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一种具有间隔层的稀土‑过渡合金复合材料的制备方法 【EN】A kind of preparation method of the rare-earth transition alloy composite materials with wall

申请(专利)号:CN201710601531.X国省代码:福建 35
申请(专利权)人:【中文】华侨大学【EN】Huaqiao University
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摘要:
【中文】本发明公开一种具有间隔层的稀土‑过渡合金复合材料的制备方法,将稀土贴片与铁钴合金靶相贴合形成复合镶嵌靶,先采用磁控溅射复合镶嵌靶或者三元合金靶,在基片上生长20~50nm厚的第一层稀土‑过渡合金薄膜(磁性薄膜层I),然后溅射0.5~2.5nm厚的金属间隔层或氧化物间隔层(间隔层),最后继续溅射复合镶嵌靶或者三元合金靶,在间隔层上生长7~15nm厚的第二层稀土‑过渡合金薄膜(磁性薄膜层II),得到的是一种具有间隔层的同一种亚铁磁稀土‑过渡合金(TbFeCo或者DyFeCo)构成的复合材料。该制备方法制备得到的复合材料性能稳定,该复合材料的结构与垂直磁电器件完全兼容,可以作为一种新型的磁电子学器件材料用于垂直自旋阀或磁隧道结器件中。 【EN】Paragraph:The present invention discloses a kind of preparation method of the rare-earth transition alloy composite materials with wall, rare earth paster and ferrocobalt target are fitted to form combined tessera target, first use magnetron sputtering combined tessera target or ternary alloy three-partalloy target, the thick first layer rare-earth transition alloy firms (laminated magnetic film I) of 20~50nm are grown on substrate, then the thick metal spacing layers of 0.5~2.5nm or oxide spacers (wall) are sputtered, finally continue to sputter combined tessera target or ternary alloy three-partalloy target, the thick second layer rare-earth transition alloy firms (laminated magnetic film II) of 7~15nm are grown on wall, what is obtained is the composite that a kind of same Ferrimagnetic rare-earth transition alloy (TbFeCo or DyFeCo) with wall is formed.The composite property that the preparation method is prepared is stable, and the structure of the composite and vertical magnetoelectronic devices are completely compatible, can be used for as a kind of new magnetoelectronic devices material in vertical spin valve or magnetic tunnel device.Image:201710601531.GIF

主权项:
【中文】1.一种具有间隔层的稀土-过渡合金复合材料的制备方法,其特征在于:包括以下步骤: (1)将稀土贴片与铁钴合金靶组成的复合镶嵌靶或者三元合金靶作为磁控溅射的靶材,安装固定在磁控溅射室的溅射靶座上,所述稀土贴片为Tb贴片或者Dy贴片,所述三元合金靶为TbFeCo合金靶或者DyFeCo合金靶,所述复合镶嵌靶中稀土贴片的数量以及固定在所述溅射靶座的位置或者所述三元合金靶中的稀土含量使得制备得到的稀土-过渡合金复合材料中的稀土元素成分为25~27.5%; (2)将清洗烘干后的基片安置固定于磁控溅射室的基片台上,调整靶基距为4~8cm; (3)将溅射真空室抽真空达到真空度1×10Pa以下,通入纯度≥99.99%的氩气作为工作气体,控制氩气的进气流量在30~100sccm范围内; (4)在溅射工作气压0.2~1.0Pa的条件下,对所述靶材预溅射10~30min; (5)调节基片台每分钟旋转5~15圈,打开基片台和溅射靶座之间的挡板,以1.5~6.5W/cm的溅射功率密度溅射所述靶材,溅射速率为0.1~0.3nm/s,控制溅射时间使得在所述基片上得到20~50nm厚的稀土-过渡合金薄膜,形成带有第一层稀土-过渡合金薄膜的基片; (6)然后在所述带有第一层稀土-过渡合金薄膜的基片上溅射间隔层,控制溅射时间使得生长的所述间隔层的厚度在0.5~2.5nm,形成带有间隔层和第一层稀土-过渡合金薄膜的基片,所述间隔层为金属间隔层或者氧化物间隔层; (7)最后在所述带有间隔层和第一层稀土-过渡合金薄膜的基片上继续溅射所述靶材,控制溅射时间使得在所述间隔层上生长的第二层稀土-过渡合金薄膜的厚度为7~15nm,得到所述具有间隔层的稀土-过渡合金复合材料。 【EN】A kind of 1. preparation method of the rare earth-transition alloy composite materials with wall, it is characterised in that:Including following step Suddenly: (1) target using the combined tessera target or ternary alloy three-partalloy target of rare earth paster and ferrocobalt target composition as magnetron sputtering Material, it is fixed on the sputtering target stand of magnetron sputtering chamber, the rare earth paster is Tb pasters or Dy pasters, and the ternary is closed Gold target is TbFeCo alloy target or DyFeCo alloys targets, the quantity of the combined tessera target middle rare earth paster and is fixed on institute The content of rare earth in the position for sputtering target stand or the ternary alloy three-partalloy target is stated so that the rare earth-transition alloy being prepared is compound Rare earth elements in material are 25~27.5%; (2) the substrate placement after cleaning, drying is fixed on the chip bench of magnetron sputtering chamber, adjustment target-substrate distance is 4~8cm; (3) sputtering vacuum chamber is reached into vacuum 1 × 10Below Pa, the argon gas of purity >=99.99% is passed through as work Make gas, control the charge flow rate of argon gas in the range of 30~100sccm; (4) under conditions of 0.2~1.0Pa of operating air pressure is sputtered, to 10~30min of the target pre-sputtering; (5) the chip bench circle of rotation 5~15 per minute is adjusted, chip bench is opened and sputters the baffle plate between target stand, with 1.5~ 6.5W/cmSputtering power density sputter the target, sputter rate be 0.1~0.3nm/s, controls sputtering time to cause The thick rare earth-transition alloy firms of 20~50nm are obtained on the substrate, are formed with first layer rare earth-transition alloy firm Substrate; (6) wall and then on the substrate with first layer rare earth-transition alloy firm is sputtered, control sputtering time makes The thickness for the wall that must be grown carries wall and first layer rare earth-transition alloy firm in 0.5~2.5nm, formation Substrate, the wall is metal spacing layer or oxide spacers; (7) finally continue to sputter the target on the substrate with wall and first layer rare earth-transition alloy firm, Sputtering time is controlled so that the thickness of the second layer rare earth-transition alloy firm grown on the wall is 7~15nm, is obtained To the rare earth-transition alloy composite materials with wall.


