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一种用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料及其制备方法 【EN】Zr-doped Ge2Sb2Te5 thin-film material for phase change memory and preparation method of Zr-doped Ge2Sb2Te5 thin-film material

申请(专利)号:CN201610119008.9国省代码:浙江 33
申请(专利权)人:【中文】宁波大学【EN】Ningbo University
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摘要:
【中文】本发明公开了一种用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料及其制备方法,特点是其化学结构式为Zrx(Ge2Sb2Te5)100‑x,其中0<x<20,其制备方法具体步骤如下:采用高纯度圆块状Zr单质与Ge2Sb2Te5作为靶材,采用磁控溅射装置,采用双靶共溅射方法,以高纯氩气作为工作气体,采用石英片或硅片为衬底材料进行表面沉积,将Zr单质靶的直流溅射功率调整为3~9W,Ge2Sb2Te5靶的射频溅射功率调整为60W,于室温下共溅射15min后,得到Zr掺杂Ge2Sb2Te5薄膜材料,优点是具有较高的结晶温度和数据保持力,较快的结晶速度,较大的非晶态/晶态电阻比以及较好的热稳定性。 【EN】Paragraph:The invention discloses a Zr-doped Ge2Sb2Te5 thin-film material for a phase change memory and a preparation method of the Zr-doped Ge2Sb2Te5 thin-film material. The Zr-doped Ge2Sb2Te5 thin-film material is characterized in that a chemical structural formula is Zrx(Ge2Sb2Te5)(100-x), wherein x is smaller than to 20 and greater than to 0. The preparation method comprises the following specific steps: adopting a high-purity round block Zr element and Ge2Sb2Te5 as target materials, with high-purity argon as a working gas and a quartz plate or a silicon wafer as a substrate material, carrying out surface deposition by a magnetron sputtering apparatus and a double-target co-sputtering method; adjusting the DC sputtering power of the Zr element target to be 3-9W and the radio-frequency sputtering power of the Ge2Sb2Te5 target to be 60W; and carrying out co-sputtering at a room temperature for 15 minutes and then obtaining the Zr-doped Ge2Sb2Te5 thin-film material. The Zr-doped Ge2Sb2Te5 thin-film material has the advantages of relatively high crystallization temperature and data retentivity, relatively high crystallization speed, relatively high amorphous/crystalline resistance ratio and relatively good heat stability.Image:201610119008.GIF

主权项:
【中文】1.一种用于相变存储器的Zr掺杂GeSbTe薄膜材料,其特征在于:其化学结构式为Zr(GeSbTe),其中0


说明书

【中文】

一种用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料及其制备方法

技术领域

本发明涉及相变存储材料领域,尤其是涉及一种用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料及其制备方法。

背景技术

随着计算机技术、移动通信和数码产品的快速发展,对非易失性半导体存储器的需求显著增加。目前非易失存储器市场的主流是闪存,然而闪存自身存在的一些不足,如较长的写入时间(>10μs)和较低的循环次数(~106),使其很难满足未来半导体存储器发展对更高擦写速度和存储密度的要求,另外由于存储电荷的基本要求,浮栅不能无限制的减薄,突破45 nm半导体制程存在很大的技术困难。PCRAM日益引起科学界和业界的关注,不仅仅因为其满足非易失性存储器的各种要求,还因为其制造工艺相对简单。基于硫系化合物的PCRAM被广认为是最具前景的非易失存储器之一,有可能在市场上取代Flash成为下一代非易失存储器,因为PCRAM有近乎完美的性能,例如微缩性好、数据保持力强、成本低及与CMOS工艺兼容性好等特点。此外,PCRAM存储技术具有抗强震动、抗辐射性能,在航天航空领域具有极其重要的应用前景。

