公开(公告)号：US20130043471A1

公开(公告)日：2013-02-21

申请号：US13136929

申请日：2011-08-15

申请人： Wei Cao ,  Witold Kula ,  Chyu-Jiuh Torng

发明人： Wei Cao ,  Witold Kula ,  Chyu-Jiuh Torng

IPC分类号： H01L29/04 ,  H01L21/36

CPC分类号： H01L43/10 ,  B82Y40/00 ,  H01F10/3272 ,  H01F10/3295 ,  H01F41/307 ,  H01L43/12

摘要： Reading margin is improved in a MTJ designed for MRAM applications by employing a pinned layer with an AP2/Ru/AP1 configuration wherein the AP1 layer is a CoFeB/CoFe composite and by forming a MgO tunnel barrier adjacent to the CoFe AP1 layer by a sequence that involves depositing and oxidizing a first Mg layer with a radical oxidation (ROX) process, depositing and oxidizing a second Mg layer with a ROX method, and depositing a third Mg layer on the oxidized second Mg layer. The third Mg layer becomes oxidized during a subsequent anneal. MTJ performance may be further improved by selecting a composite free layer having a Fe/NiFeHf or CoFe/Fe/NiFeHf configuration where the NiFeHf layer adjoins a capping layer in a bottom spin valve configuration. As a result, read margin is optimized simultaneously with improved MR ratio, a reduction in bit line switching current, and a lower number of shorted bits.

公开(公告)号：US20120181537A1

公开(公告)日：2012-07-19

申请号：US12930877

申请日：2011-01-19

申请人： Wei Cao ,  Cheng T. Horng ,  Witold Kula ,  Chyu Jiuh Torng

发明人： Wei Cao ,  Cheng T. Horng ,  Witold Kula ,  Chyu Jiuh Torng

IPC分类号： H01L29/82 ,  H01L21/36 ,  H01L29/04

CPC分类号： H01L43/10 ,  G11C11/161 ,  H01L27/222 ,  H01L43/00 ,  H01L43/02 ,  H01L43/08

摘要： A MTJ in an MRAM array is disclosed with a composite free layer having a lower crystalline layer contacting a tunnel barrier and an upper amorphous NiFeX layer for improved bit switching performance. The crystalline layer is Fe, Ni, or FeB with a thickness of at least 6 Angstroms which affords a high magnetoresistive ratio. The X element in the NiFeX layer is Mg, Hf, Zr, Nb, or Ta with a content of 5 to 30 atomic %. NiFeX thickness is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. In an alternative embodiment, the crystalline layer may be a Fe/NiFe bilayer. Optionally, the amorphous layer may have a NiFeM1/NiFeM2 configuration where M1 and M2 are Mg, Hf, Zr, Nb, or Ta, and M1 is unequal to M2. Annealing at 300° C. to 360° C. provides a high magnetoresistive ratio of about 150%.

摘要翻译： 公开了具有接触隧道势垒的较低结晶层和上部非晶NiFeX层的复合自由层的MRAM阵列中的MTJ，用于改善位切换性能。 结晶层是厚度至少为6埃的Fe，Ni或FeB，其具有高的磁阻比。 NiFeX层中的X元素为含有5〜30原子％的Mg，Hf，Zr，Nb或Ta。 NiFeX厚度优选在20至40埃之间，以显着减少位线切换电流和短路位数。 在替代实施例中，结晶层可以是Fe / NiFe双层。 可选地，非晶层可以具有其中M1和M2是Mg，Hf，Zr，Nb或Ta的NiFeM1 / NiFeM2构型，M1不等于M2。 在300℃至360℃退火，提供约150％的高磁阻比。

公开(公告)号：US08786036B2

公开(公告)日：2014-07-22

申请号：US12930877

申请日：2011-01-19

申请人： Wei Cao ,  Cheng T. Horng ,  Witold Kula ,  Chyu Jiuh Torng

发明人： Wei Cao ,  Cheng T. Horng ,  Witold Kula ,  Chyu Jiuh Torng

IPC分类号： H01L43/10 ,  H01L27/22

CPC分类号： H01L43/10 ,  G11C11/161 ,  H01L27/222 ,  H01L43/00 ,  H01L43/02 ,  H01L43/08

摘要： A MTJ in an MRAM array is disclosed with a composite free layer having a lower crystalline layer contacting a tunnel barrier and an upper amorphous NiFeX layer for improved bit switching performance. The crystalline layer is Fe, Ni, or FEB with a thickness of at least 6 Angstroms which affords a high magnetoresistive ratio. The X element in the NiFeX layer is Mg, Hf, Zr, Nb, or Ta with a content of 5 to 30 atomic % NiFeX thickness is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. In an alternative embodiments, the crystalline layer may be a Fe/NiFe bilayer. Optionally, the amorphous layer may have a NiFeM1/NiFeM2 configuration where M1 and M2 are Mg, Hf, Zr, Nb, or Ta, and M1 is unequal to M2. Annealing at 300° C. to 360° C. provides a high magnetoresistive ratio of about 150%.