说明书

【中文】

一种具有间隔层的稀土-过渡合金复合材料的制备方法

技术领域

本发明属于磁自旋电子学及磁记录技术材料领域,涉及的是一种垂直磁自旋电子器件复合薄膜材料的制备方法,具体涉及的是一种具有间隔层的稀土-过渡合金复合材料的制备方法。

背景技术

近年来,垂直自旋阀和磁隧道结等磁电器件由于具有高密度的优势以及比面内器件具有更好的热稳定性的特点而成为本领域的研究发展方向。其中,基于垂直磁隧道结的磁存储器被认为是下一代高密度非易失性存储器的代表技术之一。垂直磁隧道结中自由层和参考层等基本功能层都要求是具有易轴垂直膜面的材料。故此,寻找垂直易轴薄膜及其简单生长方法成为制备高密度磁电器件的关键。

传统磁光记录稀土-过渡族合金薄膜如TbFeCo和DyFeCo合金材料由于具有大垂直磁各向异性及高的热稳定性好,当前也广泛用于高密度磁电器件领域。这种亚铁磁合金薄膜材料中稀土元素(Tb或者Dy)与过渡元素(FeCo)子晶格的磁矩呈现反平行排列,导致这类材料中可能存在一个特定的补偿点成分,对应于这个补偿点成分合金薄膜的矫顽力为无限大。易轴垂直膜面的稀土-过渡合金薄膜成分一般位于补偿点成分附近一个不大的成分区域内。室温时合金薄膜材料中稀土元素子晶格的磁矩大于过渡族元素子晶格的磁矩则合金薄膜为富稀土相,反之则为富过渡相。垂直磁电器件件要求稀土-过渡族合金薄膜具有较大差异的垂直矫顽力,以满足器件中自由层(矫顽力小,磁化方向易随外场方向)和钉扎层(矫顽力大,磁化方向不易随外场方向变动)等不同功能层的要求。寻找具有大差异垂直反转场的稀土-过渡合金薄膜材料的制备方法,在当前高密度磁自旋电子学器件特别是电流直接诱导磁化反转等新型低功耗信息存储器领域具有重要意义,并有可能产生巨大的经济效益。

发明内容

本发明的目的在于提供一种具有间隔层的稀土-过渡合金复合材料的制备方法,制备工艺简单,制备得到的复合材料性能稳定,该复合材料的结构与垂直磁电器件完全兼容,可以作为一种新型的磁电子学器件材料用于垂直自旋阀或磁隧道结器件中。

为了达成上述目的,本发明的解决方案是:

一种具有间隔层的稀土-过渡合金复合材料的制备方法,包括以下步骤:

(1)将稀土贴片与铁钴合金靶组成的复合镶嵌靶或者三元合金靶作为磁控溅射的靶材,安装固定在磁控溅射室的溅射靶座上,所述稀土贴片为Tb贴片或者Dy贴片,所述三元合金靶为TbFeCo合金靶或者DyFeCo合金靶,所述复合镶嵌靶中稀土贴片的数量以及固定在所述溅射靶座的位置或者所述三元合金靶中的稀土含量使得制备得到的稀土-过渡合金复合材料中的稀土元素成分为25~27.5%(富稀土);

(2)将清洗烘干后的基片安置固定于磁控溅射室的基片台上,调整靶基距为4~8cm;

(3)将溅射真空室抽真空达到真空度1×10-5Pa以下,通入纯度≥99.99%的氩气作为工作气体,控制氩气的进气流量在30~100sccm范围内;

(4)在溅射工作气压0.2~1.0Pa的条件下,对所述靶材预溅射10~30min;

(5)调节基片台每分钟旋转5~15圈,打开基片台和溅射靶座之间的挡板,以1.5~6.5W/cm2的溅射功率密度溅射所述靶材,溅射速率为0.1~0.3nm/s,控制溅射时间使得在所述基片上得到20~50nm厚的稀土-过渡合金薄膜,形成带有第一层稀土-过渡合金薄膜的基片;

(6)然后在所述带有第一层稀土-过渡合金薄膜的基片上溅射间隔层,控制溅射时间使得生长的所述间隔层的厚度在0.5~2.5nm,形成带有间隔层和第一层稀土-过渡合金薄膜的基片,所述间隔层为金属间隔层或者氧化物间隔层;

(7)最后在所述带有间隔层和第一层稀土-过渡合金薄膜的基片上继续溅射所述靶材,控制溅射时间使得在所述间隔层上生长的第二层稀土-过渡合金薄膜的厚度为7~15nm,得到所述具有间隔层的稀土-过渡合金复合材料。