PCRAM的综合性能主要取决于存储介质的相变特性。在所有的相变硫系化合物中,Ge2Sb2Te5(GST)是应用在PCRAM中最常用的材料。然而,较高的熔点和较低的晶态电阻率使得GST不可避免地出现较高的RESET电流和功耗。另外在汽车电子等领域对数据保持力有特殊要求:数据在120℃的环境下能保持10年。传统GST材料因为其结晶温度低,热稳性不佳,以GST材料为存储介质的PRAM 存储单元的数据只能够在80℃左右保存10年,高温下的数据保存寿命短,所以GST不能满足此要求。为优化PCRAM的性能,通常在GST中掺杂其他元素,来提高相变材料晶态电阻率,降低RESET电流以及提高数据保持力,使掺杂后GST材料应用于相变存储器中成为可能。

发明内容

本发明所要解决的技术问题是提供一种具有较高的结晶温度和数据保持力,较快的结晶速度,较大的非晶态/晶态电阻比以及较好的热稳定性的用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料及其制备方法,该方法成本低,工艺可控性强,易于大规模生产。

本发明解决上述技术问题所采用的技术方案为:一种用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料,其化学结构式为Zrx(Ge2Sb2Te5)100-x,其中0<x<20。

所述的相变薄膜材料的结晶温度为150-300℃。

所述的相变薄膜材料的非晶电阻在106~108Ω,晶态电阻103~104Ω。

所述的薄膜材料的化学结构式为Zr12(Ge2Sb2Te5)88。该相变薄膜材料的数据保持力能够在120.9℃下保存十年。

上述用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料的制备方法,采用高纯度圆块状Zr单质与Ge2Sb2Te5作为靶材,采用磁控溅射装置,采用双靶共溅射方法,以高纯氩气作为工作气体,采用石英片或硅片为衬底材料进行表面沉积,具体步骤如下:

(1)将Ge2Sb2Te5圆块状玻璃靶材和Zr单质靶材背面,完全贴合一块与玻璃靶材直径相同,厚度为1mm的铜片,制得磁控溅射镀膜靶材;将Zr单质靶材安装在磁控直流直流溅射靶中,将Ge2Sb2Te5靶材安装在磁控射频溅射靶中;

(2)将石英片或硅片衬底材料放入去离子水中,超声清洗20分钟,然后放入无水乙醇中超声清洗20分钟,取出后用高纯氮气吹干,放入溅射腔室;

(3)将磁控溅射室进行抽真空,直至溅射室内真空度达到2×10-4Pa时,向室内通入高纯氩气,氩气流量为50ml/min,直至溅射腔室内气压达到溅射所需的起辉气压0.3Pa;

(4)开启射频电源,待辉光稳定后,将Zr单质靶的直流溅射功率调整为3~9W,Ge2Sb2Te5靶的射频溅射功率调整为60W,于室温下进行溅射镀膜,共溅射15min后,得到用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料。

所述的Zr靶材和所述Ge2Sb2Te5靶材的纯度均为99.99%。

将步骤(4)步骤得到的沉积态的Zr掺杂Ge2Sb2Te5薄膜材料放入快速退火炉中,在高纯氩气氛围保护下,迅速升温至200~350℃下进行退火,即得到热处理后的Zr掺杂GST相变存储薄膜材料。

与现有技术相比,本发明的优点在于:本发明一种用于相变存储器的Zr掺杂GST薄膜材料及其制备方法,其化学式结构为Zrx(Ge2Sb2Te5)100-x,其中0<x<20,该薄膜的结晶温度为165~200℃,数据保存10年的最高温度为84.4~120.9℃;测试结果表明,随着Zr掺杂含量的增加,样品的晶态电阻也在增加,有利于降低PRAM的功耗。本发明具有工艺可控性强,生产成本低,重复性好,制备得到的Zr掺杂GST薄膜材料不仅具有组分偏差小、附着强度高、膜质均匀致密的优点,而且具有较高的结晶温度,较快的结晶速度,较大的非晶态/晶态电阻比以及较好的热稳定性,可以用于工业化规模制备大面积的相变薄膜,从而满足未来相变存储材料的应用需求。

