WO2022160226A1 - 一种存储阵列、存储器、制备方法及写入方法 - Google Patents
一种存储阵列、存储器、制备方法及写入方法 Download PDFInfo
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Definitions
- the present invention relates to the field of semiconductors, and more particularly, to a storage array, a memory, a preparation method and a writing method.
- Magnetic random access memory has attracted great attention in academic and industrial fields due to its advantages of non-volatility, radiation resistance, and low power consumption.
- Magnetic tunnel junction is the basic storage unit of magnetic random access memory (MRAM).
- the core part of the MTJ consists of two magnetic metal layers and a barrier layer sandwiched between the two magnetic metal layers.
- One of the magnetic metal layers called the reference layer, has a fixed magnetization.
- Another magnetic metal layer is called the free layer, and its magnetization has two stable orientations.
- the MTJ can exhibit two states, that is, the magnetization directions of the two magnetic layers are parallel to each other (parallel, P) or antiparallel (AP), so that the MTJ appears in a low-resistance state or a high-resistance state.
- This effect is called tunneling.
- Magnetoresistance effect tunnelnel magnetoresistance, TMR.
- TMR tunneling magnetoresistance
- STT-MRAM spin transfer torque magnetoresistive RAM
- the write operation of STT-MRAM uses the spin transfer torque effect to flip the magnetization direction of the free magnetic layer; the read operation is performed by the tunneling magnetoresistance effect of the magnetic tunnel junction.
- Current STT-MRAM write current directions are reversed when writing a "0" and writing a "1".
- the MTJ flips from parallel to anti-parallel, which is inconsistent with the current magnitude when anti-parallel flips to parallel, that is, the efficiency of STT flip is asymmetric.
- STT-MRAM is also limited by the inherent inversion time delay of the STT effect, which greatly affects the writing speed of STT-MRAM.
- SOT-MRAM spin orbit torque magnetic random access memory
- the basic unit structure of SOT-MRAM is MTJ, heavy metal layer or ferromagnetic layer and two access transistors.
- the MTJ is a free layer/barrier layer/reference layer/pinning layer from bottom to top.
- Below the free layer of the MTJ is a heavy metal or antiferromagnetic layer. The current flowing through the heavy metal or antiferromagnetic layer can induce a torque to flip the MTJ.
- the magnetization direction of the free layer enables magnetic writing.
- SOT effect writing solves the problem of writing speed, but since the existing SOT-MRAM basic cell structure includes two access transistors, namely, a writing transistor and a reading transistor, and the writing transistor is the same as the The read transistor width is the same, making it difficult to increase the integration density. At the same time, the problem of source-level degradation of transistors still exists.
- the present invention provides a storage array, a memory, a preparation method and a writing method. Some embodiments relate to a storage array including a magnetoresistive random access memory and a fabrication method thereof.
- the storage array includes: a plurality of storage cells arranged in an array.
- each memory cell includes: a writing transistor, the first end of which is coupled with the top electrode wiring; an MTJ magnetic tunnel junction, whose end close to the reference layer is coupled with the second end of the writing transistor; One side surface of the conductor layer is coupled with one end face of all the MTJ magnetic tunnel junctions close to the free layer; wherein, the two ends of the conductor layer are respectively coupled to high-level wiring and low-level wiring, and the present invention simultaneously STT and SOT effects are applied to magnetic tunnel junction flipping, which improves write speed and device reliability relative to STT-MRAM, reduces circuit static power consumption compared to the SOT-MRAM model, and reduces The number of transistors increases the device storage density.
- a first aspect of the present invention provides a storage array of a magnetoresistive random access device, including: a plurality of storage cells and conductor layers arranged in an array; each storage cell includes:
- a writing transistor the first end of which is coupled to the top electrode wiring
- an MTJ magnetic tunnel junction one end of which is close to the reference layer is coupled to the second end of the writing transistor;
- One side surface of the conductor layer is coupled to one end face of all the MTJ magnetic tunnel junctions close to the free layer; wherein, two ends of the conductor layer are respectively coupled to high-level wiring and low-level wiring.
- all write transistors in the memory array are integrated in a first wafer, and all MTJ magnetic tunnel junctions in the memory array are integrated in a second wafer, the first wafer and the second wafer are connected together by bonding.
- switching elements are provided on both the high-level wiring and the low-level wiring.
- the conductor layer is in the shape of an elongated strip, the top area of which is larger than the bottom area of all magnetic tunnel junctions, and the bottom surface shape of the magnetic tunnel junction is completely embedded in the top surface shape of the conductor layer.
- the embodiment of the second aspect of the present invention provides a memory, including: a plurality of storage array groups, each storage array group includes a pair of storage arrays, a high-level wiring and a low-level wiring;
- the memory array includes a plurality of memory cells and conductor layers arranged in an array
- Each storage unit includes:
- a writing transistor the first end of which is coupled to the top electrode wiring
- an MTJ magnetic tunnel junction one end of which is close to the reference layer is coupled to the second end of the writing transistor;
- One side surface of the conductor layer is coupled to one end face of all the MTJ magnetic tunnel junctions close to the free layer; wherein, two ends of the conductor layer are respectively coupled to high-level wiring and low-level wiring.
- the high-level wiring is located between a pair of memory arrays in each memory array group, and ends of the conductor layers of the pair of memory arrays that are close to each other are coupled to the high-level wiring , and the opposite ends of the conductor layers of the pair of memory arrays are respectively coupled to a low-level wire.
- the low-level wiring is located between a pair of memory arrays in each memory array group, and ends of the conductor layers of the pair of memory arrays that are close to each other are coupled to the low-level wiring and the ends of the conductor layers of the pair of memory arrays facing away from each other are respectively coupled to a high-level wire.
- a third aspect of the present invention provides a method for preparing a storage array, including:
- Two ends of the conductor layer are respectively coupled to the high-level wiring and the low-level wiring.