步骤(1)中,所述稀土贴片为呈等腰三角形的纯度≥99.9%的稀土贴片,所述铁钴合金靶的纯度≥99.9%,各片所述稀土贴片以所述铁钴合金靶的圆心为中心点贴在所述铁钴合金靶上,形成溅射用的所述复合镶嵌靶。

步骤(2)中,所述基片为单晶Si基片或者典型商用带热氧化层单晶Si基片。

步骤(4)中,在预溅射所述靶材前,先在所述基片上溅射金属缓冲层或者氧化物缓冲层,控溅射时间使得所述金属缓冲层或者氧化物缓冲层的厚度为0.5~2.5nm,所述金属缓冲层为Ta缓冲层、Ru缓冲层、Cu缓冲层、Pd缓冲层或者Pt缓冲层,所述氧化物缓冲层为SiO2缓冲层、MgO缓冲层或者Al2O3缓冲层。

步骤(6)中,所述金属间隔层为Ta间隔层、Ru间隔层、Cu间隔层、Pd间隔层或者Pt间隔层,所述氧化物间隔层为SiO2间隔层、MgO间隔层或者Al2O3间隔层。

步骤(6)中,在所述带有第一层稀土-过渡合金薄膜的基片上通过直流或者射频溅射所述金属间隔层,在所述带有第一层稀土-过渡合金薄膜的基片上通过射频溅射所述氧化物间隔层。

步骤(7)中,在得到的所述稀土-过渡合金复合材料上通过直流或者射频溅射保护层,以防止氧化,控制溅射时间使得所述保护层的厚度为2~20nm,所述保护层为Ta保护层、Ru保护层、Cu保护层、Pd保护层或者Pt保护层。

在磁记录技术材料领域中,广泛用于自旋阀和磁性隧道结等磁电器件中的磁性多层膜结构,通过非磁性间隔层产生交换耦合的作用可使相邻磁性层的磁化强度呈现平行或者反平行的排列,并且可以在一定大小的外场范围内维持磁状态稳定。

采用上述技术方案后,本发明一种具有间隔层的稀土-过渡合金复合材料的制备方法,制备得到的是一种具有间隔层的同一种亚铁磁稀土-过渡合金构成的复合结构材料,主要由磁性薄膜层I/间隔层/磁性薄膜层II构成。与间隔层相邻的是两个不同厚度的磁性薄膜层,需要由同一种亚铁磁稀土-过渡合金材料(TbFeCo或者DyFeCo)制备,可以通过固定靶材中稀土元素贴片的数量以及位置,或者使用固定比例成分的三元合金靶材来实现。与间隔层相邻的两个不同厚度的磁性薄膜层的磁矩方向可以平行或者反平行排列,并且可以在一定大小的外场范围内维持这种稳定状态。通过调整该复合材料中两磁性薄膜层的厚度实现不同的富相,利用层间交换耦合作用产生的界面畴壁能扩大两磁性薄膜层磁化反转场的变化差异,具有大差异磁化反转场的该稀土-过渡合金复合材料可直接用于垂直自旋阀或磁隧道结器件中。

本发明一种具有间隔层的稀土-过渡合金复合材料的制备方法,具有制备方法简单、重复性好和成本低廉的特点,制备得到的复合材料性能稳定,该复合材料的结构与垂直磁电器件完全兼容,可以作为一种新型的磁电子学器件材料用于垂直自旋阀或磁隧道结器件中。

附图说明

图1为TbFeCo(20nm)/Pd(2nm)/TbFeCo(10nm)复合材料的主反常霍尔曲线以及小反常霍尔曲线;

图2为TbFeCo(20nm)/Pd(1nm)/TbFeCo(7.5nm)复合材料的反常霍尔曲线。

具体实施方式

为了进一步解释本发明的技术方案,下面通过具体实施例来对本发明进行详细阐述。

实施例一

一、复合材料的制备

一种具有间隔层的稀土-过渡合金复合材料的制备方法,包括以下步骤:

(1)将四片呈等腰三角形的高纯度(纯度为99.95%)的Tb贴片贴在半径为1英寸的高纯度(纯度为99.9%)的铁钴合金靶上,形成溅射用的复合镶嵌靶,各片Tb贴片以铁钴合金靶的圆心为中心点分布在铁钴合金靶上,Tb贴片的顶角为28°,Tb贴片的腰长为2cm,厚度为2mm;

(2)将复合镶嵌靶作为磁控溅射的靶材,安装固定在磁控溅射室的溅射靶座上;

(3)对单晶Si基片依次用丙酮、酒精、异丙醇超声清洗后烘干,将烘干处理后的单晶Si基片安置固定于磁控溅射室的基片台上,调整靶基距为6.5cm;

(4)将溅射真空室抽真空达到真空度为1×10-5Pa,通入高纯度的氩气(纯度为99.999%)作为工作气体,控制氩气的进气流量在60sccm;

(5)调整闸板阀关闭的程度,使溅射工作气压稳定并维持在0.6Pa,先以1.48W/cm2的溅射功率密度对单晶Si基片射频溅射1nm厚度的MgO缓冲层,溅射速率为0.022nm/s,溅射时间为45s,得到具有MgO缓冲层的单晶Si基片,然后对复合镶嵌靶预溅射20min;

(6)调节基片台每分钟旋转10圈,打开基片台和溅射靶座之间的挡板,以5.9W/cm2的溅射功率密度溅射复合镶嵌靶,溅射速率为0.167nm/s,溅射时间为120s,在单晶Si基片上得到20nm厚的稀土-过渡合金薄膜,形成带有第一层稀土-过渡合金薄膜的单晶Si基片;

