deposition material is formed on sidewalls of the encapsulation layer underlying the MTJ device and not on sidewalls of a barrier layer of the MTJ device.

Abstract: A plurality of conductive via connections are fabricated on a substrate located at positions where MTJ devices are to be fabricated, wherein a width of each of the conductive via connections is smaller than or equivalent to a width of the MTJ devices. The conductive via connections are surrounded with a dielectric layer having a height sufficient to ensure that at the end of a main MTJ etch, an etch front remains in the dielectric layer surrounding the conductive via connections. Thereafter, a MTJ film stack is deposited on the plurality of conductive via connections surrounded by the dielectric layer. The MTJ film stack is etched using an ion beam etch process (IBE), etching through the MTJ film stack and into the dielectric layer surrounding the conductive via connections to form the MTJ devices wherein by etching into the dielectric layer, re-deposition on sidewalls of the MTJ devices is insulating.

Abstract: A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A MTJ film stack is deposited on a bottom electrode on a substrate. The MTJ film stack is first ion beam etched (IBE) using a first angle and a first energy to form a MTJ device wherein conductive re-deposition forms on sidewalls of the MTJ device. Thereafter, the conductive re-deposition is oxidized. Thereafter, the MTJ device is second ion beam etched (IBE) at a second angle and a second energy to remove oxidized re-deposition.

Abstract: A first conductive layer is patterned and trimmed to form a sub 30 nm conductive via on a first bottom electrode. The conductive via is encapsulated with a first dielectric layer and planarized to expose a top surface of the conductive via. A second conductive layer is deposited over the first dielectric layer and the conductive via. The second conductive layer is patterned to form a sub 60 nm second conductive layer wherein the conductive via and second conductive layer together form a T-shaped second bottom electrode. MTJ stacks are deposited on the T-shaped second bottom electrode and on the first bottom electrode wherein the MTJ stacks are discontinuous. A second dielectric layer is deposited over the MTJ stacks and planarized to expose a top surface of the MTJ stack on the T-shaped second bottom electrode. A top electrode contacts the MTJ stack on the T-shaped second bottom electrode plug.

Abstract: A three terminal spin-orbit-torque (SOT) device is disclosed wherein a free layer (FL) with a switchable magnetization is formed on a Spin Hall Effect (SHE) layer comprising a Spin Hall Angle (SHA) material. The SHE layer has a first side contacting a first bottom electrode (BE) and an opposite side contacting a second BE where the first and second BE are separated by a dielectric spacer. A first current is applied between the two BE, and the SHE layer generates SOT on the FL thereby switching the FL magnetization to an opposite perpendicular-to-plane direction. The SHE layer is a positive or negative SHA material, and may be a topological insulator such as Bi2Sb3. A top electrode is formed on an uppermost hard mask in each SOT device. A single etch through the FL and SHE layer ensures a reliable first current pathway that is separate from a read current pathway.