- forming a plurality of write transistors includes:
- the forming a plurality of MTJ magnetic tunnel junctions corresponding to the writing transistors one-to-one includes:
- Embodiments of the fourth aspect of the present invention provide a data writing method using the storage array as described in the embodiments of the first aspect, including:
- the high-level wiring and the low-level wiring are turned on, so that all MTJ magnetic tunnel junctions in the storage array are set to a first resistance state; wherein, the first resistance state corresponds to a first value, which is the same as the first resistance state.
- the second resistance state opposite to the resistance state corresponds to the second value;
- the corresponding position of the MTJ magnetic tunnel junction is selected
- the write transistor coupled to the MTJ magnetic tunnel junction is turned on, and one of the high-level wiring and the low-level wiring is turned on, so that the MTJ magnetic tunnel junction at the corresponding position is switched to the second resistance state.
- the present invention provides a storage array, a memory, a preparation method and a writing method. Some embodiments relate to a storage array including a magnetoresistive random access memory and a fabrication method thereof.
- the storage array includes: a plurality of storage cells arranged in an array.
- each memory cell includes: a writing transistor, the first end of which is coupled with the top electrode wiring; an MTJ magnetic tunnel junction, whose end close to the reference layer is coupled with the second end of the writing transistor; One side surface of the conductor layer is coupled with one end face of all the MTJ magnetic tunnel junctions close to the free layer; wherein, the two ends of the conductor layer are respectively coupled to high-level wiring and low-level wiring, and the present invention simultaneously STT and SOT effects are applied to magnetic tunnel junction flipping, which improves write speed and device reliability relative to STT-MRAM, reduces circuit static power consumption compared to the SOT-MRAM model, and reduces The number of transistors increases the device storage density.
- FIG. 1 is one of the structural schematic diagrams of a three-dimensional high-density NAND-like magnetic memory in an embodiment of the present invention
- FIG. 2 is one of schematic diagrams of manufacturing a magnetic memory in an embodiment of the present invention
- FIG. 3 is a second schematic structural diagram of a three-dimensional high-density NAND-like magnetic memory according to an embodiment of the present invention.
- FIG. 4 is the second schematic diagram of the manufacture of a magnetic memory according to an embodiment of the present invention.
- FIG. 5 is a third schematic structural diagram of a three-dimensional high-density NAND-like magnetic memory according to an embodiment of the present invention.
- FIG. 6 is a third schematic diagram of the manufacture of a magnetic memory according to an embodiment of the present invention.
- FIG. 7 is a flowchart of a method for preparing a storage array in an embodiment of the present invention.
- FIG. 8 is a flowchart of a method for writing data to a storage array according to an embodiment of the present invention.
- first part over or on the second part may include embodiments in which the first part and the second part are formed in direct contact, and may also include additionally forming between the first part and the second part. parts so that the first part and the second part may not be in direct contact.
- present invention may repeat reference numerals and/or characters in various embodiments. This repetition is for the purpose of simplicity and clarity, and does not in itself indicate a relationship between the various embodiments and/or configurations discussed.
- spatially relative terms such as “below”, “below”, “lower”, “above”, “upper” and the like may be used herein to describe the The relationship of one element or part to another (or other) elements or parts.
- spatially relative terms are intended to encompass different orientations of the device in use or operation.
- the existing SOT-MRAM has a basic structure of MTJ, a heavy metal layer or a ferromagnetic layer and two access transistors, namely a write transistor and a read transistor.
- the write current is much larger than the read current.
- the width of the write transistor and the read transistor is the same, making it difficult to improve the integration level.
- the problem of transistor source-level degradation still exists.
- the first aspect of the present invention provides a storage array of a magnetoresistive random access device, including: a plurality of storage cells and conductor layers arranged in an array; each storage cell includes: a writing transistor, Its first end is coupled with the top electrode wiring; the MTJ magnetic tunnel junction, its end close to the reference layer is coupled with the second end of the writing transistor; one side surface of the conductor layer is connected to all the MTJ magnetic tunnels The junction is coupled near one end of the free layer; wherein, the two ends of the conductor layer are respectively coupled to the high-level wiring and the low-level wiring.
- the memory array in the embodiment of the present invention applies both STT and SOT effects to magnetic tunnel junction flipping.
- the magnetic memory has improved writing speed and device reliability.
- the magnetic memory has improved The memory reduces the static power consumption of the circuit, reduces the number of transistors, and increases the storage density of the device.
- the "coupling" in the embodiments of the present invention may include an embodiment in which the first component and the second component are in direct contact, and may also include additional components that may be formed between the first component and the second component, Thus, an embodiment in which the first part and the second part may not be in direct contact.
- the write transistors include, but are not limited to, conventional transistors, tunneling field effect transistors, FinFETs, and vertical gate-all-around transistors.
- the shape of the magnetic tunnel junction includes, but is not limited to, a square, a rectangle, a circle or an ellipse.
- the semiconductor process processing used in the embodiments of the present invention mainly includes: deep ultraviolet lithography (DUV), exposure technologies such as electron beam direct writing (EBL); inductively coupled plasma etching (ICP), capacitively coupled plasma etching (CCP) , Ion beam etching (IBE) and other etching technologies, plasma enhanced chemical vapor deposition (PECVD), chemical vapor deposition (CVD) and other dielectric deposition technologies; magnetron sputtering (Magnetron sputtering) and other metal deposition technologies.
- DUV deep ultraviolet lithography
- EBL electron beam direct writing
- ICP inductively coupled plasma etching
- CCP capacitively coupled plasma etching
- IBE Ion beam etching
- PECVD plasma enhanced chemical vapor deposition
- CVD chemical vapor deposition
- Magnetron sputtering magnetron sputtering
- the NAND magnetic memory is a better storage solution than a hard disk drive.
- the magnetic memory includes a storage part and a control part.
- the part includes a magnetic tunnel junction MTJ and a conductor layer;
- the control part includes a high-level wiring Vdd, a low-level wiring GND and a write transistor.
- a plurality of magnetic tunnel junctions are fabricated on the conductor layer.