(7)然后在带有第一层稀土-过渡合金薄膜的单晶Si基片上直流溅射Pd间隔层,溅射速率为0.125nm/s,溅射时间为16s,使得生长的Pd间隔层的厚度为2nm,形成带有间隔层和第一层稀土-过渡合金薄膜的单晶Si基片;

(8)最后在带有间隔层和第一层稀土-过渡合金薄膜的单晶Si基片上继续溅射复合镶嵌靶,溅射速率为0.167nm/s,溅射时间为60s,使得在间隔层上生长的第二层稀土-过渡合金薄膜的厚度为10nm,得到具有间隔层的稀土-过渡合金复合材料,记为TbFeCo(20nm)/Pd(2nm)/TbFeCo(10nm)复合材料,其稀土元素成分为~26%。

二、性能测试

该TbFeCo(20nm)/Pd(2nm)/TbFeCo(10nm)复合材料的磁特性表征如图1所示,结果表明:溅射制备得到的具有10nm厚度和20nm厚度的TbFeCo磁性薄膜层的磁特性分别表现为富过渡和富稀土相,其垂直磁化反转场分别为8.5kOe和2.8kOe,差值为5.7kOe,其中,通过仅反转20nm的TbFeCo层的小反常霍尔回线测量确认了主反常霍尔曲线中高电平平台也是一个稳定磁状态。

因此,通过调整该复合材料中两磁性薄膜层的厚度实现不同的富相,两个不同厚度的磁性薄膜层的磁矩方向可以平行或者反平行排列(对应于主反常霍尔回线中的4个平台磁状态),利用层间交换耦合作用产生的界面畴壁能扩大两磁性薄膜层磁化反转场的变化差异,并且可以在一定大小的外场范围内维持这种稳定磁状态。

实施例二

一、复合材料的制备

一种具有间隔层的稀土-过渡合金复合材料的制备方法,包括以下步骤:

(1)将四片呈等腰三角形的高纯度(纯度为99.95%)的Tb贴片贴在半径为1英寸的高纯度(纯度为99.9%)的铁钴合金靶上,形成溅射用的复合镶嵌靶,各片Tb贴片以铁钴合金靶的圆心为中心点分布在铁钴合金靶上,Tb贴片的顶角为28°,Tb贴片的腰长为2cm,厚度为2mm;

(2)将复合镶嵌靶作为磁控溅射的靶材,安装固定在磁控溅射室的溅射靶座上;

(3)对典型商用带300nm热氧化SiO2层的单晶Si基片依次用丙酮、酒精、异丙醇超声清洗后烘干,将烘干处理后的单晶Si基片安置固定于磁控溅射室的基片台上,调整靶基距为6.5cm;

(4)将溅射真空室抽真空达到真空度为1×10-5Pa,通入高纯度的氩气(纯度为99.999%)作为工作气体,控制氩气的进气流量在60sccm;

(5)调整闸板阀关闭的程度,使溅射工作气压稳定并维持在0.6Pa,对复合镶嵌靶预溅射20min;

(6)调节基片台每分钟旋转10圈,打开基片台和溅射靶座之间的挡板,以5.9W/cm2的溅射功率密度溅射复合镶嵌靶,溅射速率为0.167nm/s,溅射时间为120s,在单晶Si基片上得到20nm厚的稀土-过渡合金薄膜,形成带有第一层稀土-过渡合金薄膜的单晶Si基片;

(7)然后在带有第一层稀土-过渡合金薄膜的单晶Si基片上射频溅射Pd间隔层,溅射速率为0.125nm/s,溅射时间为8s,使得生长的Pd间隔层的厚度为1nm,形成带有间隔层和第一层稀土-过渡合金薄膜的单晶Si基片;

(8)最后在带有间隔层和第一层稀土-过渡合金薄膜的单晶Si基片上继续溅射复合镶嵌靶,溅射速率为0.167nm/s,溅射时间为45s,使得在间隔层上生长的第二层稀土-过渡合金薄膜的厚度为7.5nm,得到具有间隔层的稀土-过渡合金复合材料,记为TbFeCo(20nm)/Pd(1nm)/TbFeCo(7.5nm)复合材料,其稀土元素成分为~26%。

二、性能测试

该TbFeCo(20nm)/Pd(1nm)/TbFeCo(7.5nm)复合材料的磁特性表征如图2所示,结果表明:溅射制备得到的具有7.5nm厚度和20nm厚度的TbFeCo磁性薄膜层的磁特性分别表现为富过渡和富稀土相,其垂直磁化反转场分别为7.6kOe和1.5kOe,差值为6.1kOe。

因此,通过调整该复合材料中两磁性薄膜层的厚度实现不同的富相,两个不同厚度的磁性薄膜层的磁矩方向可以平行或者反平行排列(对应于反常霍尔回线中的4个平台磁状态),利用层间交换耦合作用产生的界面畴壁能扩大两磁性薄膜层磁化反转场的变化差异。

实施例三

一种具有间隔层的稀土-过渡合金复合材料的制备方法,包括以下步骤:

(1)将四片呈等腰三角形的高纯度(纯度为99.95%)的Tb贴片贴在半径为1英寸的高纯度(纯度为99.9%)的铁钴合金靶上,形成溅射用的复合镶嵌靶,各片Tb贴片以铁钴合金靶的圆心为中心点分布在铁钴合金靶上,Tb贴片的顶角为28°,Tb贴片的腰长为2cm,厚度为2mm;

(2)将复合镶嵌靶作为磁控溅射的靶材,安装固定在磁控溅射室的溅射靶座上;

(3)对单晶Si基片依次用丙酮、酒精、异丙醇超声清洗后烘干,将烘干处理后的单晶Si基片安置固定于磁控溅射室的基片台上,调整靶基距为6.5cm;

