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一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法 【EN】Process method for preparing single-phase high manganese silicon film under raw material oxidation condition

申请(专利)号:CN202110390892.0国省代码:贵州 52
申请(专利权)人:【中文】贵州大学【EN】Guizhou University
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摘要:
【中文】本发明公开了一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法:以含有MnO的Mn靶材作为原料,在Si衬底上通过磁控溅射的方法制备薄膜,构成“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构样品,进而在真空条件下高温退火。基于该工艺办法,通过控制“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构中的Si薄膜中间层溅射时间,可以完全消除掉本来含量占比很大的MnO,获得单一相的高锰硅薄膜材料,显著降低了获得高锰硅薄膜对原料、储存及工艺条件的要求,使得高锰硅薄膜的制备更为简单,产业化生产成本降低,生产效率得到提高。 【EN】The invention discloses a process method for preparing a single-phase high manganese-silicon film under the condition of raw material oxidation, which comprises the following steps: mn target material containing MnO is used as raw material, a film is prepared on a Si substrate by a magnetron sputtering method, and a three-layer structure sample of the Si substrate, the Si film and the Mn film containing oxide is formed, and then high-temperature annealing is carried out under a vacuum condition. Based on the process method, by controlling the sputtering time of the Si film middle layer in the three-layer structure of the Si substrate, the Si film and the Mn film containing oxides, MnO with large content ratio can be completely eliminated, the high manganese silicon film material with a single phase is obtained, the requirements of the obtained high manganese silicon film on raw materials, storage and process conditions are obviously reduced, the preparation of the high manganese silicon film is simpler, the industrial production cost is reduced, and the production efficiency is improved.

主权项:
【中文】1.一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法,其特征在于,包括以下步骤: 步骤一,将洗净的Si衬底安装到高真空磁控溅射系统的样品架上固定,作为用于镀膜的基片,在仪器内的射频溅射靶位和直流溅射靶位上分别安装Si靶材、Mn靶材; 步骤二,充入Ar气介质:将高真空磁控溅射系统的腔体进行抽真空,当本底真空度优于5×10Pa后,从通气口持续通入气流量为40sccm的高纯Ar气,使腔体内气压达到2.0Pa并保持稳定; 步骤三,在Si衬底上沉积Si膜:移开挡在Si靶材上的靶材挡板,再启动该靶位的射频溅射电源,射频溅射电源射频匹配成功后Si靶材溅射起辉,预溅射一段时间后移开遮挡Si衬底的样品挡板,使得Si靶材溅射出的Si单质在Si衬底上沉积形成Si薄膜,镀膜完成后操作样品挡板挡住镀有Si薄膜的Si衬底,并关闭Si靶位的射频溅射电源,之后移动Si靶位的靶材挡板将Si靶材挡住; 步骤四,在镀有Si薄膜的Si衬底上沉积Mn膜:移开挡住Mn靶材的靶材挡板并启动该靶位的直流溅射电源,Mn靶材溅射起辉,预溅射一段时间后将挡住Si衬底的样品挡板移开,使得Mn靶材上的物质沉积到Si薄膜表面形成Mn薄膜,构成“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构样品,溅射完成后用样品挡板挡住样品,之后关闭直流溅射电源,用Mn靶位的靶材挡板挡住Mn靶材; 步骤五,退火:将经过上述步骤获得到的三层结构样品放置于真空退火炉内,抽至本底真空度优于5×10Pa后,开启加热电源开始对三层结构样品进行加热,升温至700℃恒温一段时间,而后随炉冷却到常温,可去除掉Mn膜中含有的MnO,并获得到单一相的高锰硅薄膜。 【EN】1. A process method for preparing a single-phase high manganese silicon film under the condition of raw material oxidation is characterized by comprising the following steps: mounting a cleaned Si substrate on a sample rack of a high-vacuum magnetron sputtering system for fixing, and respectively mounting a Si target and a Mn target on a radio-frequency sputtering target position and a direct-current sputtering target position in an instrument as substrates for coating; step two, filling Ar gas medium: vacuumizing the cavity of the high-vacuum magnetron sputtering system when the background vacuum degree is better than 5 multiplied by 10After Pa, continuously introducing high-purity Ar gas with the gas flow of 40sccm from the vent hole to ensure that the air pressure in the cavity reaches 2.0Pa and keeps stable; depositing a Si film on the Si substrate: removing a target baffle plate blocked on the Si target, starting a radio frequency sputtering power supply of the target, sputtering and glowing the Si target after the radio frequency sputtering power supply is successfully matched with the radio frequency, removing a sample baffle plate for blocking the Si substrate after pre-sputtering for a period of time, depositing Si simple substance sputtered from the Si target on the Si substrate to form a Si film, operating the sample baffle plate to block the Si substrate plated with the Si film after film coating is finished, closing the radio frequency sputtering power supply of the Si target, and then moving the target baffle plate of the Si target to block the Si target; step four, depositing a Mn film on the Si substrate plated with the Si film: moving a target baffle for blocking the Mn target material away and starting a direct current sputtering power supply of the target position, sputtering the Mn target material to glow, moving a sample baffle for blocking the Si substrate away after pre-sputtering for a period of time so that substances on the Mn target material are deposited on the surface of the Si film to form a Mn film, forming a three-layer structure sample of the Si substrate, the Si film and the Mn film containing oxides, blocking the sample by the sample baffle after sputtering is finished, then closing the direct current sputtering power supply, and blocking the Mn target material by the target baffle of the Mn target position; step five, annealing: will be obtained through the stepsThe obtained three-layer structure sample is placed in a vacuum annealing furnace and is pumped until the background vacuum degree is superior to 5 multiplied by 10And after Pa, starting a heating power supply to heat the three-layer structure sample, heating to 700 ℃, keeping the temperature constant for a period of time, cooling to the normal temperature along with the furnace, removing MnO contained in the Mn film, and obtaining the single-phase high manganese silicon film.