- the main structures of the magnetic tunnel junctions from bottom to top are the first ferromagnetic metal layer, the first oxide layer, the second ferromagnetic metal layer, and the first synthetic antiferromagnetic metal layer.
- the layer, the Xth top electrode, and the Xth magnetic tunnel junction are interconnected with the source level or the drain level of the Xth write transistor through the Xth top electrode, and each magnetic tunnel junction and the write transistor together represent a memory cell.
- the conductor layer is an antiferromagnetic layer strip film or a heavy metal layer strip film, including but not limited to platinum, tantalum, tungsten, iridium manganese, platinum manganese and the like.
- the thicknesses of the first ferromagnetic metal layer and the second ferromagnetic metal layer are the same or different, respectively, ranging from 0 to 3 nm, and the two magnetic layers are both composed of magnetic materials, including but not limited to elemental ferromagnetic materials, such as iron , cobalt, nickel, etc; Structures include, but are not limited to, monolayer films, bilayer films, and multilayer films.
- all write transistors in the memory array are integrated in a first wafer, and all MTJ magnetic tunnel junctions in the memory array are integrated in a second wafer , the first wafer and the second wafer are connected together by bonding.
- the bonding is to directly bond two sheets of homogeneous or heterogeneous semiconductor materials with clean surfaces and atomic level flatness through surface cleaning and activation treatment under certain conditions, and bond the wafers through van der Waals force, molecular force or even atomic force. integrated technology.
- the bottom-to-top structure of the first wafer is a substrate, a writing transistor
- the bottom-to-top structure of the second wafer is a substrate, an antiferromagnetic layer stripe film or a heavy metal layer stripe film
- the two wafers are directly electrically connected by bonding, so that each write transistor is electrically connected to each corresponding magnetic tunnel junction, which reduces the number of transistors and improves the storage density of the device.
- the size of the wafer in the embodiment of the present invention may be 1 inch, 2 inches, 3 inches, 4 inches, 6 inches, 8 inches, 12 inches, etc., which is not limited in the present invention, but the first wafer and the second wafer To ensure successful bonding in size, in particular, each write transistor is electrically connected to each corresponding magnetic tunnel junction.
- switching elements are provided on both the high-level wiring and the low-level wiring.
- the switching element includes an NMOS selection transistor, and/or a PMOS selection transistor.
- the high-level wiring and the low-level wiring are respectively interconnected with the PMOS selection transistor and the NMOS selection transistor, and each NMOS selection transistor or PMOS selection transistor can control a plurality of strip-shaped antiferromagnetic layer strips The current of the thin film or the heavy metal layer strip film.
- both the PMOS selection transistor and the NMOS selection transistor are metal oxide semiconductor transistors. In the embodiment of the present invention, they are used as open elements to control the current on the conductor layer.
- the high-level wiring can be set An NMOS selection transistor or a PMOS selection transistor, an NMOS selection transistor or a PMOS selection transistor may also be set on the low-level connection, which is not limited in the present invention.
- the conductor layer is in the shape of a long strip, the top area of which is larger than the bottom area of all the magnetic tunnel junctions, and the bottom surface shape of the magnetic tunnel junction is completely embedded between the top surface shapes of the conductor layer. middle.
- the diameter of the cylindrical tunnel junction is usually less than 50 nm, and a wiring conductor layer with a thickness of less than 5 nm is required to achieve an efficient writing process.
- the size of the metal wiring is also limited. The width is basically close to the diameter of the tunnel junction, and the length is determined by the number of magnetic tunnel junctions.
- the present invention simultaneously applies the STT and SOT effects to the magnetic tunnel junction inversion.
- the magnetic memory improves the writing speed and device reliability.
- the magnetic memory reduces the static power consumption of the circuit, reduces the number of transistors, and improves the storage density of the device.
- Embodiments of the second aspect of the present invention further provide a memory, including: a plurality of storage array groups, each storage array group including a pair of storage arrays, a high-level wiring and a low-level wiring; the storage array includes a plurality of memory cells and conductor layers arranged in an array; each memory cell comprises: a writing transistor, the first end of which is coupled with the top electrode wiring; an MTJ magnetic tunnel junction, whose end close to the reference layer is connected with the first end of the writing transistor Two-terminal coupling; one side surface of the conductor layer is coupled with one end face of all the MTJ magnetic tunnel junctions close to the free layer; wherein, the two ends of the conductor layer are respectively coupled to high-level wiring and low-level wiring wiring.
- the memory in the embodiment of the present invention simultaneously applies the STT and SOT effects to the magnetic tunnel junction inversion.
- the magnetic memory improves the writing speed and device reliability.
- the magnetic memory improves the writing speed and device reliability.
- the model of the magnetic memory reduces the static power consumption of the circuit, reduces the number of transistors, and improves the storage density of the device.
- the high-level wiring is located between a pair of memory arrays in each memory array group, and ends of the conductor layers of the pair of memory arrays that are close to each other are coupled to the high-level wiring and the ends of the conductor layers of the pair of memory arrays facing away from each other are respectively coupled to a low-level wire.
- each pair of memory arrays in the memory array may share one high-level wire.
- a three-dimensional high-density NAND-like magnetic memory has a core structure of a magnetic tunnel junction, an antiferromagnetic layer stripe film or a heavy metal layer stripe film, a writing transistor, and an NMOS and PMOS selection transistor.
- the high-level wiring Vdd and the low-level wiring GND are respectively interconnected with a PMOS and NMOS selection transistor, and each PMOS selection transistor can be interconnected with multiple conductor layers.
- there are only 4 magnetic tunnel junctions on each antiferromagnetic layer strip film or heavy metal layer strip film are only 4 magnetic tunnel junctions on each antiferromagnetic layer strip film or heavy metal layer strip film, but in practice, the magnetic tunnel junctions on each antiferromagnetic layer strip film or heavy metal layer strip film are The number is determined by the circuit drive capability and is not specified as 4.
- the write transistors used in this embodiment are vertical gate-all-around transistors.
- FIG. 4 is another schematic diagram of the manufacturing of the magnetic memory shown in FIG. 3 .
