公开(公告)号：US11683994B2

公开(公告)日：2023-06-20

申请号：US17582190

申请日：2022-01-24

Applicant: Headway Technologies, Inc.

Inventor： Santiago Serrano Guisan ,  Luc Thomas ,  Jodi Mari Iwata ,  Guenole Jan ,  Ru-Ying Tong

IPC: H10N50/85 ,  H10N52/01 ,  H10N52/80 ,  G11C11/16 ,  H01L27/22 ,  H01L43/10 ,  H01L43/04 ,  H01L43/14 ,  H01L43/12

CPC classification number: H10N50/85 ,  G11C11/161 ,  H10N52/01 ,  H10N52/80

Abstract: A perpendicular magnetic tunnel junction is disclosed wherein a metal insertion (MIS) layer is formed within a free layer (FL), a partially oxidized Hk enhancing layer is on the FL, and a nitride capping layer having a buffer layer/nitride layer (NL) is on the Hk enhancing layer to provide an improved coercivity (Hc)/switching current (Jc) ratio for spintronic applications. Magnetoresistive ratio is maintained above 100%, resistance×area (RA) product is below 5 ohm/μm2, and thermal stability to 400° C. is realized. The FL comprises two or more sub-layers, and the MIS layer may be formed within at least one sub-layer or between sub-layers. The buffer layer is used to prevent oxygen diffusion to the NL, and nitrogen diffusion from the NL to the FL. FL thickness is from 11 Angstroms to 25 Angstroms while MIS layer thickness is preferably from 0.5 Angstroms to 4 Angstroms.

公开(公告)号：US20200152698A1

公开(公告)日：2020-05-14

申请号：US16184518

申请日：2018-11-08

Applicant: Headway Technologies, Inc.

Inventor： Huanlong Liu ,  Guenole Jan ,  Ru-Ying Tong ,  Jian Zhu ,  Yuan-Jen Lee ,  Jodi Mari Iwata ,  Sahil Patel ,  Vignesh Sundar

IPC: H01L27/22 ,  H01L43/12

Abstract: A fabrication process for an STT MTJ MRAM device includes steps of cooling the device at individual or at multiple stages in its fabrication. The cooling process, which may be equally well applied during the fabrication of other multi-layered devices, is demonstrated to produce an operational device that is more resistant to adverse thermal effects during operation that would normally cause a similar device not so fabricated to lose stored data and otherwise fail to operate properly.

公开(公告)号：US20190140168A1

公开(公告)日：2019-05-09

申请号：US16221868

申请日：2018-12-17

Applicant: Headway Technologies, Inc.

Inventor： Jian Zhu ,  Guenole Jan ,  Yuan-Jen Lee ,  Huanlong Liu ,  Ru-Ying Tong ,  Jodi Mari Iwata ,  Vignesh Sundar ,  Luc Thomas ,  Yu-Jen Wang ,  Sahil Patel

IPC: H01L43/12 ,  H01L43/10 ,  H01L43/08 ,  H01F10/16 ,  H01F10/32 ,  H01F10/30 ,  G11C11/16 ,  H01F41/30

Abstract: A seed layer stack with a uniform top surface having a peak to peak roughness of 0.5 nm is formed by sputter depositing an amorphous layer on a smoothing layer such as Mg where the latter has a resputtering rate 2 to 30× that of the amorphous layer. The uppermost seed (template) layer is NiW, NiMo, or one or more of NiCr, NiFeCr, and Hf while the bottommost seed layer is one or more of Ta, TaN, Zr, ZrN, Nb, NbN, Mo, MoN, TiN, W, WN, and Ru. Accordingly, perpendicular magnetic anisotropy in an overlying magnetic layer is substantially maintained during high temperature processing up to 400° C. and is advantageous for magnetic tunnel junctions in embedded MRAMs, spintronic devices, or in read head sensors. The amorphous seed layer is SiN, TaN, or CoFeM where M is B or another element with a content that makes CoFeM amorphous as deposited.

公开(公告)号：US20190109277A1

公开(公告)日：2019-04-11

申请号：US15728818

申请日：2017-10-10

Applicant: Headway Technologies, Inc.