说明书

【中文】

一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法

技术领域

本发明涉及一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法,属于高锰硅半导体制备工艺技术领域。

背景技术

高锰硅是一种环境友好型半导体材料,具备多种优点,在热电和光电领域具有很大的应用潜力,可以用来构建红外探测器、光电继电器、光电二极管和光敏电阻器等实用器件;常用的高锰硅薄膜制备工艺是通过磁控溅射等方式在硅衬底上镀一层锰薄膜,之后在真空条件下进行高温热处理,就可以制备出高锰硅薄膜;

磁控溅射是制备均匀薄膜的常用方式,它的基本原理是:使用高能离子轰击靶材表面,使靶材表面的物质被溅射起来,通过磁场对粒子运动方向加以限制,最终附着在衬底表面;该方式需要用到磁控溅射靶材,这里需要用到的主要是锰金属靶材;Mn(锰)是一种活跃的金属,在空气中容易氧化,在普通设备条件下,无法避免原料与空气接触,这就会使反应原料中含有锰的氧化物,在短期氧化的情况下,氧化物主要为MnO;集成有手套箱的设备成本很高,且会进一步提高占地,由于真空腔体的容积增加,抽真空所需的时间也会显著增加;

Mn提纯难度大,想要制备成磁控溅射用的靶材则工艺难度会进一步增加。对比市场上的各种靶材,其它金属常用的纯度为4N(99.99%),而Mn在国内市场上能够买到的最高纯度仅为3N5(99.95%),大部分厂商只能提供3N(99.9%)及以下纯度产品,且大量厂商生产出的产品会由于工艺及储存问题而伴随有氧化物存在,也主要为MnO;

在原料中含有MnO存在的时候,使用常规高锰硅制备工艺制备出的产物中会存在大量的MnO,这会显著影响产物的纯度,进而影响以此材料构建的半导体器件性能;

因此,在原料纯度难以达到要求,工艺对仪器条件要求苛刻的情况下,如何解决制备高锰硅过程中MnO的存在问题显得极为重要。

发明内容

为解决上述技术问题,本发明提供了一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法。

本发明通过以下技术方案得以实现。

本发明提供的一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法,包括步骤如下:

步骤一,将洗净的Si衬底安装到高真空磁控溅射系统的样品架上固定,作为用于镀膜的基片,在仪器内的射频溅射靶位和直流溅射靶位上分别安装Si靶材、Mn靶材;