- the bottom-to-top structure of the first wafer is the substrate and the writing transistor
- the bottom-to-top structure of the second wafer is the substrate Bottom
- the low-level wiring is located between a pair of storage arrays in each storage array group, and the ends of the conductor layers of the pair of storage arrays that are close to each other are coupled to the low-level wiring and the ends of the conductor layers of the pair of memory arrays facing away from each other are respectively coupled to a high-level wire.
- each pair of memory arrays in the memory array in the embodiment of the present invention may share one low-level connection.
- another three-dimensional high-density NAND-like magnetic memory has a core structure of magnetic tunnel junction, antiferromagnetic layer stripe film or heavy metal layer stripe film, write transistor, NMOS and PMOS select transistors.
- the high-level wiring Vdd and the low-level wiring GND are respectively interconnected with a PMOS and NMOS selection transistor, and each NMOS selection transistor can be interconnected with a plurality of conductor layers.
- there are only 4 magnetic tunnel junctions on each antiferromagnetic layer strip film or heavy metal layer strip film but in practice, the magnetic tunnel junctions on each antiferromagnetic layer strip film or heavy metal layer strip film are The number is determined by the circuit drive capability and is not specified as 4.
- the write transistors used in this embodiment are vertical gate-all-around transistors.
- FIG. 6 is another schematic view of manufacturing the magnetic memory shown in FIG. 5 .
- the bottom-to-top structure of the first wafer is the substrate and the writing transistor
- the bottom-to-top structure of the second wafer is the substrate Bottom
- NMOS/PMOS selection transistor/driver circuit antiferromagnetic layer strip film or heavy metal layer strip film
- magnetic tunnel junction direct bonding between two wafers, so that each transistor is coupled with the magnetic tunnel junction .
- an embodiment of the third aspect of the present invention further provides a method for preparing a storage array, the method comprising:
- S2 forming a plurality of MTJ magnetic tunnel junctions corresponding to the writing transistors one-to-one, and coupling one end of the MTJ magnetic tunnel junctions close to the reference layer with the second end of the writing transistor;
- S4 The two ends of the conductor layer are respectively coupled to the high-level wiring and the low-level wiring.
- forming a plurality of write transistors includes: integrating the plurality of write transistors in a first wafer; forming a plurality of MTJs corresponding to the write transistors one-to-one Magnetic tunnel junctions, comprising: integrating the plurality of MTJ magnetic tunnel junctions in a second wafer; coupling one end of the MTJ magnetic tunnel junctions close to the reference layer with the second end of the writing transistor, comprising: integrating the MTJ magnetic tunnel junctions The first wafer and the second wafer are bonded.
