CN107513695A - 利用Nb掺杂调谐Ga2O3禁带宽度的方法 - Google Patents

利用Nb掺杂调谐Ga2O3禁带宽度的方法 Download PDF

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CN107513695A
CN107513695A CN201710741284.3A CN201710741284A CN107513695A CN 107513695 A CN107513695 A CN 107513695A CN 201710741284 A CN201710741284 A CN 201710741284A CN 107513695 A CN107513695 A CN 107513695A
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邓金祥
张�浩
潘志伟
白志英
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    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
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    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
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Abstract

利用Nb掺杂调谐Ga2O3禁带宽度的方法，属于半导体材料领域。使用射频磁控溅射设备在单晶抛光硅片(Si)上沉积一层Nb:Ga2O3薄膜材料。用一种管式炉慢退火的杂质激活工艺，使Nb:Ga2O3薄膜材料中Nb分布均匀化；使Nb离子迁移到晶格中的空位缺陷处，并由间隙位占据替代位；减少结构缺陷，提高结晶化程度，增大晶粒尺寸，进一步提高薄膜质量。与已有技术相比，本发明的特征在于通过选用Nb作为掺杂剂，Ga2O3的禁带宽度有更大的禁带宽度调谐范围。

Description

利用Nb掺杂调谐Ga2O3禁带宽度的方法
技术领域
本发明涉及三种利用Nb掺杂调谐Ga2O3禁带宽度的方法，属于半导体材料领域。
背景技术
Ga2O3是一种宽禁带半导体材料，其禁带宽度Eg＝4.9eV，是目前所知的禁带最宽的透明导电材料。Ga2O3较大的禁带宽度，使其具有高的击穿电压，高的饱和电子漂移速率，热导率大和化学性质稳定等特点，因而Ga2O3在更短波长范围内工作的新一代光电器件中有着广泛的应用前景，如深紫外探测器，短波发光器件，透明电子器件等。
Ga2O3薄膜的禁带宽度决定了其光电器件对应的工作光波波长。单一的禁带宽度势必会限制Ga2O3在光电子器件领域的应用范围。为了拓展Ga2O3在光电器件中的应用领域，扩展其对应的工作光波的波长范围，大量科研者通过掺杂技术对Ga2O3薄膜在光学和电学的性能进行了改进。
目前，众多科研小组已经对Mg、Si、Mn、Eu、Pr、Nd、Sn等元素的掺入对Ga2O3薄膜带隙的影响进行了研究报道。Mn、Eu、Pr、Nd、Sn等元素的氧化物禁带间距都要比Ga2O3的小，在Ga2O3薄膜中掺入Mn、Eu、Pr、Nd、Sn等离子后，薄膜的禁带宽度均低于本征Ga2O3薄膜的禁带宽度。MgO的禁带宽度为7.8eV，SiO2的禁带宽度为8.9eV，这两者的禁带宽度均比Ga2O3的禁带宽度大。在Ga2O3薄膜中掺入Mg、Si等离子后，薄膜的禁带宽度均高于本征Ga2O3薄膜的禁带宽度。现有技术只能在高于或低于本征Ga2O3薄膜的禁带宽度方向进行禁带调谐。
综上所述，亟需一种对Ga2O3薄膜禁带宽度进行更大范围调谐的方法：既能获得高于本征Ga2O3薄膜的禁带宽度，又能获得低于本征Ga2O3薄膜的禁带宽度的禁带调谐的方法。
发明内容
本发明采用Nb作为掺杂剂，通过改变Nb:Ga2O3薄膜中Nb掺杂浓度，控制Nb:Ga2O3薄膜退火环境，改变Nb:Ga2O3薄膜厚度三种方法，既能制备低于本征Ga2O3禁带宽度的Nb:Ga2O3材料，又能制备高于本征Ga2O3禁带宽度的Nb:Ga2O3材料，实现了对Ga2O3材料禁带宽度更大的调谐范围。
本发明的目的可通过如下技术流程实现：
(1)使用射频磁控溅射设备在单晶抛光硅片(Si)上沉积一层Nb:Ga2O3薄膜材料。
Nb:Ga2O3薄膜的生长方式有两种：Nb靶材和Ga2O3靶材共溅射，获得掺杂均匀的Nb:Ga2O3薄膜材料；Nb靶材和Ga2O3靶材交替溅射，在衬底上分层生长Nb:Ga2O3薄膜材料。
(2)本发明采用一种管式炉慢退火的杂质激活工艺。目的是：使Nb:Ga2O3薄膜材料中Nb分布均匀化；使Nb离子迁移到晶格中的空位缺陷处，并由间隙位占据替代位；减少结构缺陷，提高结晶化程度，增大晶粒尺寸，进一步提高薄膜质量。