步骤二,充入Ar气介质:将高真空磁控溅射系统的腔体进行抽真空,当本底真空度优于5×10-4Pa后,从通气口持续通入气流量为40sccm的高纯Ar气,使腔体内气压达到2.0Pa并保持稳定;

步骤三,在Si衬底上沉积Si膜:移开挡在Si靶材上的靶材挡板,再启动该靶位的射频溅射电源,射频溅射电源射频匹配成功后Si靶材溅射起辉,预溅射一段时间后移开遮挡Si衬底的样品挡板,使得Si靶材溅射出的Si单质在Si衬底上沉积形成Si薄膜,镀膜完成后操作样品挡板挡住镀有Si薄膜的Si衬底,并关闭Si靶位的射频溅射电源,之后移动Si靶位的靶材挡板将Si靶材挡住;

步骤四,在镀有Si薄膜的Si衬底上沉积Mn膜:移开挡住Mn靶材的靶材挡板并启动该靶位的直流溅射电源,Mn靶材溅射起辉,预溅射一段时间后将挡住Si衬底的样品挡板移开,使得Mn靶材上的物质沉积到Si薄膜表面形成Mn薄膜,构成“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构样品,溅射完成后用样品挡板挡住样品,之后关闭直流溅射电源,用Mn靶位的靶材挡板挡住Mn靶材;

步骤五,退火:将经过上述步骤获得到的三层结构样品放置于真空退火炉内,抽至本底真空度优于5×10-4Pa后,开启加热电源开始对三层结构样品进行加热,升温至700℃恒温一段时间,而后随炉冷却到常温,可去除掉Mn膜中含有的MnO,并获得到单一相的高锰硅薄膜。

在所述步骤一中,Si靶材为纯度5N及以上;Mn靶材标称为纯度3N及以上,但是存在大量自然氧化物MnO。

在所述步骤三中,所述射频溅射功率为80W,Si膜的沉积时间为35min,该参数在Mn薄膜的溅射参数及MnO含量发生改变时需要作出调整。

在所述步骤四中,由于Mn靶材含有氧化物MnO,使用该靶材溅射得到的Mn薄膜中也会含有的MnO存在。

在所述步骤四中,所述直流溅射功率为110W,Mn薄膜沉积时间为5min。

在所述步骤四中,通过在“Si衬底—含有氧化物的Mn薄膜”两层结构中间加入Si薄膜作为中间层的方法,形成“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构样品。

在所述步骤五中,对“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构样品以12℃/min的升温速率进行升温,加热至700℃后恒温4h,而后停止加热,让样品在真空条件下随炉冷却到常温。

本发明的有益效果主要在于:

(1)对原料及实验仪器的要求不再苛刻。在原来情况下,原料一旦氧化,就需要弃用,而本工艺可以将这种废弃的原料用来制备出单一的原目标产物——高锰硅。

(2)现有技术一直认为高锰硅一定需要由Mn单质与Si单质之间的反应得到,而本方案的基本物理思想是MnO会与Si发生反应产生高锰硅,为高锰硅的制备工艺加入了新的反应途径。

(3)增加了对Si原子分布密度这一参数的考虑。通过改变“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构中的Si薄膜中间层的厚度,可以对反应速率及用于反应的Si原子数量进行调控。

附图说明

图1是在未加入Si中间层时制得材料的XRD图谱;

图2是本文实施例得到材料的XRD图谱;

图3是控制不同Si中间层溅射时间得到材料的XRD图谱。

具体实施方式

为了更为清晰地描述本发明的技术方案,用一实施例,并结合附图,对本发明方案作进一步具体的说明,但要求保护的范围并不局限于所述。

本发明的一种在原料氧化情况下制备单一相高锰硅薄膜的工艺方法,包括步骤如下:

步骤一,安装基片和靶材:将晶向为<100>的高阻Si衬底样品在丙酮、无水乙醇、去离子水中各依次超声清洗20min,目的是除去表面杂质,将洗净的Si衬底安装到高真空磁控溅射系统的样品架上固定,作为用于镀膜的基片,在仪器内的射频溅射靶位和直流溅射靶位上分别安装Si靶材、Mn靶材;Si靶材为纯度5N及以上;Mn靶材标称为纯度3N及以上,但是存在大量自然氧化物MnO;