附图说明

图1为不同组分的Zrx(GST)100-x薄膜方块电阻随温度变化关系曲线;

图2为不同组分的Zrx(GST)100-x薄膜的数据保持力计算结果图;

图3为组分Zr9(GST)91的薄膜样品在不同温度下退火后的X射线衍射图谱;

图4为不同组分的Zrx(GST)100-x薄膜在250℃下退火后的X射线衍射图谱;

图5为不同组分的Zrx(GST)100-x薄膜在300℃下退火后的X射线衍射图谱;

图6为不同组分的Zrx(GST)100-x薄膜在350℃下退火后的X射线衍射图谱。

具体实施方式

以下结合附图实施例对本发明作进一步详细描述。

一、具体实施例

一种用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料,其化学结构式为Zrx(Ge2Sb2Te5)100-x,其中0<x<20,该薄膜材料的结晶温度为150-300℃,非晶电阻在106~108Ω,晶态电阻103~104Ω。其制备方法如下:采用高纯度圆块状Zr单质与Ge2Sb2Te5作为靶材,采用磁控溅射装置,采用双靶共溅射方法,以高纯氩气作为工作气体,采用石英片或硅片为衬底材料进行表面沉积,具体步骤如下:

(1)将Ge2Sb2Te5圆块状玻璃靶材和Zr单质靶材背面,完全贴合一块与玻璃靶材直径相同,厚度为1mm的铜片,制得磁控溅射镀膜靶材;将Zr单质靶材安装在磁控直流直流溅射靶中,将Ge2Sb2Te5靶材安装在磁控射频溅射靶中;

(2)将石英片或硅片衬底材料放入去离子水中,超声清洗20分钟,然后放入无水乙醇中超声清洗20分钟,取出后用高纯氮气吹干,放入溅射腔室;

(3)将磁控溅射室进行抽真空,直至溅射室内真空度达到2×10-4Pa时,向室内通入高纯氩气,氩气流量为50ml/min,直至溅射腔室内气压达到溅射所需的起辉气压0.3Pa;

(4)开启射频电源,待辉光稳定后,将Zr单质靶的直流溅射功率调整为3~9W,Ge2Sb2Te5靶的射频溅射功率调整为60W,于室温下进行溅射镀膜,共溅射15min后,得到用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料。

上述得到的沉积态的Zr掺杂Ge2Sb2Te5薄膜材料放入快速退火炉中,在高纯氩气氛围保护下,迅速升温至200~350℃下进行退火,即得到热处理后的Zr掺杂GST相变存储薄膜材料。

上述所用的磁控溅射装置由中国科学院沈阳科学仪器研制中心有限公司制造的JGP-450磁控溅射沉积系统。采用的溅射靶材均为纯度99.99%,尺寸Φ50×3mm。在圆块状Ge2Sb2Te5与Zr单质背面粘贴1mm厚的直径相同的铜片,以解决玻璃靶材在溅射过程中散热问题。

实施例1

一种用于相变存储器的Zr掺杂Ge2Sb2Te5薄膜材料,其制备方法如下:

(1)采用Ge2Sb2Te5和Zr单质双靶共溅射镀膜:将Zr单质靶材安装在磁控直流直流溅射靶中,将Ge2Sb2Te5靶材安装在磁控射频溅射靶中;对溅射腔室进行抽真空处理,当溅射腔室内真空度达到2×10­­-4Pa时,向室内充入高纯氩气,氩气流量为50.0ml/min,直至腔室内达到溅射所需的起辉气压0.3Pa;开启射频电源,待辉光稳定后,调节Zr单质所在的直流溅射靶功率为3W,Ge2Sb2Te5靶材所在磁控射频溅射功率为60W,待功率稳定后,开启衬底转盘自转并将自转速率设定为5rpm,打开衬底下方的挡板,溅射15分钟后得到沉积态的Zr掺杂GST薄膜;