- a fourth aspect of the present invention provides a data writing method using the storage array described in the first aspect, and the writing method includes:
- the technical effects of the memory, the method for preparing the storage array, and the method for writing data to the storage array are based on the aforementioned characteristics of the storage array of the present invention, and therefore have corresponding use effects, which are not described in detail in the present invention.
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Abstract
一种存储阵列、存储器、制备方法及写入方法,涉及磁阻式随机存取存储器存储阵列及其制造方法,所述存储阵列包括:多个阵列排布的存储单元和导体层;每个存储单元包括:写入晶体管,其第一端与顶电极接线耦接;MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接,所述存储阵列、存储器、制备方法及写入方法同时将STT和SOT效应应用于磁隧道结翻转,相对于STT-MRAM,该磁存储器提高了写入速度和器件可靠性,相对于SOT-MRAM的模型,所述磁存储器降低了电路静态功耗,减少了晶体管的数量,提高了器件存储密度。
Description
本发明涉及半导体领域,更具体的,涉及一种存储阵列、存储器、制备方法及写入方法。
磁性随机存储器(magnetic random access memory,MRAM)由于具有非易失性、抗辐照、低功耗等优点,引起了学术与工业领域极大的关注。磁性隧道结(magnetic tunnel junction,MTJ)是磁性随机存储器MRAM的基本存储单元。MTJ的核心部分由两层磁性金属层和一个夹在两层磁性金属层之间的势垒层组成。其中一个磁性金属层叫做参考层,它的磁化固定不变。另一个磁性金属层叫做自由层,它的磁化有两个稳定的取向。MTJ可呈现两种状态,即两层磁性层磁化方向互相平行(parallel,P)或者互相反平行(antiparallel,AP),使得MTJ出现低阻态或高阻态,这种效应被称为隧穿磁阻效应(tunnel magnetoresistance,TMR)。MRAM存储的基本原理就是利用隧穿磁阻效应,即高低阻态分别表示数据“0”和“1”。
一种类型的MRAM为自旋转移矩磁性随机存储器(spin transfer torque magnetoresistive RAM,STT-MRAM)。STT-MRAM的写入操作利用自旋转移矩效应翻转自由磁性层的磁化方向;读取操作通过磁性隧道结的隧穿磁阻效应进行。目前的STT-MRAM写入电流方向在写“0”和写“1”时相反。STT-MRAM写入中,MTJ由平行翻转到反平行,与反平行翻转到平行时的电流大小不一致,即STT翻转的效率不对称。另一方面,对于一晶体管MTJ的单元,因两种写入电流方向同时存在,在某种电流方向时,会出现源级退化现象。这两方面将共同导致STT-MRAM性能下降。此外STT-MRAM还受STT效应固有的翻转时间延迟限制,大大影响了STT-MRAM的写入速度。
另一种类型的MRAM为自旋轨道矩磁性随机存储器(spin orbit torque magnetoresistive RAM,SOT-MRAM)。SOT-MRAM的基本单元结构为MTJ、重金属层或铁磁层及两个访问晶体管。MTJ自下到上为自由层/势垒层/参考层/钉扎层,MTJ的自由层下方为重金属或反铁磁层,流经重金属或反铁磁层的电流能引发力矩以翻转MTJ的自由层磁化方向,实现磁写入。在这种技术下,SOT效应写入解决了写入速度的问题,但由于现有SOT-MRAM基本单元结构包括两个访问晶体管,即写入的晶体管和读取的 晶体管,且写入晶体管与读取晶体管宽度相同,难以提高集成密度。同时,晶体管的源级退化问题依然存在。
发明内容
本发明提供一种存储阵列、存储器、制备方法及写入方法,一些实施方式涉及包括磁阻式随机存取存储器存储阵列及其制造方法,所述存储阵列包括:多个阵列排布的存储单元和导体层;每个存储单元包括:写入晶体管,其第一端与顶电极接线耦接;MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线,本发明同时将STT和SOT效应应用于磁隧道结翻转,相对于STT-MRAM,该磁存储器提高了写入速度和器件可靠性,相对于SOT-MRAM的模型,该磁存储器降低了电路静态功耗,减少了晶体管的数量,提高了器件存储密度。
本发明第一方面实施方式提供一种磁阻式随机存取器的存储阵列,包括:多个阵列排布的存储单元和导体层;每个存储单元包括:
写入晶体管,其第一端与顶电极接线耦接;
MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;
所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线。
在某些实施方式中,所述存储阵列中的所有写入晶体管集成在第一晶圆中,所述存储阵列中的所有MTJ磁隧道结集成在第二晶圆中,所述第一晶圆和所述第二晶圆通过键合的方式连接在一起。
在某些实施方式中,所述高电平接线和所述低电平接线上均设置开关元件。
在某些实施方式中,所述导体层为长条形,其顶面积大于全部磁隧道结的底面积,所述磁隧道结的底面形状完全内嵌于所述导体层的顶面形状之中。
本发明第二方面实施方式提供一种存储器,包括:多个存储阵列组、每个存储阵列组包括一对存储阵列,高电平接线以及低电平接线;
所述存储阵列包括多个阵列排布的存储单元和导体层;
每个存储单元包括:
写入晶体管,其第一端与顶电极接线耦接;
MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;