步骤二,充入Ar气介质:将高真空磁控溅射系统的腔体进行抽真空,当本底真空度至少达到5×10-4Pa后,从通气口持续通入气流量为40sccm的高纯Ar气,使腔体内气压达到2.0Pa并保持稳定;

步骤三,在Si衬底上沉积Si膜:移开挡在Si靶材上的靶材挡板,再启动该靶位的射频溅射电源,射频溅射电源射频匹配成功后Si靶材溅射起辉,预溅射30min后移开遮挡Si衬底样品的样品挡板,使得Si靶材溅射出的Si原子在Si衬底上沉积形成Si薄膜,溅射功率为80w,镀膜时间为35min,镀膜完成后操作样品挡板挡住镀有Si薄膜的Si衬底,并关闭Si靶位的射频溅射电源,之后移动Si靶位的靶材挡板将Si靶材挡住;

步骤四,在镀有Si薄膜的Si衬底上沉积Mn膜:移开挡住Mn靶材的靶材挡板并启动高真空磁控溅射系统的直流溅射电源,Mn靶材溅射起辉,预溅射30min后将挡住Si衬底的样品挡板移开,使得Mn靶材上的原子沉积到Si薄膜表面形成Mn薄膜,溅射功率为110w,溅射时间为5min,由于Mn靶材含有氧化物MnO,使用其溅射得到的Mn薄膜中也会含有与其同比例的MnO存在,构成“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构样品,溅射完成后用样品挡板挡住样品,之后关闭直流溅射电源,用Mn靶位的靶材挡板挡住Mn靶材;

步骤五,退火:将腔体抽至本底真空度优于5×10-4Pa后,开启高真空磁控溅射系统的原位加热电源,使用样品架内置的加热盘对“Si衬底—Si薄膜—含有氧化物的Mn薄膜”三层结构样品进行加热,升温速率12℃/min,升温至700℃后恒温4h,而后保持真空条件,使样品随炉冷却到常温,可去除掉Mn膜中含有的MnO,并获得到单一相的高锰硅薄膜,如图2所示。

本发明中,通过加入Si中间层来解决原料氧化问题的基本原理在于MnO会与Si发生反应,在本工艺条件下可反应得到高锰硅。另外,Si原子分布密度也对反应过程起到了显著的影响。可以注意到,Mn薄膜原本反应的对象是Si衬底,而本发明引入的Si中间层的物质组成与Si衬底其实是一样的,均为Si单质。其主要区别就在于Si中间层与Si衬底的密度不同:磁控溅射得到的Si中间层密度较小,而Si衬底则是由熔炼方式制备出的,其密度显著大于Si中间层的密度。这导致Si中间层由于密度较低,原子分布松散,更容易与Mn薄膜之间发生互相渗透,相当于Si与Mn的混合物之间进行反应;而Si衬底由于密度很高,原子分布过于紧密,难以与Mn薄膜之间发生互相渗透,导致反应主要发生于Mn薄膜与Si衬底的交界处。由于生成的物质相对较为稳定,因此难以进一步发生反应,产物会堆积于交界处。又因为Si衬底的Si原子密度高,所生成物质的密度也是较高的。会在交界处形成高密度的隔离层,阻碍Mn薄膜与Si衬底之间反应的进行。

通过加入Si中间层的方法,则可以让Si衬底与表面薄膜界面处的反应相对缓和。Mn薄膜会先与Si中间层之间发生渗透并发生反应,Si衬底则会在Si原子不够时向薄膜提供足够的Si原子,随着Si中间层厚度的增加,Si衬底的影响会降低。通过改变Si中间层的厚度,可以对反应速率及用于反应的Si原子数量进行调控。

在所述步骤三中,作为优选的,所述高真空磁控溅射系统的射频溅射功率为80W,Si膜的沉积时间为35min,从图3中可知,当沉积时间为大于0小于等于25min时,MnO峰逐渐减小,高锰硅中的MnO含量减低,同时高锰硅含量增加;当沉积时间为35min时,MnO峰几乎完全消失,高锰硅中的MnO含量最低;当沉积时间到45min后,MnO峰又出现增加,高锰硅中的MnO含量增加。这表明Si中间层的溅射时间并不是越长越好,而是存在一个恰当值,本实施例中该恰当值为35min。在Mn薄膜的溅射参数及MnO含量发生改变时,Si中间层的溅射参数需要作出调整。