(2)将步骤(1)得到的沉积态的相变存储薄膜样品放入快速退火炉中,在高纯氮气氛围的保护下,迅速升温到200~350℃下进行退火,得到热处理后的Zr掺杂Ge2Sb2Te5薄膜材料。退火期间通入高纯氮气的作用是为避免薄膜在高温下发生氧化。

上述实施例1制备得到的Zr掺杂Ge2Sb2Te5薄膜组分由X射线能谱分析法(EDS)测得,薄膜厚度由台阶仪测得,测试结果为:薄膜组分为Zr4(GST)96,薄膜厚度为210nm。

实施例2

同实施例1,其区别点在于,调节Zr单质所在的直流溅射靶功率为5W,Ge2Sb2Te5靶材所在磁控射频溅射功率为60W。

上述实施例1制备得到的Zr掺杂Ge2Sb2Te5薄膜组分由X射线能谱分析法(EDS)测得,薄膜厚度由台阶仪测得,测试结果为:薄膜组分为Zr6(GST)94,薄膜厚度为235nm。

实施例3

同实施例1,其区别点在于,调节Zr单质所在的直流溅射靶功率为7W,Ge2Sb2Te5靶材所在磁控射频溅射功率为60W。

上述实施例1制备得到的Zr掺杂Ge2Sb2Te5薄膜组分由X射线能谱分析法(EDS)测得,薄膜厚度由台阶仪测得,测试结果为:薄膜组分为Zr9(GST)91,薄膜厚度为260nm。

实施例4

同实施例1,其区别点在于,调节Zr单质所在的直流溅射靶功率为9W,Ge2Sb2Te5靶材所在磁控射频溅射功率为60W。

上述实施例1制备得到的Zr掺杂Ge2Sb2Te5薄膜组分由X射线能谱分析法(EDS)测得,薄膜厚度由台阶仪测得,测试结果为:薄膜组分为Zr12(GST)88,薄膜厚度为290nm。

二、实验结果分析

对上述实施例制备的Zrx(GST)100-x薄膜进行性能测试,图1和图2为原位电阻性能测试结果。图1为不同组分的薄膜在10℃/min升温速率下方块电阻与温度的关系。由于薄膜的电阻在结晶温度(Tc)处急剧下降,从图1中可以看出,组分为Zr4(GST)96的薄膜具有两次结晶现象,随着Zr含量的增加,两次结晶现象被抑制,材料的结晶温度也明显升高,材料的热稳定性得到提高,进而可以提高相变存储器的数据保持力,这也在图2中得到证实。由图2可知,随着Zr含量的增加,材料10年数据保持力也不断提高。

图3为组分Zr9(GST)91的薄膜样品在不同温度下退火后的X射线衍射图。由图可知,在150℃退火后的X射线衍射图呈现宽的大包络,没出现析晶峰,说明分Zr9(GST)91薄膜样品在该温度下为非晶态;当温度高于200℃时,出现了明显的析晶峰,这表明该组分的薄膜样品的析晶温度在150℃到200℃之间,该结果与图1相符。

图4,图5和图6是不同组分的Zrx(GST)100-x薄膜分别在250℃,300℃和350℃下退火后的X射线衍射图谱。实施例1制备的薄膜从非晶态到多晶态的相变是一个两步的结晶过程,即首先从非晶态变化到亚稳态面心立方结构(fcc),然后从fcc继续变化到六方密堆结构(hex)。从图6中可以看到,在350℃温度下退火3min后,Zrx(GST)100-x薄膜各个组分都有晶体析出。并且随着Zr含量的增加,析晶峰的强度有明显的减弱,这说明Zr的掺杂抑制了GST的析晶,从而提高了Zrx(GST)100-x薄膜的结晶温度,使得材料的热稳定性大大改善。

上述说明并非对本发明的限制,本发明也并不限于上述举例。本技术领域的普通技术人员在本发明的实质范围内,作出的变化、改型、添加或替换,也应属于本发明的保护范围,本发明的保护范围以权利要求书为准。

【EN】

A kind of Zr doping Ge for phase transition storage2Sb2Te5Thin-film material and preparation method thereof

Technical field

The present invention relates to phase-change storage material field, especially relate to a kind of Zr doping Ge for phase transition storage2Sb2Te5Thin-film material and preparation method thereof.

