公开(公告)号：US08574928B2

公开(公告)日：2013-11-05

申请号：US13443818

申请日：2012-04-10

Applicant: Kimihiro Satoh ,  Yiming Huai ,  Yuchen Zhou ,  Jing Zhang ,  Dong Ha Jung ,  Ebrahim Abedifard ,  Rajiv Yadav Ranjan ,  Parviz Keshtbod

Inventor： Kimihiro Satoh ,  Yiming Huai ,  Yuchen Zhou ,  Jing Zhang ,  Dong Ha Jung ,  Ebrahim Abedifard ,  Rajiv Yadav Ranjan ,  Parviz Keshtbod

IPC: H01L21/00

CPC classification number: H01L27/222 ,  H01L43/12

Abstract: Fabrication methods for MRAM are described wherein any re-deposited metal on the sidewalls of the memory element pillars is cleaned before the interconnection process is begun. In embodiments the pillars are first fabricated, then a dielectric material is deposited on the pillars over the re-deposited metal on the sidewalls. The dielectric material substantially covers any exposed metal and therefore reduces sources of re-deposition during subsequent etching. Etching is then performed to remove the dielectric material from the top electrode and the sidewalls of the pillars down to at least the bottom edge of the barrier. The result is that the previously re-deposited metal that could result in an electrical short on the sidewalls of the barrier is removed. Various embodiments of the invention include ways of enhancing or optimizing the process. The bitline interconnection process proceeds after the sidewalls have been etched clean as described.

Abstract translation: 描述了用于MRAM的制造方法，其中在互连过程开始之前清洁存储元件柱的侧壁上的任何重新沉积的金属。 在实施例中，首先制造柱，然后将介电材料沉积在侧壁上的再沉积金属上的柱上。 电介质材料基本上覆盖任何暴露的金属，因此在随后的蚀刻期间减少再沉积的来源。 然后进行蚀刻以将电介质材料从顶部电极和柱的侧壁向下移动到至少阻挡层的底部边缘。 结果是可能导致在屏障的侧壁上导致电短路的先前重新沉积的金属被去除。 本发明的各种实施方案包括增强或优化方法的方法。 如所描述的那样，在侧壁被蚀刻清洁之后，进行位线互连处理。

公开(公告)号：US20130148417A1

公开(公告)日：2013-06-13

申请号：US13314470

申请日：2011-12-08

Applicant: Yuchen Zhou ,  Ebrahim Abedifard ,  Yiming Huai

Inventor： Yuchen Zhou ,  Ebrahim Abedifard ,  Yiming Huai

IPC: G11C11/16

CPC classification number: G11C11/161 ,  G11C11/165

Abstract: A testing method is described that applies a sequence external magnetic fields of varying strength to MRAM cells (such as those with MTJ memory elements) in chips or wafers to selectively screen out cells with low or high thermal stability factor. The coercivity (Hc) is used as a proxy for thermal stability factor (delta). In the various embodiments the sequence, direction and strength of the external magnetic fields is used to determine the high coercivity cells that are not switched by a normal field and the low coercivity cells that are switched by a selected low field. In some embodiment the MRAM's standard internal electric current can be used to switch the cells. Standard circuit-based resistance read operations can be used to determine the response of each cell to these magnetic fields and identify the abnormal high and low coercivity cells.

Abstract translation: 描述了一种测试方法，其将具有不同强度的序列外部磁场施加到芯片或晶片中的MRAM单元（例如具有MTJ存储元件的那些），以选择性地筛选具有低或高热稳定性因子的单元。 矫顽力（Hc）用作热稳定因子（delta）的代表。 在各种实施例中，外部磁场的顺序，方向和强度用于确定不被正常场切换的高矫顽力单元以及通过选定的低场切换的低矫顽力单元。 在一些实施例中，MRAM的标准内部电流可用于切换电池。 可以使用标准的基于电路的电阻读取操作来确定每个单元对这些磁场的响应并识别异常的高和低矫顽力单元。

公开(公告)号：US20130267042A1

公开(公告)日：2013-10-10

申请号：US13443818

申请日：2012-04-10

Applicant: Kimihiro Satoh ,  Yiming Huai ,  Yuchen Zhou ,  Jing Zhang ,  Dong Ha Jung ,  Ebrahim Abedifard ,  Rajiv Yadav Ranjan ,  Parviz Keshtbod

Inventor： Kimihiro Satoh ,  Yiming Huai ,  Yuchen Zhou ,  Jing Zhang ,  Dong Ha Jung ,  Ebrahim Abedifard ,  Rajiv Yadav Ranjan ,  Parviz Keshtbod