(4)将溅射真空室抽真空达到真空度为1×10-5Pa,通入高纯度的氩气(纯度为99.999%)作为工作气体,控制氩气的进气流量在60sccm;

(5)调整闸板阀关闭的程度,使溅射工作气压稳定并维持在0.6Pa,先以0.86W/cm2的溅射功率密度对单晶Si基片直流溅射2nm厚度的Ta缓冲层,溅射速率为0.1nm/s,溅射时间为20s,得到具有Ta缓冲层的单晶Si基片,然后对复合镶嵌靶预溅射20min;

(6)调节基片台每分钟旋转10圈,打开基片台和溅射靶座之间的挡板,以5.9W/cm2的溅射功率密度溅射复合镶嵌靶,溅射速率为0.167nm/s,溅射时间为120s,在单晶Si基片上得到20nm厚的稀土-过渡合金薄膜,形成带有第一层稀土-过渡合金薄膜的单晶Si基片;

(7)然后在带有第一层稀土-过渡合金薄膜的单晶Si基片上直流溅射Pd间隔层,溅射速率为0.125nm/s,溅射时间为8s,使得生长的Pd间隔层的厚度为1nm,形成带有间隔层和第一层稀土-过渡合金薄膜的单晶Si基片;

(8)最后在带有间隔层和第一层稀土-过渡合金薄膜的单晶Si基片上继续溅射复合镶嵌靶,溅射速率为0.167nm/s,溅射时间为60s,使得在间隔层上生长的第二层稀土-过渡合金薄膜的厚度为10nm,得到具有间隔层的稀土-过渡合金复合材料;

(9)在得到的稀土-过渡合金复合材料上以0.86W/cm2的溅射功率密度直流溅射2nm厚度的Ta保护层,溅射速率为0.1nm/s,溅射时间为20s,以防止氧化,得到的稀土-过渡合金复合材料记为TbFeCo(20nm)/Pd(1nm)/TbFeCo(10nm)复合材料,其稀土元素成分为~26%。

上述各实施例中的稀土贴片、铁钴合金靶以及单晶Si基片均在市场上购买得到,只需按照纯度要求购买即可。

上述实施例并非限定本发明的产品形态和式样,任何所属技术领域的普通技术人员对其所做的适当变化或修饰,皆应视为不脱离本发明的专利范畴。

【EN】

A kind of preparation method of the rare earth-transition alloy composite materials with wall

Technical field

The invention belongs to magnetic spin electronics and Magnetographic Technology Material Field, refers to a kind of perpendicular magnetic spinning electron

The preparation method of device composite film material, and in particular to be a kind of rare earth-transition alloy composite materials with wall

Preparation method.

Background technology

In recent years, the magnetoelectronic devices such as vertical spin valve and magnetic tunnel-junction are due to device in highdensity advantage and specific surface

Part has the characteristics of more preferable heat endurance and turns into the research and development direction of this area.Wherein, based on vertical magnetic tunnel-junction

Magnetic memory is considered as one of representative technology of high-density nonvolatile memory of future generation.Free layer in vertical magnetic tunnel-junction

Require it is the material with the vertical film surface of easy axle with basic training ergospheres such as reference layers.So find particular easy axis film and its

Simple growth method turns into the key for preparing high density magnetoelectronic devices.

Conventional magneto-optic records rare earth-transition race's alloy firm such as TbFeCo and DyFeCo alloy materials due to big vertical

Magnetic anisotropy and high heat endurance are good, are currently also widely used in high density magnetoelectronic devices field.This ferrimag is thin

Arranged anti-parallel is presented in the magnetic moment of membrane material rare earth elements (Tb or Dy) and transition elements (FeCo) sublattice, causes this kind of

A specific compensation point composition is there may be in material, the coercivity corresponding to this compensation point composition alloy film is unlimited

Greatly.The rare earth-transition alloy firm composition of the vertical film surface of easy axle is normally at a compensation point composition little Composition Region nearby

In domain.The magnetic moment of alloy film material rare earth elements sublattice is more than the magnetic moment then alloy of transition element sublattice during room temperature

Film is Nd-rich phase, on the contrary then be rich transitional face.It is larger that vertical magnetoelectronic devices part requires that rare earth-transition race alloy firm has

The perpendicular coercive force of difference, to meet that free layer in device (coercivity is small, and the direction of magnetization is easily with outer field direction) and pinning layer (are rectified

Stupid power is big, the direction of magnetization be not easy with outer field direction change) etc. difference in functionality layer requirement.Searching has the vertical adverse field of big difference

Rare earth-transition alloy film material preparation method, it is direct in current high density magnetic spin electronics device particularly electric current

The Novel low power consumption information-storing device fields such as induced magnetization reversion are significant, and are possible to produce huge economic effect

Benefit.

The content of the invention

It is an object of the invention to provide a kind of preparation method of the rare earth-transition alloy composite materials with wall,

Preparation technology is simple, and the composite property being prepared is stable, and the structure of the composite is completely simultaneous with vertical magnetoelectronic devices

Hold, can be used for as a kind of new magnetoelectronic devices material in vertical spin valve or magnetic tunnel device.