Background technology

Along with the fast development of computer technology, mobile communication and digital product, the demand of nonvolatile semiconductor memory is dramatically increased.At present the main flow in nonvolatile storage market is flash memory, but the some shortcomings that flash memory self exists, write time (> 10 μ s as longer) and relatively low cycle-index (~ 106) so that it is being difficult to meet future semiconductor memorizer and develop the highest erasable speed and the requirement of memory density, additionally, due to the basic demand of storage electric charge, floating boom can not be unconfined thinning, breaks through 45 nm manufacture of semiconductor and there is the biggest technical difficulty.PCRAM causes the concern of scientific circles and industry day by day, not only because it meets the various requirement of nonvolatile memory, also as its manufacturing process is relatively easy.PCRAM based on chalcogenide compound is by one of nonvolatile storage being extensively considered most prospect, the most commercially replace Flash and become nonvolatile storage of future generation, because PCRAM has, the performance of almost Perfect, such as micro be good, data retention is strong, low cost and with the feature such as CMOS technology compatibility is good.Additionally, PCRAM memory technology has anti-strong motion, radiation resistance, in field of aerospace, there is extremely important application prospect.

The combination property of PCRAM depends primarily on the phase-change characteristic of storage medium.In all of phase transformation chalcogenide compound, Ge2Sb2Te5(GST) it is to apply material the most frequently used in PCRAM.But, higher fusing point and relatively low crystalline resistance rate make GST higher RESET electric current and power consumption inevitably occur.Additionally in fields such as automotive electronics, data retention is had particular/special requirement: data can keep 10 years in the environment of 120 DEG C.Conventional GST material is because its crystallization temperature is low, and thermostability is the best, and the data of the PRAM memory element with GST material as storage medium are merely able to preserve 10 years at about 80 DEG C, and it is short, so GST can not meet this requirement that the data under high temperature preserve the life-span.For optimizing the performance of PCRAM, generally adulterate in GST other elements, improves phase-change material crystalline resistance rate, reduces RESET electric current and improves data retention, and after making doping, GST materials application is possibly realized in phase transition storage.

Summary of the invention

The technical problem to be solved is to provide a kind of Zr doping Ge for phase transition storage with higher crystallization temperature and data retention, faster crystallization rate, bigger amorphous state/crystalline resistance ratio and preferable heat stability2Sb2Te5Thin-film material and preparation method thereof, the method low cost, process controllability is strong, it is easy to large-scale production.

The present invention solves the technical scheme that above-mentioned technical problem used: a kind of Zr for phase transition storage adulterates Ge2Sb2Te5Thin-film material, its chemical structural formula is Zrx(Ge2Sb2Te5)100-x, wherein 0 < x < 20.

The crystallization temperature of described phase change film material is 150-300 DEG C.

The amorphous resistance of described phase change film material is 106~108Ω, crystalline resistance 103~104Ω。

The chemical structural formula of described thin-film material is Zr12(Ge2Sb2Te5)88.The data retention of this phase change film material can preserve 10 years at 120.9 DEG C.