图1是在未加入Si中间层时制得材料的XRD图谱。

根据图1可知,在未加入Si中间层时,如果作为原料的Mn靶材未氧化时,可以得到Mn27Si47单一相产物,Mn27Si47是高锰硅的一个典型物相;而在Mn靶材中含有氧化物MnO时,则产物中会含有显著的MnO存在,其峰值甚至比目标产物Mn27Si47还要高,因此,原料的氧化会显著影响产物的纯度。

图2是本文发明技术的实施例得到材料的XRD图谱。

除加入Si中间层外,原料与工艺均与图1中Mn靶材中含有氧化物MnO时情况一致,相比图1中原料氧化时的结果,通过本实施例得到的结果如图2所示。可以看到,通过本实施例可以得到单一相的高锰硅,而将MnO几乎完全消除掉,证明本方案可以很好地起到消除氧化物的作用,且产物唯一。

图3是控制不同Si中间层溅射时间得到材料的XRD图谱。

为了进一步证明加入Si中间层的作用,以Si中间层的溅射时间作为变量,将获得到材料的XRD图谱之间进行对比,结果如图3所示。可以看到,加入Si中间层后MnO峰值显著降低,而高锰硅的主峰峰值显著增加,呈现择优取向,当Si中间层溅射沉积时间达到35min时,MnO峰几乎完全消失,同时高锰硅的各峰位的峰值分布均匀,与标准图图谱一致。但Si中间层溅射时间进一步增加到45min时,MnO峰重新出现,高锰硅的多处峰值出现降低。

【EN】

Process method for preparing single-phase high manganese silicon film under raw material oxidation condition

Technical Field

The invention relates to a process method for preparing a single-phase high manganese-silicon film under the condition of raw material oxidation, belonging to the technical field of high manganese-silicon semiconductor preparation processes.

Background

The high manganese silicon is an environment-friendly semiconductor material, has multiple advantages, has great application potential in the thermoelectric and photoelectric fields, and can be used for constructing practical devices such as infrared detectors, photoelectric relays, photodiodes, photoresistors and the like; the common preparation process of the high manganese silicon film is to plate a layer of manganese film on a silicon substrate by means of magnetron sputtering and the like, and then to carry out high-temperature heat treatment under the vacuum condition, so as to prepare the high manganese silicon film;

magnetron sputtering is a common way to prepare uniform thin films, and the basic principle is as follows: bombarding the surface of the target material by using high-energy ions, so that substances on the surface of the target material are sputtered, and limiting the movement direction of particles by a magnetic field to finally attach to the surface of the substrate; the method needs to use a magnetron sputtering target material, wherein the manganese metal target material is mainly used; mn (manganese) is an active metal and is easily oxidized in air, and under the condition of common equipment, the raw materials cannot be prevented from contacting with air, so that the reaction raw materials contain manganese oxide, and under the condition of short-term oxidation, the oxide is mainly MnO; the equipment integrated with the glove box has high cost, the occupied area can be further improved, and the time required for vacuumizing can be obviously increased due to the increase of the volume of the vacuum cavity;

the difficulty of Mn purification is high, and the process difficulty is further increased when the Mn is prepared into the target material for magnetron sputtering. Compared with various targets on the market, the purity of other metals is 4N (99.99%), the highest purity of Mn available in domestic markets is only 3N5 (99.95%), most manufacturers can only provide products with the purity of 3N (99.9%) or less, and products produced by a large number of manufacturers are accompanied by oxide due to process and storage problems and mainly comprise MnO;

when MnO exists in the raw materials, a large amount of MnO exists in the product prepared by using the conventional high manganese silicon preparation process, so that the purity of the product is obviously influenced, and the performance of a semiconductor device constructed by the material is further influenced;

therefore, under the conditions that the purity of the raw materials is difficult to meet the requirement and the process has strict requirements on instrument conditions, how to solve the problem of MnO in the process of preparing high manganese silicon is very important.