所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线。
在某些实施方式中,所述高电平接线位于每个存储阵列组中的一对存储阵列之间,该一对存储阵列的导体层相互靠近的一端耦接在所述高电平接线上,并且该一对存储阵列的导体层相互背离的一端各自耦接在一低电平接线上。
在某些实施方式中,所述低电平接线位于每个存储阵列组中的一对存储阵列之间,该一对存储阵列的导体层相互靠近的一端均耦接在所述低电平接线上,并且该一对存储阵列的导体层相互背离的一端各自耦接在一高电平接线上。
本发明第三方面实施方式提供一种制备存储阵列的方法,包括:
形成多个写入晶体管,并将其第一端与顶电极接线耦接;
形成与所述写入晶体管一一对应的多个MTJ磁隧道结,并将其靠近参考层的一端与所述写入晶体管的第二端耦接;
形成一导体层,并且将其一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;
将所述导体层的两端分别耦接高电平接线和低电平接线。
在某些实施方式中,所述形成多个写入晶体管,包括:
在第一晶圆中集成所述多个写入晶体管;
所述形成与所述写入晶体管一一对应的多个MTJ磁隧道结,包括:
在第二晶圆中集成所述多个MTJ磁隧道结;
将MTJ磁隧道结靠近参考层的一端与所述写入晶体管的第二端耦接,包括:
将所述第一晶圆和所述第二晶圆键合。
本发明第四方面实施方式提供一种利用如第一方面实施方式中所述的存储阵列进行数据写入方法,包括:
导通高电平接线和所述低电平接线,以使所述存储阵列中的所有MTJ磁隧道结置为第一阻态;其中,所述第一阻态对应第一数值,与第一阻态相对的第二阻态对应第二数值;
根据写入数值串中的第二数值和第二数值所在数值串中的位置,选择对应位置MTJ磁隧道结;
导通与MTJ磁隧道结耦接的写入晶体管,并导通高电平接线和低电平接线的其中一个,以使该对应位置处的MTJ磁隧道结切换为第二阻态。
本发明的有益效果:
本发明提供一种存储阵列、存储器、制备方法及写入方法,一些实施方式涉及包括磁阻式随机存取存储器存储阵列及其制造方法,所述存储阵列包括:多个阵列排布的存储单元和导体层;每个存储单元包括:写入晶体管,其第一端与顶电极接线耦接;MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线,本发明同时将STT和SOT效应应用于磁隧道结翻转,相对于STT-MRAM,该磁存储器提高了写入速度和器件可靠性,相对于SOT-MRAM的模型,该磁存储器降低了电路静态功耗,减少了晶体管的数量,提高了器件存储密度。
为了更清楚地说明本发明实施方式或现有技术中的技术方案,下面将对实施方式或现有技术描述中所需要使用的附图作简单地介绍,显而易见地,下面描述中的附图仅仅是本发明的一些实施方式,对于本领域普通技术人员来讲,在不付出创造性劳动的前提下,还可以根据这些附图获得其他的附图。
图1为本发明实施方式中一种三维高密度类NAND磁存储器结构示意图之一;
图2为本发明实施方式中一种磁存储器的制造示意图之一;
图3为本发明实施方式中一种三维高密度类NAND磁存储器结构示意图之二;
图4为本发明实施方式中一种磁存储器的制造示意图之二;
图5为本发明实施方式中一种三维高密度类NAND磁存储器结构示意图之三;
图6为本发明实施方式中一种磁存储器的制造示意图之三;
图7为本发明实施方式中一种制备存储阵列的方法流程图;
图8为本发明实施方式中一种存储阵列进行数据写入的方法流程图。
下面将结合本发明实施方式中的附图,对本发明实施方式中的技术方案进行清楚、完整地描述,显然,所描述的实施方式仅仅是本发明一部分实施方式,而不是全部的实施方式。基于本发明中的实施方式,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施方式,都属于本发明保护的范围。
以下公开内容提供了许多用于实现本发明的不同特征的不同实施例或实例。下面描述了组件和布置的具体实例以简化本发明。当然,这些仅仅是实例,而不旨在限制本发明。例如,以下描述中,在第二部件上方或者上形成第一部件可以包括第一部件和第二部件直接接触形成的实施例,并且也可以包括在第一部件和第二部件之间可以形成额外的部件,从而使得第一部件和第二部件可以不直接接触的实施例。此外,本发明可在各个实施例中重复参考标号和/或字符。该重复是为了简单和清楚的目的,并且其本身不指示所讨论的各个实施例和/或配置之间的关系。
而且,为便于描述,在此可以使用诸如“在…之下”、“在…下方”、“下部”、“在…之上”、“上部”等空间相对术语,以描述如图所示的一个元件或部件与另一个(或另一些)原件或部件的关系。除了图中所示的方位外,空间相对术语旨在包括器件在使用或操作中的不同方位。
现有的STT-MRAM,即使用STT效应翻转MTJ的自由层磁化方向,其写入电流方向在写“0”和写“1”时相反。一方面,STT-MRAM写入中,MTJ由平行翻转到反平行,与反平行翻转到平行时时的电流大小不一致,即STT翻转的效率不对称;另一方面,对于一晶体管一MTJ的单元,因两种写入电流方向同时存在,在某种电流方向时,会出现源级退化现象。这两方面将共同导致STT-MRAM性能下降。
现有的SOT-MRAM,其基本结构为MTJ、重金属层或铁磁层及两个访问晶体管,即写入的晶体管和读取的晶体管,在这种技术下,写入电流远大于读取电流,但由于布局限制,写入晶体管与读取晶体管宽度相同,难以提高集成度。同时,晶体管源级退化问题依然存在。
为了解决上述问题,本发明第一方面实施方式提供一种磁阻式随机存取器的存储阵列,包括:多个阵列排布的存储单元和导体层;每个存储单元包括:写入晶体管,其第一端与顶电极接线耦接;MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线。
本发明实施方式中的存储阵列同时将STT和SOT效应应用于磁隧道结翻转,相对于STT-MRAM,该磁存储器提高了写入速度和器件可靠性,相对于SOT-MRAM的模型,该磁存储器降低了电路静态功耗,减少了晶体管的数量,提高了器件存储密度。
可以理解,本发明实施方式中的“耦接”,可以包括第一部件和第二部件直接接触形成的实施方式,并且也可以包括在第一部件和第二部件之间可以形成额外的部件,从而使得第一部件和第二部件可以不直接接触的实施方式。
所述写入晶体管包括但不限于常规晶体管、隧穿场效应管、FinFET、垂直全环栅晶体管。
所述磁隧道结的形状包括但不限于正方形、长方形、圆形或椭圆形。
本发明实施方式中所使用的半导体工艺加工主要包括:深紫外光刻(DUV),电子束直写(EBL)等曝光技术;电感耦合等离子刻蚀(ICP),电容耦合等离子刻蚀(CCP),离子束刻蚀(IBE)等刻蚀技术,等离子增强化学气相沉积(PECVD),化学气相沉积(CVD)等介质沉积技术;磁控溅射(Magnetron sputtering)等金属沉积技术。