Inventor： Guenole Jan ,  Jodi Mari Iwata ,  Ru-Ying Tong ,  Huanlong Liu ,  Yuan-Jen Lee ,  Jian Zhu

IPC: H01L43/08

CPC classification number: H01L43/08 ,  H01L43/10 ,  H01L43/12

Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a metal oxide (Mox) layer and a tunnel barrier layer to produce interfacial perpendicular magnetic anisotropy (PMA). The Mox layer has a non-stoichiometric oxidation state to minimize parasitic resistance, and comprises a dopant to fill vacant lattice sites thereby blocking oxygen diffusion through the Mox layer to preserve interfacial PMA and high thermal stability at process temperatures up to 400° C. Various methods of forming the doped Mox layer include deposition of the M layer in a reactive environment of O2 and dopant species in gas form, exposing a metal oxide layer to dopant species in gas form, and ion implanting the dopant. In another embodiment, where the dopant is N, a metal nitride layer is formed on a metal oxide layer, and then an anneal step drives nitrogen into vacant sites in the metal oxide lattice.

公开(公告)号：US20210175414A1

公开(公告)日：2021-06-10

申请号：US17182536

申请日：2021-02-23

Applicant: Headway Technologies, Inc.

Inventor： Santiago Serrano Guisan ,  Luc Thomas ,  Jodi Mari Iwata ,  Guenole Jan ,  Vignesh Sundar

IPC: H01L43/02 ,  H01F10/32 ,  H01L43/10 ,  H01F41/34 ,  H01L43/12

Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein a nitride diffusion barrier (NDB) has a L2/L1/NL or NL/L1/L2 configuration wherein NL is a metal nitride or metal oxynitride layer, L2 blocks oxygen diffusion from an adjoining Hk enhancing layer, and L1 prevents nitrogen diffusion from NL to the free layer (FL) thereby enhancing magnetoresistive ratio and FL thermal stability, and minimizing resistance x area product for the MTJ. NL is the uppermost layer in a bottom spin valve configuration, or is formed on a seed layer in a top spin valve configuration such that L2 and L1 are always between NL and the FL or pinned layer, respectively. In other embodiments, one or both of L1 and L2 are partially oxidized. Moreover, either L2 or L1 may be omitted when the other of L1 and L2 is partially oxidized. A spacer between the FL and L2 is optional.

公开(公告)号：US10784310B2

公开(公告)日：2020-09-22

申请号：US16184518

申请日：2018-11-08

Applicant: Headway Technologies, Inc.

Inventor： Huanlong Liu ,  Guenole Jan ,  Ru-Ying Tong ,  Jian Zhu ,  Yuan-Jen Lee ,  Jodi Mari Iwata ,  Sahil Patel ,  Vignesh Sundar

IPC: H01L27/22 ,  H01L43/12 ,  H01L43/02 ,  H01L43/08 ,  H01L43/10

Abstract: A fabrication process for an STT MTJ MRAM device includes steps of cooling the device at individual or at multiple stages in its fabrication. The cooling process, which may be equally well applied during the fabrication of other multi-layered devices, is demonstrated to produce an operational device that is more resistant to adverse thermal effects during operation that would normally cause a similar device not so fabricated to lose stored data and otherwise fail to operate properly.

公开(公告)号：US20190088866A1

公开(公告)日：2019-03-21

申请号：US16173201

申请日：2018-10-29

Applicant: Headway Technologies, Inc.

Inventor： Jian Zhu ,  Guenole Jan ,  Yuan-Jen Lee ,  Huanlong Liu ,  Ru-Ying Tong ,  Jodi Mari Iwata ,  Vignesh Sundar ,  Luc Thomas ,  Yu-Jen Wang ,  Sahil Patel

IPC: H01L43/12 ,  H01F10/30 ,  H01F41/30 ,  H01F10/32 ,  H01L43/10 ,  H01F10/16 ,  H01L43/08 ,  G11C11/16

Abstract: A seed layer stack with a uniform top surface having a peak to peak roughness of 0.5 nm is formed by sputter depositing an amorphous layer on a smoothing layer such as Mg where the latter has a resputtering rate 2 to 30× that of the amorphous layer. The seed layer stack may be repeated to give a laminate of two amorphous layers and two smoothing layers, and is advantageous for enhancing performance in magnetic tunnel junctions in embedded MRAMs, spintronic devices, or in read head sensors. A template layer such as NiCr may be formed on the uppermost smoothing layer to promote and maintain perpendicular magnetic anisotropy in an overlying magnetic layer during high temperature processing up to 400° C. The amorphous seed layer is SiN, TaN, or CoFeM where M is B or another element with a content that makes CoFeM amorphous as deposited.