本发明提供的慢退火温度为1000℃；恒温时间60-240min内可调。慢速退火保护气体可使用高纯Ar、N2或O2(纯度99.999％)。通入保护气体后，开始升温，整个退火过程持续通气。
进一步，共溅射或者交替溅射得到的薄膜材料厚度为100-300nm。
进一步，共溅射得到的薄膜材料Nb掺杂质量百分比含量为0.8％-3％。
与已有技术相比，本发明的特征在于通过选用Nb作为掺杂剂，Ga2O3的禁带宽度有更大的禁带宽度调谐范围。
附图说明
图1为Ga2O3和Nb2O5薄膜交替沉积示意图：(1)Ga2O3沉积层(2)Nb2O5沉积层(3)Si衬底
图2为实施例1所获得薄膜的禁带宽度变化(Nb掺杂浓度对Nb:Ga2O3薄膜禁带的影响)
图3为实施例2所获得薄膜的禁带宽度变化(退火环境对Nb:Ga2O3薄膜禁带的影响)
图4为实施例3所获得薄膜的禁带宽度变化(薄膜厚度对Nb:Ga2O3薄膜禁带的影响)
具体实施方式
用以下实例进一步介绍本发明。
实施例1
(1)采用抛光的n型硅片作为衬底(电阻率2～4Ωcm，厚度为0.3mm)。将衬底分别用甲苯、丙酮、乙醇和去离子水各自超声清洗15min后放入手套箱干燥1小时。
(2)利用射频磁控溅射设备以分层生长的方式沉积Nb:Ga2O3薄膜材料，通过控制Nb2O5和Ga2O3靶材的溅射时间控制Nb的掺杂剂量。系统预真空度在1×10-3Pa以下。薄膜的生长气氛为Ar，工作气压为0.5Pa。Ga2O3和Nb2O5靶材的溅射功率均为80W，溅射时间分别为300s、10s交替和300s、40s交替，从而获得不同Nb掺杂含量的Nb:Ga2O3薄膜，其中薄膜厚度为250-260nm。
(3)将制备好的Nb:Ga2O3薄膜样品放入管式炉中进行氩气(Ar)保护退火。用机械泵将管式炉内气压抽至1Pa以下，通入高纯Ar(99.999％)，使工作气压维持在一个大气压下，管式炉开始升温，在温度升至1000℃后保温240min，之后自然降温到室温，退火全程持续通入高纯Ar(99.999％)。
(4)用紫外-可见光分光计测量了薄膜样品的吸收光谱，并计算了薄膜样品的禁带宽度，发现Nb:Ga2O3薄膜的禁带宽度均低于4.9eV，且随着Nb掺杂量的增加而减小。
实施例2
(1)采用抛光的n型硅片作为衬底(电阻率2～4Ωcm，厚度为0.3mm)。将衬底分别用甲苯、丙酮、乙醇和去离子水各自超声清洗15min后放入手套箱干燥1小时。
(2)利用射频磁控溅射设备以共溅射方式沉积Nb:Ga2O3薄膜材料。系统预真空度在1×10-3Pa以下。薄膜的生长气氛为Ar，工作气压为0.6Pa。Ga2O3和Nb2O5靶材的溅射功率均为80W，溅射时间为50min，获得4个厚度为250nm且Nb掺杂含量相同(掺杂质量百分比含量为1.07％)的Nb:Ga2O3薄膜样品。
(3)将制备好的3个Nb:Ga2O3薄膜样品分别放入管式炉中进行Ar、O2和N2气氛退火。用机械泵将管式炉内气压抽至1Pa以下，通入高纯Ar(99.999％)、O2(99.999％)或N2(99.999％)，之后使工作气压维持在一个大气压下，管式炉升温至1000℃后保温60min，之后自然降温到室温，退火全程持续通入高纯Ar、O2或N2。
(4)用紫外-可见光分光计测量了薄膜样品的吸收光谱，并计算了薄膜样品的禁带宽度，发现Nb:Ga2O3薄膜在O2、Ar或N2气氛中退火后禁带宽度均高于4.9eV，且Eg(N2气氛退火)>Eg(Ar气氛退火)>Eg(O2气氛退火)>Eg(未退火)。
实施例3
(1)采用抛光的n型硅片作为衬底(电阻率2～4Ωcm，厚度为0.3mm)。将衬底分别用甲苯、丙酮、乙醇和去离子水各自超声清洗15min后放入手套箱干燥1小时。
(2)利用射频磁控溅射设备以共溅射方式沉积Nb:Ga2O3薄膜材料。系统预真空度在1×10-3Pa以下。薄膜的生长气氛为Ar，工作气压为0.6Pa。Ga2O3和Nb2O5靶材的溅射功率均为80W，通过控制共溅射镀膜时间，获得多个相同Nb掺杂含量(掺杂质量百分比含量为1.5％)却不同膜厚的Nb:Ga2O3薄膜样品。设置镀膜时间分别为20min，30min，40min，60min，获得厚度分别为100nm，150nm，200nm和300nm的四个Nb:Ga2O3薄膜样品。
(3)将制备好的Nb:Ga2O3薄膜样品放入管式炉中进行氮气(N2)保护退火。用机械泵将管式炉内气压抽至1Pa以下，通入高纯N2(99.999％)，使工作气压维持在一个大气压下，管式炉开始升温，在温度升至1000℃后保温60min，之后自然降温到室温，退火全程持续通入高纯N2。
(4)用紫外-可见光分光计测量了薄膜样品的吸收光谱，并计算了薄膜样品的禁带宽度，发现Nb:Ga2O3薄膜的禁带宽度均高于4.9eV，且随着膜厚的减小而增大。