Disclosure of Invention

In order to solve the technical problems, the invention provides a process method for preparing a single-phase high manganese silicon film under the condition of raw material oxidation.

The invention is realized by the following technical scheme.

The invention provides a process method for preparing a single-phase high manganese silicon film under the condition of raw material oxidation, which comprises the following steps:

mounting a cleaned Si substrate on a sample rack of a high-vacuum magnetron sputtering system for fixing, and respectively mounting a Si target and a Mn target on a radio-frequency sputtering target position and a direct-current sputtering target position in an instrument as substrates for coating;

step two, filling Ar gas medium: vacuumizing the cavity of the high-vacuum magnetron sputtering system when the background vacuum degree is better than 5 multiplied by 10-4After Pa, continuously introducing high-purity Ar gas with the gas flow of 40sccm from the vent hole to ensure that the air pressure in the cavity reaches 2.0Pa and keeps stable;

depositing a Si film on the Si substrate: removing a target baffle plate blocked on the Si target, starting a radio frequency sputtering power supply of the target, sputtering and glowing the Si target after the radio frequency sputtering power supply is successfully matched with the radio frequency, removing a sample baffle plate for blocking the Si substrate after pre-sputtering for a period of time, depositing Si simple substance sputtered from the Si target on the Si substrate to form a Si film, operating the sample baffle plate to block the Si substrate plated with the Si film after film coating is finished, closing the radio frequency sputtering power supply of the Si target, and then moving the target baffle plate of the Si target to block the Si target;

step four, depositing a Mn film on the Si substrate plated with the Si film: moving a target baffle for blocking the Mn target material away and starting a direct current sputtering power supply of the target position, sputtering the Mn target material to glow, moving a sample baffle for blocking the Si substrate away after pre-sputtering for a period of time so that substances on the Mn target material are deposited on the surface of the Si film to form a Mn film, forming a three-layer structure sample of the Si substrate, the Si film and the Mn film containing oxides, blocking the sample by the sample baffle after sputtering is finished, then closing the direct current sputtering power supply, and blocking the Mn target material by the target baffle of the Mn target position;

step five, annealing: placing the three-layer structure sample obtained by the steps in a vacuum annealing furnace, and pumping until the background vacuum degree is superior to 5 multiplied by 10-4And after Pa, starting a heating power supply to heat the three-layer structure sample, heating to 700 ℃, keeping the temperature constant for a period of time, cooling to the normal temperature along with the furnace, removing MnO contained in the Mn film, and obtaining the single-phase high manganese silicon film.

In the first step, the purity of the Si target is 5N or more; mn targets are nominally 3N and above pure, but there is a significant amount of native oxide MnO.

In the third step, the radio frequency sputtering power is 80W, the deposition time of the Si film is 35min, and the parameters need to be adjusted when the sputtering parameters of the Mn film and the MnO content are changed.

In the fourth step, since the Mn target contains oxide MnO, MnO which may be contained in the Mn thin film obtained by sputtering using the target is also present.

In the fourth step, the direct current sputtering power is 110W, and the deposition time of the Mn thin film is 5 min.

In the fourth step, a sample of a three-layer structure of "Si substrate-Si thin film-Mn thin film containing oxide" was formed by adding a Si thin film as an intermediate layer between the two-layer structure of "Si substrate-Mn thin film containing oxide".

In the fifth step, the three-layer structure sample of the Si substrate-Si film-Mn film containing oxide is heated at the heating rate of 12 ℃/min, the temperature is kept for 4h after the sample is heated to 700 ℃, then the heating is stopped, and the sample is cooled to the normal temperature along with the furnace under the vacuum condition.

The invention has the following beneficial effects:

(1) the requirements for raw materials and experimental instruments are not strict any more. In the original situation, the raw material needs to be discarded once being oxidized, and the discarded raw material can be used for preparing a single original target product, namely high manganese silicon.

(2) The prior art always considers that the high manganese silicon is obtained by the reaction between a simple substance Mn and a simple substance Si, and the basic physical idea of the scheme is that MnO can react with Si to generate the high manganese silicon, so that a new reaction path is added to the preparation process of the high manganese silicon.