The above-mentioned Zr doping Ge for phase transition storage2Sb2Te5The preparation method of thin-film material, uses high-purity nahlock shape Zr simple substance and Ge2Sb2Te5As target, using magnetic control sputtering device, use double target co-sputtering method, using high-purity argon gas as working gas, using piezoid or silicon chip is that backing material carries out surface deposition, specifically comprises the following steps that

(1) by Ge2Sb2Te5Nahlock shape glass target and the Zr simple substance target back side, completely laminating one piece are identical with glass target diameter, and thickness is the copper sheet of 1mm, prepare magnetron sputtering plating target;Zr simple substance target is arranged in magnetic control DC sputtering target, by Ge2Sb2Te5Target is arranged in magnetron RF sputtering system target;

(2) piezoid or silicon chip substrate material are put in deionized water, ultrasonic cleaning 20 minutes, it is then placed in ultrasonic cleaning 20 minutes in dehydrated alcohol, dries up with high pure nitrogen after taking-up, put into sputtering chamber;

(3) magnetron sputtering chamber is carried out evacuation, until vacuum reaches 2 × 10 in sputtering chamber-4During Pa, being passed through high-purity argon gas to indoor, argon flow amount is 50ml/min, until sputtering chamber internal gas pressure reaches to sputter required build-up of luminance air pressure 0.3Pa;

(4) open radio-frequency power supply, after aura is stable, the d.c. sputtering power of Zr simple substance target is adjusted to 3 ~ 9W, Ge2Sb2Te5The radio-frequency sputtering power of target is adjusted to 60W, carries out sputter coating at room temperature, after cosputtering 15min, obtains the Zr doping Ge for phase transition storage2Sb2Te5Thin-film material.

Described Zr target and described Ge2Sb2Te5The purity of target is 99.99%.

The Zr doping Ge of the deposited that step (4) step is obtained2Sb2Te5Thin-film material is put in quick anneal oven, under high-purity argon gas atmosphere is protected, is brought rapidly up annealing at 200 ~ 350 DEG C, i.e. obtains the doping GST phase transiting storing thin-film material of the Zr after heat treatment.

Compared with prior art, it is an advantage of the current invention that: a kind of Zr doping GST thin-film material for phase transition storage of the present invention and preparation method thereof, its chemical formula structure is Zrx(Ge2Sb2Te5)100-x, wherein 0 < x < 20, the crystallization temperature of this thin film is 165 ~ 200 DEG C, and it is 84.4 ~ 120.9 DEG C that data preserve the maximum temperature of 10 years;Test result shows, along with the increase of Zr doping content, the crystalline resistance of sample is also increasing, and advantageously reduces the power consumption of PRAM.It is strong that the present invention has process controllability, production cost is low, reproducible, the Zr doping GST thin-film material prepared not only has that component deviation is little, adhesive strength is high, the advantage of film quality even compact, and there is higher crystallization temperature, faster crystallization rate, bigger amorphous state/crystalline resistance ratio and preferably heat stability, may be used for industrially scalable and prepare large-area phase-change thin film, thus meet the application demand of following phase-change storage material.

Accompanying drawing explanation

Fig. 1 is the Zr of different componentx(GST)100-xFilm rectangular resistance varies with temperature relation curve;

Fig. 2 is the Zr of different componentx(GST)100-xThe data retention result of calculation figure of thin film;

Fig. 3 is component Zr9(GST)91Film sample anneal at different temperatures after X ray diffracting spectrum;

Fig. 4 is the Zr of different componentx(GST)100-xThin film anneal at 250 DEG C after X ray diffracting spectrum;

Fig. 5 is the Zr of different componentx(GST)100-xThin film anneal at 300 DEG C after X ray diffracting spectrum;

Fig. 6 is the Zr of different componentx(GST)100-xThin film anneal at 350 DEG C after X ray diffracting spectrum.

Detailed description of the invention

Below in conjunction with accompanying drawing embodiment, the present invention is described in further detail.