In order to reach above-mentioned purpose, solution of the invention is:

A kind of preparation method of the rare earth-transition alloy composite materials with wall, comprises the following steps:

(1) using the combined tessera target or ternary alloy three-partalloy target of rare earth paster and ferrocobalt target composition as magnetron sputtering

Target, it is fixed on the sputtering target stand of magnetron sputtering chamber, the rare earth paster is Tb pasters or Dy pasters, the ternary

Alloys target is TbFeCo alloy target or DyFeCo alloys targets, the quantity of the combined tessera target middle rare earth paster and is fixed on

The rare earth-transition alloy that content of rare earth in the position of the sputtering target stand or the ternary alloy three-partalloy target to be prepared is answered

Rare earth elements in condensation material are 25~27.5% (rich rare earths);

(2) by after cleaning, drying substrate placement be fixed on the chip bench of magnetron sputtering chamber, adjustment target-substrate distance be 4~

8cm;

(3) sputtering vacuum chamber is reached into vacuum 1 × 10-5Below Pa, the argon gas for being passed through purity >=99.99% are made

For working gas, the charge flow rate of argon gas is controlled in the range of 30~100sccm;

(4) under conditions of 0.2~1.0Pa of operating air pressure is sputtered, to 10~30min of the target pre-sputtering;

(5) the chip bench circle of rotation 5~15 per minute is adjusted, chip bench is opened and sputters the baffle plate between target stand, with 1.5~

6.5W/cm2Sputtering power density sputter the target, sputter rate be 0.1~0.3nm/s, controls sputtering time to cause

The thick rare earth-transition alloy firms of 20~50nm are obtained on the substrate, are formed with first layer rare earth-transition alloy firm

Substrate;

(6) wall and then on the substrate with first layer rare earth-transition alloy firm is sputtered, when control sputters

Between cause growth the wall thickness in 0.5~2.5nm, formation carries wall and first layer rare earth-transition alloy

The substrate of film, the wall are metal spacing layer or oxide spacers;

(7) finally continue on the substrate with wall and first layer rare earth-transition alloy firm described in sputtering

Target, control sputtering time so that the second layer rare earth-transition alloy firm grown on the wall thickness for 7~

15nm, obtain the rare earth-transition alloy composite materials with wall.

In step (1), the rare earth paster is in the rare earth paster of purity >=99.9% of isosceles triangle, the iron cobalt

Purity >=99.9% of alloys target, each rare earth paster point centered on the center of circle of the ferrocobalt target are attached to the iron

On cobalt alloy target, the combined tessera target of sputtering is formed.

In step (2), the substrate is single crystalline Si substrate or typical commercial band thermal oxide layer single crystalline Si substrate.

In step (4), before target described in pre-sputtering, first splash-proofing sputtering metal cushion or oxide delay on the substrate

Rush layer, control sputtering time causes the thickness of the metal buffer layer or oxide buffer layer to be 0.5~2.5nm, the metal

Cushion is Ta cushions, Ru cushions, Cu cushions, Pd cushions or Pt cushions, and the oxide buffer layer is

SiO2Cushion, MgO cushions or Al2O3Cushion.

In step (6), the metal spacing layer is between Ta walls, Ru walls, Cu walls, Pd walls or Pt

Interlayer, the oxide spacers are SiO2Wall, MgO walls or Al2O3Wall.

In step (6), splashed on the substrate with first layer rare earth-transition alloy firm by direct current or radio frequency

The metal spacing layer is penetrated, passes through oxygen described in radio-frequency sputtering on the substrate with first layer rare earth-transition alloy firm

Compound wall.

In step (7), protected on the obtained rare earth-transition alloy composite materials by direct current or radio-frequency sputtering

Layer, to prevent oxidation, control sputtering time to cause the thickness of the protective layer to be 2~20nm, the protective layer be Ta protective layers,

Ru protective layers, Cu protective layers, Pd protective layers or Pt protective layers.

In Magnetographic Technology Material Field, the magnetic being widely used in the magnetoelectronic devices such as Spin Valve and MTJ is more

Film structure, by nonmagnetic spacer layer produce spin-exchange-coupled effect can make adjacent magnetic layers the intensity of magnetization presentation it is parallel or

The antiparallel arrangement of person, and magnetic state can be maintained stable in the range of a certain size outfield.

A kind of after adopting the above technical scheme, preparation of the rare earth-transition alloy composite materials with wall of the present invention

Method, what is be prepared is the sandwich that a kind of same Ferrimagnetic rare earth-transition alloy with wall is formed,

Mainly it is made up of laminated magnetic film I/ walls/laminated magnetic film II.Adjacent with wall is the magnetic of two different-thickness

Film layer can pass through fixation, it is necessary to by the preparation of same Ferrimagnetic rare earth-transition alloy material (TbFeCo or DyFeCo)

The quantity of target rare earth elements paster and position, or realized using the ternary alloy three-partalloy target of fixed proportion composition.With

The magnetic moment direction of the laminated magnetic film of two adjacent different-thickness of wall can be with parallel or arranged anti-parallel, and can be with

This stable state is maintained in the range of a certain size outfield.By the thickness for adjusting two laminated magnetic films in the composite

Realize different rich phases, using Interlayer Exchange Coupling act on caused by interface wall energy expand two laminated magnetic film magnetization inversion fields

Variation, have big difference magnetization inversion field the rare earth-transition alloy composite materials can be directly used for vertical spin valve

Or in magnetic tunnel device.

A kind of preparation method of the rare earth-transition alloy composite materials with wall of the present invention, there is preparation method letter

The characteristics of single, reproducible and cost is cheap, the composite property that is prepared is stable, the structure of the composite with it is vertical

Magnetoelectronic devices are completely compatible, can be used for vertical spin valve or magnetic tunnel-junction device as a kind of new magnetoelectronic devices material

In part.

Brief description of the drawings

Fig. 1 is the main unusual Hall Curve of TbFeCo (20nm)/Pd (2nm)/TbFeCo (10nm) composite and small

Unusual Hall Curve;

Fig. 2 is the unusual Hall Curve of TbFeCo (20nm)/Pd (1nm)/TbFeCo (7.5nm) composite.