(3) The consideration of this parameter of the distribution density of Si atoms is increased. The reaction rate and the number of Si atoms used for reaction can be regulated and controlled by changing the thickness of the Si film intermediate layer in the three-layer structure of the Si substrate, the Si film and the Mn film containing the oxide.

Drawings

FIG. 1 is an XRD pattern of the material produced without the addition of an intermediate layer of Si;

FIG. 2 is an XRD pattern of the material obtained in the examples herein;

FIG. 3 is an XRD pattern of the material obtained by controlling the sputtering time of different Si intermediate layers.

Detailed Description

To more clearly describe the technical solution of the present invention, the embodiment is further specifically described with reference to the accompanying drawings, but the scope of the claimed invention is not limited to the description.

The invention relates to a process method for preparing a single-phase high manganese silicon film under the condition of raw material oxidation, which comprises the following steps:

step one, mounting a substrate and a target material: sequentially ultrasonically cleaning a high-resistance Si substrate sample with a crystal orientation of <100> in acetone, absolute ethyl alcohol and deionized water for 20min respectively to remove surface impurities, mounting the cleaned Si substrate on a sample rack of a high-vacuum magnetron sputtering system for fixing as a substrate for coating, and respectively mounting a Si target and a Mn target on a radio-frequency sputtering target and a direct-current sputtering target in an instrument; the Si target has a purity of 5N or more; mn targets are nominally 3N and above pure, but there is a significant amount of native oxide MnO;

step two, filling Ar gas medium: vacuumizing the cavity of the high-vacuum magnetron sputtering system until the background vacuum degree reaches at least 5 multiplied by 10-4After Pa, continuously introducing high-purity Ar gas with the gas flow of 40sccm from the vent hole to ensure that the air pressure in the cavity reaches 2.0Pa and keeps stable;

depositing a Si film on the Si substrate: removing a target baffle plate blocked on the Si target, starting a radio frequency sputtering power supply of the target position, sputtering and glowing the Si target after the radio frequency sputtering power supply is successfully matched in radio frequency, moving a sample baffle plate for blocking the Si substrate sample after pre-sputtering for 30min, so that Si atoms sputtered from the Si target deposit on the Si substrate to form a Si film, wherein the sputtering power is 80w, the film coating time is 35min, operating the sample baffle plate to block the Si substrate plated with the Si film after the film coating is finished, closing the radio frequency sputtering power supply of the Si target position, and then moving the target baffle plate of the Si target position to block the Si target;

step four, depositing a Mn film on the Si substrate plated with the Si film: removing a target baffle for blocking the Mn target material, starting a direct-current sputtering power supply of a high-vacuum magnetron sputtering system, sputtering the Mn target material to glow, removing a sample baffle for blocking the Si substrate after pre-sputtering for 30min, so that atoms on the Mn target material are deposited on the surface of the Si film to form the Mn film, wherein the sputtering power is 110w, the sputtering time is 5min, and because the Mn target material contains oxide MnO, the Mn film obtained by sputtering the Mn target material also contains MnO in the same proportion as the MnO, so that a three-layer structure sample of 'Si substrate-Si film-Mn film containing oxide' is formed, after the sputtering is finished, blocking the sample by using the sample baffle, then closing the direct-current sputtering power supply, and blocking the Mn target material by using the target baffle of Mn target position;

step five, annealing: pumping the cavity to background vacuum degree superior to 5 × 10-4After Pa, starting an in-situ heating power supply of the high-vacuum magnetron sputtering system, heating a three-layer structure sample of a Si substrate, a Si film and an oxide-containing Mn film by using a heating plate arranged in a sample rack, wherein the heating rate is 12 ℃/min, the temperature is kept constant for 4h after the temperature is raised to 700 ℃, and then the vacuum condition is kept to ensure that the sample is subjected to vacuum treatmentWhen the temperature is cooled to normal temperature along with the furnace, MnO contained in the Mn film can be removed, and a single-phase high manganese silicon film is obtained, as shown in figure 2.