IPC: H01L21/02

CPC classification number: H01L27/222 ,  H01L43/12

Abstract: Fabrication methods for MRAM are described wherein any re-deposited metal on the sidewalls of the memory element pillars is cleaned before the interconnection process is begun. In embodiments the pillars are first fabricated, then a dielectric material is deposited on the pillars over the re-deposited metal on the sidewalls. The dielectric material substantially covers any exposed metal and therefore reduces sources of re-deposition during subsequent etching. Etching is then performed to remove the dielectric material from the top electrode and the sidewalls of the pillars down to at least the bottom edge of the barrier. The result is that the previously re-deposited metal that could result in an electrical short on the sidewalls of the barrier is removed. Various embodiments of the invention include ways of enhancing or optimizing the process. The bitline interconnection process proceeds after the sidewalls have been etched clean as described.

Abstract translation: 描述了用于MRAM的制造方法，其中在互连过程开始之前清洁存储元件柱的侧壁上的任何重新沉积的金属。 在实施例中，首先制造柱，然后将介电材料沉积在侧壁上的再沉积金属上的柱上。 电介质材料基本上覆盖任何暴露的金属，因此在随后的蚀刻期间减少再沉积的来源。 然后进行蚀刻以将电介质材料从顶部电极和柱的侧壁向下移动到至少阻挡层的底部边缘。 结果是可能导致在屏障的侧壁上导致电短路的先前重新沉积的金属被去除。 本发明的各种实施方案包括增强或优化方法的方法。 如所描述的那样，在侧壁被蚀刻清洁之后，进行位线互连处理。

公开(公告)号：US08553452B2

公开(公告)日：2013-10-08

申请号：US13314470

申请日：2011-12-08

Applicant: Yuchen Zhou ,  Ebrahim Abedifard ,  Yiming Huai

Inventor： Yuchen Zhou ,  Ebrahim Abedifard ,  Yiming Huai

IPC: G11C11/16

CPC classification number: G11C11/161 ,  G11C11/165

Abstract: A testing method is described that applies a sequence external magnetic fields of varying strength to MRAM cells (such as those with MTJ memory elements) in chips or wafers to selectively screen out cells with low or high thermal stability factor. The coercivity (Hc) is used as a proxy for thermal stability factor (delta). In the various embodiments the sequence, direction and strength of the external magnetic fields is used to determine the high coercivity cells that are not switched by a normal field and the low coercivity cells that are switched by a selected low field. In some embodiment the MRAM's standard internal electric current can be used to switch the cells. Standard circuit-based resistance read operations can be used to determine the response of each cell to these magnetic fields and identify the abnormal high and low coercivity cells.

Abstract translation: 描述了一种测试方法，其将具有不同强度的序列外部磁场施加到芯片或晶片中的MRAM单元（例如具有MTJ存储元件的那些），以选择性地筛选具有低或高热稳定性因子的单元。 矫顽力（Hc）用作热稳定因子（delta）的代表。 在各种实施例中，外部磁场的顺序，方向和强度用于确定不被正常场切换的高矫顽力单元以及通过选定的低场切换的低矫顽力单元。 在一些实施例中，MRAM的标准内部电流可用于切换电池。 可以使用标准的基于电路的电阻读取操作来确定每个单元对这些磁场的响应并识别异常的高和低矫顽力单元。

公开(公告)号：US20190148622A9

公开(公告)日：2019-05-16

申请号：US13737897

申请日：2013-01-09

Applicant: Yiming Huai ,  Yuchen Zhou ,  Jing Zhang ,  Roger Klas Malmhall ,  Ioan Tudosa ,  Rajiv Yadav Ranjan

Inventor： Yiming Huai ,  Yuchen Zhou ,  Jing Zhang ,  Roger Klas Malmhall ,  Ioan Tudosa ,  Rajiv Yadav Ranjan

IPC: H01L43/02

Abstract: A spin-torque transfer magnetic random access memory (STTMRAM) element employed to store a state based on the magnetic orientation of a free layer, the STTMRAM element is made of a first perpendicular free layer (PFL) including a first perpendicular enhancement layer (PEL). The first PFL is formed on top of a seed layer. The STTMRAM element further includes a barrier layer formed on top of the first PFL and a second perpendicular reference layer (PRL) that has a second PEL, the second PRL is formed on top of the barrier layer. The STTMRAM element further includes a capping layer that is formed on top of the second PRL.