图1为本发明实施方式中一种三维高密度类NAND磁存储器结构示意图之一,所述NAND磁存储器是一种比硬盘驱动器更好的存储方案,该磁存储器包括存储部分和控制部分,存储部分包括磁隧道结MTJ及导体层;控制部分包括高电平接线Vdd、低电平接线GND以及写入晶体管。所述导体层上制造多个磁隧道结,磁隧道结的结构从下至上主要结构依次为第一铁磁金属层、第一氧化物层、第二铁磁金属层、第一合成反铁磁层、第X顶端电极,第X个磁隧道结经第X顶端电极与第X个写入晶体管的源级或漏级互联,每个磁隧道结和写入晶体管共同代表一个存储单元。
所述导体层为反铁磁层条状薄膜或重金属层条状薄膜,包括但不限于铂、钽、钨、铱锰、铂锰等。
所述第一铁磁金属层和第二铁磁金属层,厚度分别相同或不相同,为0~3nm,两层磁性层均由磁性材料组成,材料包括但不限于单质铁磁材料,如铁、钴、镍等;或混合金属材料,如钴铁、钴铁硼、镍铁等,其中混合金属材料的各元素比例不同。结构包括但不限于单层膜、双层膜及多层膜。
当然此处仅仅示出该实施例的具体尺寸和材料构成的其中一种形式,本领域技术人员可以理解,具体的厚度以及材料的选取不会形成实质性的影响,在不影响本申请的主体构思的前提下,本领域技术人员有能力在不付出创造性劳动的基础上,进行其他厚度以及材料的选取,此处不再赘述。
如图2所示,在一些优选的实施方式中,所述存储阵列中的所有写入晶体管集成在第一晶圆中,所述存储阵列中的所有MTJ磁隧道结集成在第二晶圆中,所述第一晶圆和所述第二晶圆通过键合的方式连接在一起。
可以理解,所述键合是将两片表面清洁、原子级平整的同质或异质半导体材料经表面清洗和活化处理,在一定条件下直接结合,通过范德华力、分子力甚至原子力使晶片键合成为一体的技术。
在本实施方式中,第一晶圆由下至上的结构为衬底、写入晶体管,第二晶圆由下至上的结构为衬底、反铁磁层条状薄膜或重金属层条状薄膜、磁隧道结,两个晶圆间使用键合方式直接电连接,使得每个写入晶体管与每个对应的磁隧道结电连接在一起,减少了晶体管的数量,提高了器件存储密度。
本发明实施方式中的晶圆,尺寸可以是1英寸,2英寸,3英寸,4英寸,6英寸,8英寸,12英寸等,本发明不做限制,但第一晶圆和第二晶圆要保证尺寸上可以键合成功,尤其使每个写入晶体管与每个对应的磁隧道结电连接在一起。
在一些优选的实施方式中,所述高电平接线和所述低电平接线上均设置开关元件。
优选的,所述开关元件包括NMOS选择晶体管,和/或PMOS选择晶体管。请继续结合图1,所述高电平接线和所述低电平接线分别与PMOS选择晶体管和NMOS选择晶体管互联,每个NMOS选择晶体管或PMOS选择晶体管可控制多个条状反铁磁层条状薄膜或重金属层条状薄膜的电流。
当然,PMOS选择晶体管和NMOS选择晶体管均为金属氧化物半导体管,在本发明的实施方式中作为开个元件来控制导体层上的电流,在具体应用中,所述高电平接线上可以设置NMOS选择晶体管或PMOS选择晶体管,所述低电平接线上也可以设置NMOS选择晶体管或PMOS选择晶体管,本发明不做限制。
在一些优选的实施方式中,所述导体层为长条形,其顶面积大于全部磁隧道结的底面积,所述磁隧道结的底面形状完全内嵌于所述导体层的顶面形状之中。
可以理解,为实现磁随机存储器高密度存储及高效的自旋轨道矩写入,圆柱形隧道结的直径通常小于50nm,实现高效的写入过程需要厚度低于5nm的配线导体层,同时为了降低极薄配线层带来的高电阻,金属配线尺寸上同样受到限制,宽度基本要接近隧道结直径,长度依据磁隧道结的个数决定。
当然此处仅仅示出该实施例的具体尺寸和材料构成的其中一种形式,本领域技术人员可以理解,具体的尺寸以及材料的选取不会形成实质性的影响,在不影响本发明的主体构思的前提下,本领域技术人员有能力在不付出创造性劳动的基础上,可以进行其他尺寸以及材料的选取,此处不再赘述。
从上述实施方式中可以知晓,本发明同时将STT和SOT效应应用于磁隧道结翻转,相对于STT-MRAM,该磁存储器提高了写入速度和器件可靠性,相对于SOT-MRAM的模型,该磁存储器降低了电路静态功耗,减少了晶体管的数量,提高了器件存储密度。
本发明第二方面实施方式还提供了一种存储器,包括:多个存储阵列组、每个存储阵列组包括一对存储阵列,高电平接线以及低电平接线;所述存储阵列包括多个阵列排布的存储单元和导体层;每个存储单元包括:写入晶体管,其第一端与顶电极接线耦接;MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线。
基于相同的发明构思,本发明实施方式中的存储器同时将STT和SOT效应应用于磁隧道结翻转,相对于STT-MRAM,该磁存储器提高了写入速度和器件可靠性,相对于SOT-MRAM的模型,该磁存储器降低了电路静态功耗,减少了晶体管的数量,提高了器件存储密度。
在一些优选的实施方式中,所述高电平接线位于每个存储阵列组中的一对存储阵列之间,该一对存储阵列的导体层相互靠近的一端耦接在所述高电平接线上,并且该一对存储阵列的导体层相互背离的一端各自耦接在一低电平接线上。
可以理解,为了提高晶体管的集成密度,本发明实施方式中存储阵列中每对存储阵列可以共用一个高电平接线。
如图3所示,一种三维高密度类NAND磁存储器,核心结构为磁隧道结、反铁磁层条状薄膜或重金属层条状薄膜、写入晶体管、NMOS和PMOS选择晶体管。所述高电平接线Vdd和低电平接线GND分别与一个PMOS和NMOS选择晶体管互联,每个PMOS选择晶体管可以与多个导体层互联。示意图中,每条反铁磁层条状薄膜或重金属层条状薄膜上仅有4个磁隧道结,但实际中每条反铁磁层条状薄膜或重金属层条状薄膜上磁隧道结的个数由电路驱动能力确定,不指定为4个。该实施例使用的写入晶体管为垂直全环栅晶体管。
图4为图3所示的磁存储器的另一种制造示意图,在此制造中,第一晶圆由下至上的结构为衬底、写入晶体管,第二晶圆由下至上的结构为衬底、NMOS选择晶体管,和/或PMOS选择晶体管、反铁磁层条状薄膜或重金属层条状薄膜、磁隧道结,两个晶圆间直接键合,使得每个写入晶体管与磁隧道结耦接在一起。
在一些优选的实施方式中,所述低电平接线位于每个存储阵列组中的一对存储阵列之间,该一对存储阵列的导体层相互靠近的一端均耦接在所述低电平接线上,并且该一对存储阵列的导体层相互背离的一端各自耦接在一高电平接线上。
同样的,可以理解,为了提高晶体管的集成密度,本发明实施方式中存储阵列中每对存储阵列可以共用一个低电平接线。
如图5所示,另一种三维高密度类NAND磁存储器,核心结构为磁隧道结、反铁磁层条状薄膜或重金属层条状薄膜、写入晶体管、NMOS和PMOS选择晶体管。高电平接线Vdd和低电平接线GND分别与一个PMOS和NMOS选择晶体管互联,每个NMOS选择晶体管可以与多个导体层互联。示意图中,每条反铁磁层条状薄膜或重金属层条状薄膜上仅有4个磁隧道结,但实际中每条反铁磁层条状薄膜或重金属层条状薄膜上磁隧道结的个数由电路驱动能力确定,不指定为4个。该实施例使用的写入晶体管为垂直全环栅晶体管。