One, specific embodiment

A kind of Zr doping Ge for phase transition storage2Sb2Te5Thin-film material, its chemical structural formula is Zrx(Ge2Sb2Te5)100-x, wherein 0 < x < 20, the crystallization temperature of this thin-film material is 150-300 DEG C, and amorphous resistance is 106~108Ω, crystalline resistance 103~104Ω.Its preparation method is as follows: use high-purity nahlock shape Zr simple substance and Ge2Sb2Te5As target, using magnetic control sputtering device, use double target co-sputtering method, using high-purity argon gas as working gas, using piezoid or silicon chip is that backing material carries out surface deposition, specifically comprises the following steps that

(1) by Ge2Sb2Te5Nahlock shape glass target and the Zr simple substance target back side, completely laminating one piece are identical with glass target diameter, and thickness is the copper sheet of 1mm, prepare magnetron sputtering plating target;Zr simple substance target is arranged in magnetic control DC sputtering target, by Ge2Sb2Te5Target is arranged in magnetron RF sputtering system target;

(2) piezoid or silicon chip substrate material are put in deionized water, ultrasonic cleaning 20 minutes, it is then placed in ultrasonic cleaning 20 minutes in dehydrated alcohol, dries up with high pure nitrogen after taking-up, put into sputtering chamber;

(3) magnetron sputtering chamber is carried out evacuation, until vacuum reaches 2 × 10 in sputtering chamber-4During Pa, being passed through high-purity argon gas to indoor, argon flow amount is 50ml/min, until sputtering chamber internal gas pressure reaches to sputter required build-up of luminance air pressure 0.3Pa;

(4) open radio-frequency power supply, after aura is stable, the d.c. sputtering power of Zr simple substance target is adjusted to 3 ~ 9W, Ge2Sb2Te5The radio-frequency sputtering power of target is adjusted to 60W, carries out sputter coating at room temperature, after cosputtering 15min, obtains the Zr doping Ge for phase transition storage2Sb2Te5Thin-film material.

The Zr doping Ge of deposited obtained above2Sb2Te5Thin-film material is put in quick anneal oven, under high-purity argon gas atmosphere is protected, is brought rapidly up annealing at 200 ~ 350 DEG C, i.e. obtains the doping GST phase transiting storing thin-film material of the Zr after heat treatment.

The JGP-450 magnetron sputtering deposition system that above-mentioned magnetic control sputtering device used is manufactured by Shenyang Scientific Instrument Research & Mfg. Center Co., Ltd., C.A.S.The sputtering target material used is purity 99.99%, size Φ 50 × 3mm.At nahlock shape Ge2Sb2Te5The copper sheet that diameter thick for 1mm is identical is pasted, to solve glass target heat dissipation problem in sputter procedure with the Zr simple substance back side.

Embodiment 1

A kind of Zr doping Ge for phase transition storage2Sb2Te5Thin-film material, its preparation method is as follows:

(1) Ge is used2Sb2Te5With Zr simple substance double target co-sputtering plated film: Zr simple substance target is arranged in magnetic control DC sputtering target, by Ge2Sb2Te5Target is arranged in magnetron RF sputtering system target;Sputtering chamber is carried out evacuation process, when in sputtering chamber, vacuum reaches 2 × 10­­-4During Pa, being filled with high-purity argon gas to indoor, argon flow amount is 50.0ml/min, until reaching in chamber to sputter required build-up of luminance air pressure 0.3Pa;Opening radio-frequency power supply, after aura is stable, the d.c. sputtering target power output at regulation Zr simple substance place is 3W, Ge2Sb2Te5Target place magnetron RF sputtering system power is 60W, after power stability, opens substrate rotating disk rotation and autorotation speed is set as 5rpm, opening the baffle plate below substrate, obtains the Zr doping GST thin film of deposited after sputtering 15 minutes;

(2) the phase change memory film sample of deposited step (1) obtained is put in quick anneal oven, under the protection of high pure nitrogen atmosphere, is brought rapidly up at 200 ~ 350 DEG C annealing, and obtains the doping Ge of the Zr after heat treatment2Sb2Te5Thin-film material.The effect being passed through high pure nitrogen during annealing is for avoiding thin film at high temperature to aoxidize.

The Zr doping Ge that above-described embodiment 1 prepares2Sb2Te5Film composition is recorded by X-ray energy spectrum analytic process (EDS), and film thickness is recorded by step instrument, and test result is: film composition is Zr4(GST)96, film thickness is 210nm.