公开(公告)号：US09019758B2

公开(公告)日：2015-04-28

申请号：US13225338

申请日：2011-09-02

Applicant: Yiming Huai ,  Jing Zhang ,  Rajiv Yadav Ranjan ,  Yuchen Zhou ,  Roger Klas Malmhall ,  Ioan Tudosa

Inventor： Yiming Huai ,  Jing Zhang ,  Rajiv Yadav Ranjan ,  Yuchen Zhou ,  Roger Klas Malmhall ,  Ioan Tudosa

IPC: G11C11/15 ,  G11C11/16 ,  H01L43/08

CPC classification number: H01L43/10 ,  B82Y40/00 ,  G11C11/15 ,  G11C11/16 ,  G11C11/161 ,  H01F10/3286 ,  H01F10/329 ,  H01F41/302 ,  H01L27/228 ,  H01L29/66984 ,  H01L43/02 ,  H01L43/08

Abstract: A spin transfer torque magnetic random access memory (STTMRAM) element includes a composite fixed layer formed on top of a substrate and a tunnel layer formed upon the fixed layer and a composite free layer formed upon the tunnel barrier layer. The magnetization direction of each of the composite free layer and fixed layer being substantially perpendicular to the plane of the substrate. The composite layers are made of multiple repeats of a bi-layer unit which consists of a non-magnetic insulating layer and magnetic layer with thicknesses adjusted in a range that makes the magnetization having a preferred direction perpendicular to film plane.

Abstract translation: 自旋传递转矩磁随机存取存储器（STTMRAM）元件包括形成在衬底上的复合固定层和形成在固定层上的隧道层和形成在隧道势垒层上的复合自由层。 复合自由层和固定层中的每一个的磁化方向基本上垂直于衬底的平面。 复合层由双层单元的多个重复构成，该双层单元由非磁性绝缘层和厚度调节在使磁化具有与膜平面垂直的优选方向的范围内的磁性层组成。

公开(公告)号：US08830736B2

公开(公告)日：2014-09-09

申请号：US13360553

申请日：2012-01-27

Applicant: Yuchen Zhou ,  Yiming Huai

Inventor： Yuchen Zhou ,  Yiming Huai

IPC: G11C11/00 ,  G11C11/16 ,  G11C11/56

CPC classification number: G11C11/16 ,  G11C11/161 ,  G11C11/5607 ,  Y10S977/933 ,  Y10S977/935

Abstract: A method of initializing a magnetic random access memory (MRAM) element that is configured to store a state when electric current flows therethrough is disclosed. The MRAM element includes a first magnetic tunnel junction (MTJ) for storing a data bit and a second MTJ for storing a reference bit. The direction of magnetization of the FL is determinative of the data bit stored in the at least one MTJ and each MTJ further includes a magnetic reference layer (RL) having a magnetization with a direction that is perpendicular to the film plane, and a magnetic pinned layer (PL) having a magnetization with a direction that is perpendicular to the film plane. The direction of magnetization of the RL and the PL are anti-parallel relative to each other in the first MTJ. The direction of magnetization of the FL, the RL and the PL are parallel relative to each other in the second MTJ for storing reference bit.

Abstract translation: 公开了一种初始化磁性随机存取存储器（MRAM）元件的方法，该磁性随机存取存储器被配置为在电流流经时存储状态。 MRAM元件包括用于存储数据位的第一磁性隧道结（MTJ）和用于存储参考位的第二MTJ。 FL的磁化方向决定了存储在至少一个MTJ中的数据位，并且每个MTJ还包括具有与膜平面垂直的方向具有磁化的磁参考层（RL），以及磁性固定 层（PL）具有与膜平面垂直的方向的磁化。 在第一MTJ中，RL和PL的磁化方向相对于彼此是反平行的。 在第二MTJ中，FL，RL和PL的磁化方向相对于彼此平行，用于存储参考位。

公开(公告)号：US08565010B2

公开(公告)日：2013-10-22

申请号：US13099321

申请日：2011-05-02

Applicant: Yuchen Zhou ,  Yiming Huai ,  Rajiv Yadav Ranjan ,  Jing Zhang

Inventor： Yuchen Zhou ,  Yiming Huai ,  Rajiv Yadav Ranjan ,  Jing Zhang

IPC: G11C11/15

CPC classification number: G11C11/16 ,  G11C11/161 ,  H01L43/02

Abstract: A spin toque transfer magnetic random access memory (STTMRAM) element comprises a reference layer formed on a substrate, with a fixed perpendicular magnetic component. A junction layer is formed on top of the reference layer and a free layer is formed on top of the junction layer with a perpendicular magnetic orientation, at substantially its center of the free layer and switchable. A spacer layer is formed on top of the free layer and a fixed layer is formed on top of the spacer layer, the fixed layer has a fixed perpendicular magnetic component opposite to that of the reference layer. The magnetic orientation of the free layer switches relative to that of the fixed layer. The perpendicular magnetic components of the fixed layer and the reference layer substantially cancel each other and the free layer has an in-plane edge magnetization field.