In the invention, the basic principle of solving the problem of raw material oxidation by adding the Si intermediate layer is that MnO reacts with Si, and high manganese silicon can be obtained by reaction under the process condition. In addition, the distribution density of Si atoms also has a significant influence on the reaction process. It can be noted that the original reaction object of the Mn thin film is the Si substrate, and the material composition of the Si intermediate layer introduced in the present invention is substantially the same as that of the Si substrate, and is a Si simple substance. The main difference is that the density of the Si intermediate layer is different from that of the Si substrate: the Si intermediate layer obtained by magnetron sputtering has low density, and the Si substrate is prepared by smelting, and the density of the Si intermediate layer is obviously higher than that of the Si intermediate layer. This results in a lower density of the Si intermediate layer, a loose atomic distribution, and a greater tendency to interpenetrate with the Mn film, which is equivalent to a reaction between the mixture of Si and Mn; the Si substrate has high density and too tight atomic distribution, so that the Si substrate is difficult to mutually permeate with the Mn film, and the reaction mainly occurs at the junction of the Mn film and the Si substrate. Since the resulting material is relatively stable, further reaction is difficult and the product accumulates at the interface. Further, since the Si atom density of the Si substrate is high, the density of the generated substance is also high. A high-density spacer layer is formed at the interface, which hinders the reaction between the Mn thin film and the Si substrate.

By the method of adding the Si intermediate layer, the reaction at the interface of the Si substrate and the surface thin film can be relatively moderated. The Mn film firstly permeates and reacts with the Si intermediate layer, the Si substrate provides enough Si atoms for the film when the Si atoms are insufficient, and the influence of the Si substrate is reduced along with the increase of the thickness of the Si intermediate layer. By changing the thickness of the Si intermediate layer, the reaction rate and the number of Si atoms used for the reaction can be regulated.

In the third step, preferably, the radio frequency sputtering power of the high vacuum magnetron sputtering system is 80W, the deposition time of the Si film is 35min, and as can be seen from fig. 3, when the deposition time is more than 0 and less than or equal to 25min, the MnO peak gradually decreases, the MnO content in the high manganese silicon decreases, and the high manganese silicon content increases; when the deposition time is 35min, the MnO peak almost completely disappears, and the MnO content in the high manganese silicon is lowest; when the deposition time reaches 45min, the MnO peak is increased again, and the MnO content in the high manganese silicon is increased. This indicates that the sputtering time of the Si interlayer is not as long as possible but there is a proper value, which is 35min in this embodiment. When the sputtering parameters of the Mn film and the MnO content are changed, the sputtering parameters of the Si intermediate layer need to be adjusted.

Figure 1 is an XRD pattern of the material prepared without the addition of an Si interlayer.

As is clear from FIG. 1, when the Si intermediate layer is not added, Mn can be obtained if the Mn target material as the raw material is not oxidized27Si47Single phase product, Mn27Si47Is a typical phase of high manganese silicon; when the Mn target material contains oxide MnO, the product can contain remarkable MnO, and the peak value of the MnO is even more than that of the target product Mn27Si47Yet high, and therefore, oxidation of the feedstock can significantly affect the purity of the product.

Figure 2 is an XRD pattern of the material obtained by an example of the inventive technique herein.

The raw materials and the process were the same as those in the case of the Mn target material containing the oxide MnO in fig. 1 except that the Si intermediate layer was added, and the results obtained by this example are shown in fig. 2, compared with the results in fig. 1 when the raw material was oxidized. It can be seen that a single phase of high manganese silicon can be obtained by this example, and MnO is almost completely eliminated, which proves that this scheme can well perform the function of eliminating oxides and the product is unique.

FIG. 3 is an XRD pattern of the material obtained by controlling the sputtering time of different Si intermediate layers.

To further demonstrate the effect of adding the Si interlayer, XRD patterns of the obtained materials were compared with each other with sputtering time of the Si interlayer as a variable, and the results are shown in fig. 3. It can be seen that the MnO peak is obviously reduced after the Si intermediate layer is added, the main peak of the high manganese silicon is obviously increased, preferred orientation is presented, when the sputtering deposition time of the Si intermediate layer reaches 35min, the MnO peak almost completely disappears, and simultaneously, the peak values of all peak positions of the high manganese silicon are uniformly distributed and are consistent with the standard map. However, when the sputtering time of the Si intermediate layer was further increased to 45min, the MnO peak reappeared and the peak values of the high manganese silicon were reduced.

图1
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