Embodiment

In order to which technical scheme is explained further, the present invention is explained in detail below by specific embodiment

State.

Embodiment one

First, the preparation of composite

A kind of preparation method of the rare earth-transition alloy composite materials with wall, comprises the following steps:

(1) it is 1 inch four Tb pasters in the high-purity (purity 99.95%) of isosceles triangle to be attached into radius

On the ferrocobalt target of high-purity (purity 99.9%), the combined tessera target of sputtering is formed, each Tb paster is closed with iron cobalt

Point is distributed on ferrocobalt target centered on the center of circle of gold target, and the drift angle of Tb pasters is 28 °, a length of 2cm of waist of Tb pasters, thickness

For 2mm;

(2) target using combined tessera target as magnetron sputtering, is fixed on the sputtering target stand of magnetron sputtering chamber;

(3) dried after being cleaned by ultrasonic successively with acetone, alcohol, isopropanol to single crystalline Si substrate, by the list after drying and processing

Brilliant Si substrates placement is fixed on the chip bench of magnetron sputtering chamber, and adjustment target-substrate distance is 6.5cm;

(4) sputtering vacuum chamber is reached into vacuum for 1 × 10-5Pa, being passed through the argon gas of high-purity, (purity is

99.999%) working gas is used as, controls the charge flow rate of argon gas in 60sccm;

(5) degree that slide valve is closed is adjusted, stablizes sputtering operating air pressure and maintains 0.6Pa, first with 1.48W/cm2

Sputtering power density to the MgO cushions of single crystalline Si substrate radio-frequency sputtering 1nm thickness, sputter rate 0.022nm/s, sputtering

Time is 45s, obtains the single crystalline Si substrate with MgO cushions, then to combined tessera target pre-sputtering 20min;

(6) the chip bench circle of rotation 10 per minute is adjusted, chip bench is opened and sputters the baffle plate between target stand, with 5.9W/cm2

Sputtering power density sputtering combined tessera target, sputter rate 0.167nm/s, sputtering time 120s, in single crystalline Si substrate

On obtain the thick rare earth-transition alloy firms of 20nm, form the single crystalline Si substrate with first layer rare earth-transition alloy firm;

(7) the d.c. sputtering Pd walls and then on the single crystalline Si substrate with first layer rare earth-transition alloy firm, splash

Firing rate rate is 0.125nm/s, sputtering time 16s so that the thickness of the Pd walls of growth is 2nm, and formation carries wall

With the single crystalline Si substrate of first layer rare earth-transition alloy firm;

(8) finally sputtering is continued again on the single crystalline Si substrate with wall and first layer rare earth-transition alloy firm

Close mosaic target, sputter rate 0.167nm/s, sputtering time 60s so that the second layer rare earth-mistake grown on wall

The thickness for crossing alloy firm is 10nm, obtains the rare earth-transition alloy composite materials with wall, is designated as TbFeCo

(20nm)/Pd (2nm)/TbFeCo (10nm) composite, its rare earth elements are~26%.

2nd, performance test

The magnetic characteristic of the TbFeCo (20nm)/Pd (2nm)/TbFeCo (10nm) composite is characterized as shown in figure 1, result

Show:The magnetic characteristic for sputtering the TbFeCo laminated magnetic films with 10nm thickness and 20nm thickness being prepared is shown as respectively

Rich transition and Nd-rich phase, its perpendicular magnetization adverse field are respectively 8.5kOe and 2.8kOe, difference 5.7kOe, wherein, pass through

The small unusual Hall go-and-return measurement for only inverting 20nm TbFeCo layers confirms that high level platform is also in main unusual Hall Curve

One stable magnetic state.

Therefore, different rich phases is realized by adjusting the thickness of two laminated magnetic films in the composite, it is two different thick

The magnetic moment direction of the laminated magnetic film of degree can (4 corresponded in main unusual Hall loop line be flat with parallel or arranged anti-parallel

Platform magnetic state), using Interlayer Exchange Coupling act on caused by interface wall energy expand the changes of two laminated magnetic film magnetization inversion fields

Change difference, and this stable magnetic state can be maintained in the range of a certain size outfield.

Embodiment two

First, the preparation of composite

A kind of preparation method of the rare earth-transition alloy composite materials with wall, comprises the following steps:

(1) it is 1 inch four Tb pasters in the high-purity (purity 99.95%) of isosceles triangle to be attached into radius

On the ferrocobalt target of high-purity (purity 99.9%), the combined tessera target of sputtering is formed, each Tb paster is closed with iron cobalt

Point is distributed on ferrocobalt target centered on the center of circle of gold target, and the drift angle of Tb pasters is 28 °, a length of 2cm of waist of Tb pasters, thickness

For 2mm;

(2) target using combined tessera target as magnetron sputtering, is fixed on the sputtering target stand of magnetron sputtering chamber;

(3) to typical commercial band 300nm thermal oxides SiO2The single crystalline Si substrate of layer is surpassed with acetone, alcohol, isopropanol successively

Dried after sound cleaning, the single crystalline Si substrate placement after drying and processing is fixed on the chip bench of magnetron sputtering chamber, adjusts target base

Away from for 6.5cm;

(4) sputtering vacuum chamber is reached into vacuum for 1 × 10-5Pa, being passed through the argon gas of high-purity, (purity is

99.999%) working gas is used as, controls the charge flow rate of argon gas in 60sccm;

(5) degree that slide valve is closed is adjusted, stablizes sputtering operating air pressure and maintains 0.6Pa, to combined tessera target

Pre-sputtering 20min;