Abstract translation: 自旋转矩磁性随机存取存储器（STTMRAM）元件包括形成在基板上的参考层，具有固定的垂直磁性分量。 接合层形成在参考层的顶部，并且在接合层的顶部上以自由层的大致中心位置处具有垂直磁性取向形成自由层。 间隔层形成在自由层的顶部，固定层形成在间隔层的顶部，固定层具有与基准层相反的固定的垂直磁性部件。 自由层的磁性取向相对于固定层的磁性取向。 固定层和参考层的垂直磁性分量基本相互抵消，自由层具有面内边缘磁化场。

公开(公告)号：US08492860B2

公开(公告)日：2013-07-23

申请号：US13289372

申请日：2011-11-04

Applicant: Yuchen Zhou ,  Yiming Huai ,  Jing Zhang ,  Rajiv Yadav Ranjan ,  Roger Klas Malmhall

Inventor： Yuchen Zhou ,  Yiming Huai ,  Jing Zhang ,  Rajiv Yadav Ranjan ,  Roger Klas Malmhall

IPC: H01L29/82

CPC classification number: H01L43/02 ,  G11C11/16 ,  G11C11/161 ,  G11C11/1675 ,  H01F10/3254 ,  H01F10/3272 ,  H01F10/3286 ,  H01F10/329 ,  H01L43/08 ,  H01L43/10

Abstract: A STTMRAM element includes a magnetization layer made of a first free layer and a second free layer, separated by a non-magnetic separation layer (NMSL), with the first and second free layers each having in-plane magnetizations that act on each other through anti-parallel coupling. The direction of the magnetization of the first and second free layers each is in-plane prior to the application of electrical current to the STTMRAM element and thereafter, the direction of magnetization of the second free layer becomes substantially titled out-of-plane and the direction of magnetization of the first free layer switches. Upon electrical current being discontinued to the STTMRAM element, the direction of magnetization of the second free layer remains in a direction that is substantially opposite to that of the first free layer.

Abstract translation: STTMRAM元件包括由非磁性分离层（NMSL）隔开的由第一自由层和第二自由层制成的磁化层，第一和第二自由层各自具有彼此作用的面内磁化 反平行耦合。 在向STTMRAM元件施加电流之前，第一自由层和第二自由层的磁化方向各自在同一平面内，此后，第二自由层的磁化方向基本上标称为平面外，并且 第一自由层开关的磁化方向。 当电流停止到STTMRAM元件时，第二自由层的磁化方向保持在与第一自由层基本相反的方向上。

公开(公告)号：US20130021842A1

公开(公告)日：2013-01-24

申请号：US13360553

申请日：2012-01-27

Applicant: Yuchen Zhou ,  Yiming Huai

Inventor： Yuchen Zhou ,  Yiming Huai

IPC: G11C11/16

CPC classification number: G11C11/16 ,  G11C11/161 ,  G11C11/5607 ,  Y10S977/933 ,  Y10S977/935

Abstract: A method of initializing a magnetic random access memory (MRAM) element that is configured to store a state when electric current flows therethrough is disclosed. The MRAM element includes a first magnetic tunnel junction (MTJ) for storing a data bit and a second MTJ for storing a reference bit. Each MTJ further includes a magnetic reference layer (RL) having a magnetization with a direction that is perpendicular to the film plane, and a magnetic pinned layer (PL) having a magnetization with a direction that is perpendicular to the film plane. The direction of magnetization of the RL and the PL are anti-parallel relative to each other in the first MTJ. The direction of magnetization of the FL, the RL and the PL are parallel relative to each other in the second MTJ for storing reference bit.

Abstract translation: 公开了一种初始化磁性随机存取存储器（MRAM）元件的方法，该磁性随机存取存储器被配置为在电流流经时存储状态。 MRAM元件包括用于存储数据位的第一磁性隧道结（MTJ）和用于存储参考位的第二MTJ。 每个MTJ还包括具有垂直于膜平面的方向的磁化的磁参考层（RL）和具有与膜平面垂直的方向的磁化的磁性固定层（PL）。 在第一MTJ中，RL和PL的磁化方向相对于彼此是反平行的。 在第二MTJ中，FL，RL和PL的磁化方向相对于彼此平行，用于存储参考位。