图6为图5所示的磁存储器的另一种制造示意图,在此制造中,第一晶圆由下至上的结构为衬底、写入晶体管,第二晶圆由下至上的结构为衬底、NMOS/PMOS选择晶体管/驱动电路、反铁磁层条状薄膜或重金属层条状薄膜、磁隧道结,两个晶圆间直接键合,使得每个晶体管与磁隧道结耦接在一起。
如图7所示,本发明第三方面实施方式还提供了一种用于制备存储阵列的方法,所述方法包括:
S1:形成多个写入晶体管,并将其第一端与顶电极接线耦接;
S2:形成与所述写入晶体管一一对应的多个MTJ磁隧道结,并将其靠近参考层的一端与所述写入晶体管的第二端耦接;
S3:形成一导体层,并且将其一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;
S4:将所述导体层的两端分别耦接高电平接线和低电平接线。
在一些优选的实施方式中,所述形成多个写入晶体管,包括:在第一晶圆中集成所述多个写入晶体管;所述形成与所述写入晶体管一一对应的多个MTJ磁隧道结,包括:在第二晶圆中集成所述多个MTJ磁隧道结;将MTJ磁隧道结靠近参考层的一端与所述写入晶体管的第二端耦接,包括:将所述第一晶圆和所述第二晶圆键合。
如图8所示,进一步的,本发明第四方面实施方式提供了一种利用如第一方面实施方式中所述的存储阵列进行数据写入方法,所述写入方法包括:
S21:导通高电平接线和所述低电平接线,以使所述存储阵列中的所有MTJ磁隧道结置为第一阻态;其中,所述第一阻态对应第一数值,与第一阻态相对的第二阻态对应第二数值;
S22:根据写入数值串中的第二数值和第二数值所在数值串中的位置,选择对应位置MTJ磁隧道结;
S23:导通与MTJ磁隧道结耦接的写入晶体管,并导通高电平接线和低电平接线的其中一个,以使该对应位置处的MTJ磁隧道结切换为第二阻态。
请继续结合图1,首先在高电平接线Vdd和低电平接线GND之间施加单向电流,将所有磁隧道结写为高电阻状态,即所有磁隧道结全部表示数据“0”;然后根据写入数值串中的第二数值“1”和其所在数值串中的位置,选择对应位置MTJ磁隧道结;最后再导通高电平接线和低电平接线的其中一个,使高电平接线和低电平接线的其中一个与第X顶端电极之间形成单向电流,以使该对应位置处的MTJ磁隧道结切换为第二阻态“1”。
可以理解,导通高电平接线和低电平接线中的任一个,都可以形成基于STT效应的写入方式。
上述存储器、存储阵列的制备方法以及存储阵列数据写入方法的技术效果都是基于本发明前述的存储阵列的特性,因此具有对应的使用效果,本发明不做赘述。
在本说明书的描述中,参考术语“一个实施方式”、“一些实施方式”、“示例”、“具体示例”、或“一些示例”等的描述意指结合该实施方式或示例描述的具体特征、结构、材料或者特点包含于本说明书实施方式的至少一个实施方式或示例中。在本说明书中,对上述术语的示意性表述不必须针对的是相同的实施方式或示例。
此外,在不相互矛盾的情况下,本领域的技术人员可以将本说明书中描述的不同实施方式或示例以及不同实施方式或示例的特征进行结合和组合。以上所述仅为本说明书实施方式的实施方式而已,并不用于限制本说明书实施方式。对于本领域技术人员来说,本说明书实施方式可以有各种更改和变化。凡在本说明书实施方式的精神和原理之内所作的任何修改、等同替换、改进等,均应包含在本说明书实施方式的权利要求范围之内。
Claims (10)
- 一种存储阵列,其特征在于,包括:多个阵列排布的存储单元和导体层;每个存储单元包括:写入晶体管,其第一端与顶电极接线耦接;MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线。
- 根据权利要求1所述的存储阵列,其特征在于,所述存储阵列中的所有写入晶体管集成在第一晶圆中,所述存储阵列中的所有MTJ磁隧道结集成在第二晶圆中,所述第一晶圆和所述第二晶圆通过键合的方式连接在一起。
- 根据权利要求1所述的存储阵列,其特征在于,所述高电平接线和所述低电平接线上均设置开关元件。
- 根据权利要求1所述的存储阵列,其特征在于,所述导体层为长条形,其顶面积大于全部磁隧道结的底面积,所述磁隧道结的底面形状完全内嵌于所述导体层的顶面形状之中。
- 一种存储器,其特征在于,包括:多个存储阵列组、每个存储阵列组包括一对存储阵列,高电平接线以及低电平接线;所述存储阵列包括多个阵列排布的存储单元和导体层;每个存储单元包括:写入晶体管,其第一端与顶电极接线耦接;MTJ磁隧道结,其靠近参考层的一端与所述写入晶体管的第二端耦接;所述导体层的一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;其中,所述导体层的两端分别耦接高电平接线和低电平接线。
- 根据权利要求5所述的存储器,其特征在于,所述高电平接线位于每个存储阵列组中的一对存储阵列之间,该一对存储阵列的导体层相互靠近的一端耦接在所述高电平接线上,并且该一对存储阵列的导体层相互背离的一端各自耦接在一低电平接线上。
- 根据权利要求5所述的存储器,其特征在于,所述低电平接线位于每个存储阵列组中的一对存储阵列之间,该一对存储阵列的导体层相互靠近的一端均耦接在所述低电平接线上,并且该一对存储阵列的导体层相互背离的一端各自耦接在一高电平接线上。
- 一种制备存储阵列的方法,其特征在于,包括:形成多个写入晶体管,并将其第一端与顶电极接线耦接;形成与所述写入晶体管一一对应的多个MTJ磁隧道结,并将其靠近参考层的一端与所述写入晶体管的第二端耦接;形成一导体层,并且将其一侧表面与所有所述MTJ磁隧道结靠近自由层的一端端面耦接;将所述导体层的两端分别耦接高电平接线和低电平接线。
- 根据权利要求8所述的方法,其特征在于,所述形成多个写入晶体管,包括:在第一晶圆中集成所述多个写入晶体管;所述形成与所述写入晶体管一一对应的多个MTJ磁隧道结,包括:在第二晶圆中集成所述多个MTJ磁隧道结;将MTJ磁隧道结靠近参考层的一端与所述写入晶体管的第二端耦接,包括:将所述第一晶圆和所述第二晶圆键合。
- 一种利用如权利要求1所述的存储阵列进行数据写入方法,其特征在于,包括:导通高电平接线和所述低电平接线,以使所述存储阵列中的所有MTJ磁隧道结置为第一阻态;其中,所述第一阻态对应第一数值,与第一阻态相对的第二阻态对应第二数值;根据写入数值串中的第二数值和第二数值所在数值串中的位置,选择对应位置MTJ磁隧道结;导通与MTJ磁隧道结耦接的写入晶体管,并导通高电平接线和低电平接线的其中一个,以使该对应位置处的MTJ磁隧道结切换为第二阻态。
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