(6) the chip bench circle of rotation 10 per minute is adjusted, chip bench is opened and sputters the baffle plate between target stand, with 5.9W/cm2

Sputtering power density sputtering combined tessera target, sputter rate 0.167nm/s, sputtering time 120s, in single crystalline Si substrate

On obtain the thick rare earth-transition alloy firms of 20nm, form the single crystalline Si substrate with first layer rare earth-transition alloy firm;

(7) the radio-frequency sputtering Pd walls and then on the single crystalline Si substrate with first layer rare earth-transition alloy firm, splash

Firing rate rate is 0.125nm/s, sputtering time 8s so that the thickness of the Pd walls of growth is 1nm, formed with wall and

The single crystalline Si substrate of first layer rare earth-transition alloy firm;

(8) finally sputtering is continued again on the single crystalline Si substrate with wall and first layer rare earth-transition alloy firm

Close mosaic target, sputter rate 0.167nm/s, sputtering time 45s so that the second layer rare earth-mistake grown on wall

The thickness for crossing alloy firm is 7.5nm, obtains the rare earth-transition alloy composite materials with wall, is designated as TbFeCo

(20nm)/Pd (1nm)/TbFeCo (7.5nm) composite, its rare earth elements are~26%.

2nd, performance test

The magnetic characteristic of the TbFeCo (20nm)/Pd (1nm)/TbFeCo (7.5nm) composite characterizes as shown in Fig. 2 knot

Fruit shows:Sputter the magnetic characteristic difference table for the TbFeCo laminated magnetic films with 7.5nm thickness and 20nm thickness being prepared

It is now rich transition and Nd-rich phase, its perpendicular magnetization adverse field is respectively 7.6kOe and 1.5kOe, difference 6.1kOe.

Therefore, different rich phases is realized by adjusting the thickness of two laminated magnetic films in the composite, it is two different thick

The magnetic moment direction of the laminated magnetic film of degree can be with parallel or arranged anti-parallel (4 platforms corresponded in unusual Hall loop line

Magnetic state), using Interlayer Exchange Coupling act on caused by interface wall energy expand the changes of two laminated magnetic film magnetization inversion fields

Difference.

Embodiment three

A kind of preparation method of the rare earth-transition alloy composite materials with wall, comprises the following steps:

(1) it is 1 inch four Tb pasters in the high-purity (purity 99.95%) of isosceles triangle to be attached into radius

On the ferrocobalt target of high-purity (purity 99.9%), the combined tessera target of sputtering is formed, each Tb paster is closed with iron cobalt

Point is distributed on ferrocobalt target centered on the center of circle of gold target, and the drift angle of Tb pasters is 28 °, a length of 2cm of waist of Tb pasters, thickness

For 2mm;

(2) target using combined tessera target as magnetron sputtering, is fixed on the sputtering target stand of magnetron sputtering chamber;

(3) dried after being cleaned by ultrasonic successively with acetone, alcohol, isopropanol to single crystalline Si substrate, by the list after drying and processing

Brilliant Si substrates placement is fixed on the chip bench of magnetron sputtering chamber, and adjustment target-substrate distance is 6.5cm;

(4) sputtering vacuum chamber is reached into vacuum for 1 × 10-5Pa, being passed through the argon gas of high-purity, (purity is

99.999%) working gas is used as, controls the charge flow rate of argon gas in 60sccm;

(5) degree that slide valve is closed is adjusted, stablizes sputtering operating air pressure and maintains 0.6Pa, first with 0.86W/cm2

Sputtering power density to the Ta cushions of single crystalline Si substrate d.c. sputtering 2nm thickness, sputter rate 0.1nm/s, during sputtering

Between be 20s, the single crystalline Si substrate with Ta cushions is obtained, then to combined tessera target pre-sputtering 20min;

(6) the chip bench circle of rotation 10 per minute is adjusted, chip bench is opened and sputters the baffle plate between target stand, with 5.9W/cm2

Sputtering power density sputtering combined tessera target, sputter rate 0.167nm/s, sputtering time 120s, in single crystalline Si substrate

On obtain the thick rare earth-transition alloy firms of 20nm, form the single crystalline Si substrate with first layer rare earth-transition alloy firm;

(7) the d.c. sputtering Pd walls and then on the single crystalline Si substrate with first layer rare earth-transition alloy firm, splash

Firing rate rate is 0.125nm/s, sputtering time 8s so that the thickness of the Pd walls of growth is 1nm, formed with wall and

The single crystalline Si substrate of first layer rare earth-transition alloy firm;

(8) finally sputtering is continued again on the single crystalline Si substrate with wall and first layer rare earth-transition alloy firm

Close mosaic target, sputter rate 0.167nm/s, sputtering time 60s so that the second layer rare earth-mistake grown on wall

The thickness for crossing alloy firm is 10nm, obtains the rare earth-transition alloy composite materials with wall;

(9) with 0.86W/cm on obtained rare earth-transition alloy composite materials2Sputtering power density d.c. sputtering

The Ta protective layers of 2nm thickness, sputter rate 0.1nm/s, sputtering time 20s, to prevent oxidation, obtained rare earth-transition

Alloy composite materials are designated as TbFeCo (20nm)/Pd (1nm)/TbFeCo (10nm) composite, its rare earth elements for~

26%.

Rare earth paster, ferrocobalt target and single crystalline Si substrate in the various embodiments described above are commercially commercially available,

It need to only be bought according to purity requirement.

Above-described embodiment and non-limiting product form of the invention and style, the ordinary skill people of any art

The appropriate change or modification that member is done to it, it all should be regarded as not departing from the patent category of the present invention.

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