公开(公告)号：US20180269387A1

公开(公告)日：2018-09-20

申请号：US15972284

申请日：2018-05-07

Applicant: Headway Technologies, Inc.

Inventor： Jodi Mari Iwata ,  Guenole Jan ,  Ru-Ying Tong ,  Po-Kang Wang

IPC: H01L43/10 ,  H01F41/32 ,  H01F10/32 ,  H01F10/16 ,  H01L43/12 ,  H01L43/08 ,  H01F10/14

CPC classification number: H01L43/10 ,  G11C11/161 ,  H01F10/142 ,  H01F10/16 ,  H01F10/32 ,  H01F10/3254 ,  H01F10/3286 ,  H01F41/32 ,  H01L43/08 ,  H01L43/12

Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to increase thermal stability. In some embodiments, a continuous or discontinuous metal (M) or MQ alloy layer within the FL reacts with scavenged oxygen to form a partially oxidized metal or alloy layer that enhances PMA and maintains acceptable RA. M is one of Mg, Al, B, Ca, Ba, Sr, Ta, Si, Mn, Ti, Zr, or Hf, and Q is a transition metal, B, C, or Al. Methods are also provided for forming composite free layers where interfacial perpendicular anisotropy is generated therein by contact of the free layer with oxidized materials.

公开(公告)号：US09966529B1

公开(公告)日：2018-05-08

申请号：US15461779

申请日：2017-03-17

Applicant: Headway Technologies, Inc.

Inventor： Jodi Mari Iwata ,  Guenole Jan ,  Ru-Ying Tong ,  Po-Kang Wang

IPC: H01L29/82 ,  H01L43/10 ,  H01L43/08 ,  H01L43/12 ,  H01F10/14 ,  H01F10/16 ,  H01F10/32 ,  H01F41/32

CPC classification number: H01L43/10 ,  G11C11/161 ,  H01F10/3254 ,  H01F10/3286 ,  H01L43/08 ,  H01L43/12

Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to increase thermal stability. In some embodiments, metal clusters are formed in the FL and are subsequently partially or fully oxidized by scavenging oxygen to generate additional FL/oxide interfaces that enhance PMA, provide an acceptable resistance x area (RA) value, and preserve the magnetoresistive ratio. In other embodiments, a continuous or discontinuous metal (M) or MQ alloy layer within the FL reacts with scavenged oxygen to form a partially oxidized metal or alloy layer that enhances PMA and maintains acceptable RA. M is one of Mg, Al, B, Ca, Ba, Sr, Ta, Si, Mn, Ti, Zr, or Hf, and Q is a transition metal, B, C, or Al.

公开(公告)号：US11264560B2

公开(公告)日：2022-03-01

申请号：US16448362

申请日：2019-06-21

Applicant: Headway Technologies, Inc.

Inventor： Jodi Mari Iwata ,  Guenole Jan ,  Santiago Serrano Guisan ,  Luc Thomas ,  Ru-Ying Tong

IPC: H01L43/10 ,  H01L43/04 ,  H01L43/14 ,  H01L43/12 ,  H01L27/22 ,  G11C11/16 ,  H01L43/02 ,  H01L43/06 ,  H01F10/32

Abstract: A perpendicular magnetic tunnel junction is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to provide thermal stability to 400° C. Insertion of an oxidation control layer (OCL) such as Mg and a magnetic moment tuning layer (MMTL) like Mo or W enables FL thickness to be reduced below 10 Angstroms while providing sufficient PMA for a switching voltage substantially less than 500 mV at a 10 ns pulse width and 1 ppm defect rate. Magnetoresistive ratio is ≥1, and resistance×area (RA) product is below 5 ohm-μm2. Embodiments are provided where MMTL and OCL materials interface with each other, or do not contact each other. Each of the MMTL and OCL materials may be deposited separately, or at least one is co-deposited with the FL.