摘要翻译： 公开了具有接触隧道势垒的较低结晶层和上部非晶NiFeX层的复合自由层的MRAM阵列中的MTJ，用于改善位切换性能。 结晶层是厚度至少为6埃的Fe，Ni或FEB，其具有高的磁阻比。 NiFeX层中的X元素为含有5〜30原子％NiFeX厚度的Mg，Hf，Zr，Nb或Ta优选为20〜40埃，以显着降低位线切换电流和短路位数。 在替代实施例中，结晶层可以是Fe / NiFe双层。 可选地，非晶层可以具有其中M1和M2是Mg，Hf，Zr，Nb或Ta的NiFeM1 / NiFeM2构型，M1不等于M2。 在300℃至360℃退火，提供约150％的高磁阻比。

公开(公告)号：US08492169B2

公开(公告)日：2013-07-23

申请号：US13136929

申请日：2011-08-15

申请人： Wei Cao ,  Witold Kula ,  Chyu-Jiuh Torng

发明人： Wei Cao ,  Witold Kula ,  Chyu-Jiuh Torng

IPC分类号： H01L29/82 ,  H01L29/88 ,  G11C11/02

CPC分类号： H01L43/10 ,  B82Y40/00 ,  H01F10/3272 ,  H01F10/3295 ,  H01F41/307 ,  H01L43/12

摘要： Reading margin is improved in a MTJ designed for MRAM applications by employing a pinned layer with an AP2/Ru/AP1 configuration wherein the AP1 layer is a CoFeB/CoFe composite and by forming a MgO tunnel barrier adjacent to the CoFe AP1 layer by a sequence that involves depositing and oxidizing a first Mg layer with a radical oxidation (ROX) process, depositing and oxidizing a second Mg layer with a ROX method, and depositing a third Mg layer on the oxidized second Mg layer. The third Mg layer becomes oxidized during a subsequent anneal. MTJ performance may be further improved by selecting a composite free layer having a Fe/NiFeHf or CoFe/Fe/NiFeHf configuration where the NiFeHf layer adjoins a capping layer in a bottom spin valve configuration. As a result, read margin is optimized simultaneously with improved MR ratio, a reduction in bit line switching current, and a lower number of shorted bits.

摘要翻译： 通过采用具有AP2 / Ru / AP1配置的钉扎层，其中AP1层是CoFeB / CoFe复合材料并且通过顺序形成与CoFe AP1层相邻的MgO隧道势垒，为MRAM应用设计的MTJ中的读取余量得到改善 其包括用自由基氧化（ROX）工艺沉积和氧化第一Mg层，用ROX法沉积和氧化第二Mg层，以及在氧化的第二Mg层上沉积第三Mg层。 在随后的退火中，第三Mg层变成氧化的。 通过选择具有Fe / NiFeHf或CoFe / Fe / NiFeHf构型的复合自由层，其中NiFeHf层与底部自旋阀结构中的覆盖层邻接，可以进一步改善MTJ性能。 结果，读取余量同时优化了MR比，降低了位线切换电流，并且更少的短路位数。

公开(公告)号：US08372661B2

公开(公告)日：2013-02-12

申请号：US11981127

申请日：2007-10-31

申请人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

发明人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

IPC分类号： H01L21/00

CPC分类号： H01L43/10 ,  B82Y10/00 ,  H01L27/228 ,  H01L43/08 ,  H01L43/12

摘要： A STT-RAM MTJ that minimizes spin-transfer magnetization switching current (Jc) is disclosed. The MTJ has a MgO tunnel barrier layer formed with a natural oxidation process to achieve a low RA (10 ohm-um2) and a Fe or Fe/CoFeB/Fe free layer which provides a lower intrinsic damping constant than a CoFeB free layer. A Fe, FeB, or Fe/CoFeB/Fe free layer when formed with a MgO tunnel barrier (radical oxidation process) and a CoFeB AP1 pinned layer in a MRAM MTJ stack annealed at 360° C. provides a high dR/R (TMR)>100% and a substantial improvement in read margin with a TMR/Rp_cov=20. High speed measurement of 100 nm×200 nm oval STT-RAM MTJs has shown a Jc0 for switching a Fe free layer is one half that for switching an amorphous CO40Fe40B20 free layer. A Fe/CoFeB/Fe free layer configuration allows the Hc value to be increased for STT-RAM applications.