Embodiment 2

With embodiment 1, its distinctive points is, the d.c. sputtering target power output at regulation Zr simple substance place is 5W, Ge2Sb2Te5Target place magnetron RF sputtering system power is 60W.

The Zr doping Ge that above-described embodiment 1 prepares2Sb2Te5Film composition is recorded by X-ray energy spectrum analytic process (EDS), and film thickness is recorded by step instrument, and test result is: film composition is Zr6(GST)94, film thickness is 235nm.

Embodiment 3

With embodiment 1, its distinctive points is, the d.c. sputtering target power output at regulation Zr simple substance place is 7W, Ge2Sb2Te5Target place magnetron RF sputtering system power is 60W.

The Zr doping Ge that above-described embodiment 1 prepares2Sb2Te5Film composition is recorded by X-ray energy spectrum analytic process (EDS), and film thickness is recorded by step instrument, and test result is: film composition is Zr9(GST)91, film thickness is 260nm.

Embodiment 4

With embodiment 1, its distinctive points is, the d.c. sputtering target power output at regulation Zr simple substance place is 9W, Ge2Sb2Te5Target place magnetron RF sputtering system power is 60W.

The Zr doping Ge that above-described embodiment 1 prepares2Sb2Te5Film composition is recorded by X-ray energy spectrum analytic process (EDS), and film thickness is recorded by step instrument, and test result is: film composition is Zr12(GST)88, film thickness is 290nm.

Two, interpretation

Zr prepared by above-described embodimentx(GST)100-xThin film carries out performance test, Fig. 1 and Fig. 2 is In-situ resistance the performance test results.Fig. 1 is that the thin film of different component is at 10 DEG C/Min heating rate lower block resistance and the relation of temperature.Owing to the resistance of thin film drastically declines at crystallization temperature (Tc) place, from figure 1 it appears that component is Zr4(GST)96Thin film there is twice crystalline polamer, along with the increase of Zr content, twice crystalline polamer is suppressed, the crystallization temperature of material is the most significantly raised, the heat stability of material is improved, and then can improve the data retention of phase transition storage, and this is confirmed the most in fig. 2.As shown in Figure 2, along with the increase of Zr content, material 10 annual data retentivity also improves constantly.

Fig. 3 is component Zr9(GST)91Film sample anneal at different temperatures after X-ray diffractogram.As seen from the figure, the X-ray diffractogram after 150 DEG C of annealing presents wide big envelope, crystallize peak does not occurs, a point Zr is described9(GST)91Film sample is amorphous state at such a temperature;When temperature is higher than 200 DEG C, occur in that obvious crystallize peak, this show the recrystallization temperature of film sample of this component between 150 DEG C to 200 DEG C, this result is consistent with Fig. 1.

Fig. 4, Fig. 5 and Fig. 6 are the Zr of different componentx(GST)100-xThe thin film X ray diffracting spectrum respectively at 250 DEG C, after annealing at 300 DEG C and 350 DEG C.The phase transformation from amorphous state to polycrystalline state of the thin film of embodiment 1 preparation is the crystallization process of two steps, first changes to metastable state face-centred cubic structure (fcc) from amorphous state, then continues to change to the close pile structure of six side (hex) from fcc.It will be seen from figure 6 that anneal at a temperature of 350 DEG C after 3min, Zrx(GST)100-xEach component of thin film has crystal to separate out.And along with the increase of Zr content, the intensity at crystallize peak has and significantly weakens, the doping of this explanation Zr inhibits the crystallize of GST, thus improves Zrx(GST)100-xThe crystallization temperature of thin film so that the heat stability of material is substantially improved.

Described above not limitation of the present invention, the present invention is also not limited to the example above.Those skilled in the art, in the essential scope of the present invention, the change made, retrofit, add or replace, and also should belong to protection scope of the present invention, and protection scope of the present invention is as the criterion with claims.

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