Claims (3)

1.利用Nb掺杂调谐Ga2O3禁带宽度的方法，其特征在于：
(1)使用射频磁控溅射设备在单晶抛光硅片上沉积一层Nb:Ga2O3薄膜材料；
Nb:Ga2O3薄膜的生长方式为以下两种之一：Nb靶材和Ga2O3靶材共溅射，获得掺杂均匀的Nb:Ga2O3薄膜材料；Nb靶材和Ga2O3靶材交替溅射，在衬底上分层生长Nb:Ga2O3薄膜材料；
(2)在管式炉中慢退火，慢退火温度为1000℃；恒温时间60-240min，慢速退火保护气体为Ar、N2或O2；通入保护气体后，开始升温，整个退火过程持续通气。
2.根据权利要求1所述的方法，其特征在于：共溅射或者交替溅射得到的薄膜材料厚度为100-300nm。
3.根据权利要求1所述的方法，其特征在于：共溅射得到的薄膜材料Nb掺杂质量百分比含量为0.8％-3％。
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Publication number Priority date Publication date Assignee Title
CN108878552A (zh) * 2018-07-03 2018-11-23 北京镓族科技有限公司 一种带隙纵向梯度分布Al和Fe共掺杂Ga2O3薄膜的制法
CN108878552B (zh) * 2018-07-03 2020-10-13 北京镓族科技有限公司 一种带隙纵向梯度分布Al和Fe共掺杂Ga2O3薄膜的制法
CN109554679A (zh) * 2019-01-21 2019-04-02 北京工业大学 一种利用Nb掺杂增强Ga2O3薄膜光催化降解有机污染物的方法
CN110195217A (zh) * 2019-06-26 2019-09-03 北京工业大学 一种制备β-Ga2O3薄膜方法
CN110195217B (zh) * 2019-06-26 2021-06-04 北京工业大学 一种制备β-Ga2O3薄膜方法

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