摘要翻译： 公开了使自旋转移磁化开关电流（Jc）最小化的STT-RAM MTJ。 MTJ具有形成有自然氧化工艺的MgO隧道阻挡层，以实现低的RA（10欧姆 - um2）和不含CoFeB自由层的较低的固有阻尼常数的Fe或Fe / CoFeB / Fe自由层。 当在360℃退火的MRAM MTJ堆叠中形成具有MgO隧道势垒（自由基氧化法）和CoFeB AP1钉扎层的Fe，FeB或Fe / CoFeB / Fe自由层时，提供高dR / R（TMR ）> 100％，TMR / Rp_cov = 20时读取余量大幅度提高。 100 nm×200 nm椭圆STT-RAM MTJ的高速测量显示，用于切换无Fe层的Jc0是用于切换无定形CO40Fe40B20自由层的一半。 Fe / CoFeB / Fe自由层配置允许为STT-RAM应用增加Hc值。

公开(公告)号：US07936027B2

公开(公告)日：2011-05-03

申请号：US12006889

申请日：2008-01-07

申请人： Rongfu Xiao ,  Chyu-Jiuh Torng ,  Tom Zhong ,  Witold Kula

发明人： Rongfu Xiao ,  Chyu-Jiuh Torng ,  Tom Zhong ,  Witold Kula

IPC分类号： G11C11/02

CPC分类号： H01L43/12 ,  H01L43/08

摘要： An MTJ cell without footings and free from electrical short-circuits across a tunneling barrier layer is formed by using a Ta hard mask layer and a combination of etches. A first etch patterns the Ta hard mask, while a second etch uses O2 applied in a single high power process at two successive different power levels. A first power level of between approximately 200 W and 500 W removes BARC, photoresist and Ta residue from the first etch, the second power level, between approximately 400 W and 600 W continues an etch of the stack layers and forms a protective oxide around the etched sides of the stack. Finally, an etch using a carbon, hydrogen and oxygen gas completes the etch while the oxide layer protects the cell from short-circuits across the lateral edges of the barrier layer.

摘要翻译： 通过使用Ta硬掩模层和蚀刻的组合，形成没有底脚并且穿过隧道势垒层的电短路的MTJ电池。 第一蚀刻图案Ta硬掩模，而第二蚀刻使用在两个连续的不同功率水平下在单个高功率过程中施加的O2。 在大约200W至500W之间的第一功率电平从第一蚀刻去除BARC，光致抗蚀剂和Ta残留物，第二功率电平在大约400W至600W之间，继续蚀刻叠层，并在其周围形成保护氧化物 蚀刻边的堆叠。 最后，使用碳，氢和氧气的蚀刻完成了蚀刻，而氧化物层保护电池免受横跨阻挡层的侧边缘的短路。

公开(公告)号：US20100258889A1

公开(公告)日：2010-10-14

申请号：US12803191

申请日：2010-06-21

申请人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

发明人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

IPC分类号： H01L29/82

CPC分类号： H01L43/08 ,  B82Y25/00 ,  B82Y40/00 ,  G11C11/161 ,  H01F10/3272 ,  H01F10/329 ,  H01F10/3295 ,  H01F41/307 ,  H01L43/10 ,  H01L43/12

摘要： An STT-MTJ MRAM cell utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The cell includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a composite tri-layer free layer that comprises an amorphous layer of Co60Fe20B20 of approximately 20 angstroms thickness formed between two crystalline layers of Fe of 3 and 6 angstroms thickness respectively. The free layer is characterized by a low Gilbert damping factor and by very strong polarizing action on conduction electrons. The resulting cell has a low critical current, a high dR/R and a plurality of such cells will exhibit a low variation of both resistance and pinned layer magnetization angular dispersion.

