Multi-layered MoS2 film formed by high-temperature sputtering for enhancement-mode nMOSFETs
Multi-layered MoS2 film formed by high-temperature sputtering for enhancement-mode nMOSFETs
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DOI：
10.7567/jjap.54.04dn08
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发表时间：
2015-03
影响因子：
1.5
通讯作者：
T. Ohashi;K. Suda;S. Ishihara;N. Sawamoto;Shimpei Yamaguchi;K. Matsuura;K. Kakushima;N. Sugii;A. Nishiyama;Y. Kataoka;K. Natori;K. Tsutsui;H. Iwai;A. Ogura;H. Wakabayashi
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文献类型：
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作者：
T. Ohashi;K. Suda;S. Ishihara;N. Sawamoto;Shimpei Yamaguchi;K. Matsuura;K. Kakushima;N. Sugii;A. Nishiyama;Y. Kataoka;K. Natori;K. Tsutsui;H. Iwai;A. Ogura;H. Wakabayashi
采用高温溅射的方法在SiO2薄膜上形成多层MoS2薄膜，这是Si LSI技术的一种替代方法。结果表明，溅射沉积的二硫化钼薄膜载流子密度比剥落膜的载流子密度小1000倍。通过溅射，形成了两个不同的取向层，即SiO2/Si衬底的侧向层和垂直于衬底的层。由于硫空位数量的减少，横向层的载流子密度比垂直层低，这在一些研究中得到了普遍的讨论。然而，空位不足以描述载流子密度的显著降低。认为钠离子作为界面捕获电荷是载流子的主要来源之一。溅射，使我们能够确定钠污染水平，可以看作是适当的降低载流子密度；因此，该方法被认为是实现增强模式MoS2 mosfet的有效方法。此外，溅射也使我们能够形成大到晶圆尺寸的MoS2薄膜。因此，溅射沉积的MoS2薄膜是一种很有前途的后硅器件材料。
A multi-layered MoS2 film was formed on a SiO2 film by high-temperature sputtering, which is one of the alternative methods of Si LSI technology. It was found that the carrier density of a sputter-deposited MoS2 film is 1000 times smaller than that of an exfoliated one. By sputtering, two different orientations, namely a layer lateral to a SiO2/Si substrate and a layer perpendicular to the substrate, were formed. The lateral layer showed a lower carrier density than the perpendicular layer because of the decrease in the number of sulfur vacancies, as commonly discussed in several research studies. However, the vacancies are not sufficient for describing this significant reduction in carrier density. It is considered that a sodium ion functioning as an interface trapped charge is one of the main origins of carriers. Sputtering, which enables us to determine the sodium contamination level, can be seen as appropriate for reducing the carrier density; hence, this method is considered to be efficient in realizing enhancement-mode MoS2 MOSFETs. In addition, sputtering also enable us to form large-scale MoS2 films up to a wafer size. Therefore, a sputter-deposited MoS2 film is a promising material for post-silicon devices.