摘要翻译： STT-MTJ MRAM单元利用自旋角动量的传递作为改变自由层的磁矩方向的机构。 电池包括形成在被钉扎层的Ar离子等离子体平滑表面上的IrMn钉扎层，SyAP钉扎层，自然氧化的结晶的MgO隧道势垒层，在一个实施例中，复合三层自由层 其包括分别在3和6埃厚度的Fe的两个结晶层之间形成的约20埃厚度的Co60Fe20B20的非晶层。 自由层的特征在于低吉尔伯特阻尼因子和对传导电子的非常强的偏振作用。 所得到的电池具有低临界电流，高dR / R，并且多个这样的电池将呈现电阻和钉扎层磁化角分散的低变化。

公开(公告)号：US20080088986A1

公开(公告)日：2008-04-17

申请号：US11582244

申请日：2006-10-17

申请人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

发明人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

IPC分类号： G11B5/33 ,  G11B5/127

CPC分类号： H01F10/3254 ,  B82Y25/00 ,  G11B5/3163 ,  G11B5/3906 ,  G11C11/161 ,  H01F10/3281 ,  H01F10/3295 ,  H01F41/325 ,  H01L43/08 ,  H01L43/10 ,  H01L43/12 ,  Y10T29/49041 ,  Y10T29/49043 ,  Y10T29/49044 ,  Y10T29/49046 ,  Y10T29/49048 ,  Y10T29/49052

摘要： A high performance MTJ, and a process for manufacturing it, are described. A capping layer of NiFeHf is used to getter oxygen out of the free layer, thereby increasing the sharpness of the free layer-tunneling layer interface. The free layer comprises two NiFe layers whose magnetostriction constants are of opposite sign, thereby largely canceling one another.

摘要翻译： 描述了高性能MTJ及其制造方法。 使用NiFeHf的覆盖层将氧气从自由层中吸出，从而增加了自由层 - 隧道层界面的清晰度。 自由层包含两个NiFe层，它们的磁致伸缩常数是相反的，从而很大程度地相互抵消。

公开(公告)号：US08176622B2

公开(公告)日：2012-05-15

申请号：US12657775

申请日：2010-01-27

申请人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

发明人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

IPC分类号： G11B5/127 ,  H04R31/00

CPC分类号： H01F10/3254 ,  B82Y25/00 ,  G11B5/3163 ,  G11B5/3906 ,  G11C11/161 ,  H01F10/3281 ,  H01F10/3295 ,  H01F41/325 ,  H01L43/08 ,  H01L43/10 ,  H01L43/12 ,  Y10T29/49041 ,  Y10T29/49043 ,  Y10T29/49044 ,  Y10T29/49046 ,  Y10T29/49048 ,  Y10T29/49052

摘要： A process for manufacturing a high performance MTJ it is described: A first cap layer of NiFeHf is deposited on the free layer, followed by a second cap layer of Ru on Ta. The device is then heated so that oxygen trapped in the free layer diffuses into the NiFeHf layer, thereby sharpening the interface between the tunnel barrier layer and the free layer.

摘要翻译： 描述了一种用于制造高性能MTJ的方法：将NiFeHf的第一覆盖层沉积在自由层上，随后是Ta上的Ru的第二盖层。 然后加热该装置，使得在自由层中捕获的氧气扩散到NiFeHf层中，从而锐化隧道势垒层和自由层之间的界面。

公开(公告)号：US08058698B2

公开(公告)日：2011-11-15

申请号：US12803189

申请日：2010-06-21

申请人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

发明人： Cheng T. Horng ,  Ru-Ying Tong ,  Chyu-Jiuh Torng ,  Witold Kula

IPC分类号： H01L29/82 ,  G11C11/00

CPC分类号： H01L43/08 ,  B82Y25/00 ,  B82Y40/00 ,  G11C11/161 ,  H01F10/3272 ,  H01F10/329 ,  H01F10/3295 ,  H01F41/307 ,  H01L43/10 ,  H01L43/12

摘要： An STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that is an amorphous layer of Co60Fe20B20 of approximately 20 angstroms thickness formed between two crystalline layers of Fe of 3 and 6 angstroms thickness respectively. The free layer has a low Gilbert damping factor and a very strong polarizing action on conduction electrons. The resulting cell has a low critical current, a high dR/R and a plurality of such cells will exhibit a low variation of both resistance and pinned layer magnetization angular dispersion.

摘要翻译： 利用转移自旋角动量作为改变自由层的磁矩方向的机构的STT-MTJ MRAM单元。 该器件包括形成在钉扎层的Ar离子等离子体平滑表面上的IrMn钉扎层，SyAP钉扎层，自然氧化的结晶的MgO隧道势垒层，在一个实施例中，是非晶形的自由层 分别在3和6埃厚度的Fe的两个结晶层之间形成大约20埃厚度的Co60Fe20B20层。 自由层具有低的吉尔伯特衰减因子和对传导电子的非常强的偏振作用。 所得到的电池具有低临界电流，高dR / R，并且多个这样的电池将呈现电阻和钉扎层磁化角分散的低变化。