[14a-A407-1~8] 16.1 基礎物性・評価・プロセス・デバイス

▲ [14a-A407-3] The promise of anisotropic 2D materials: the Transition Metal Trichalcogenide (TMT)

〇Takashi Komesu¹、H. Yi²、S. Gilbert¹、A. Yost¹、A. Lipatov¹、A. Sinitskii¹、Ya. Losovyj³、P. Galiy⁴、J. Avila²、C. Chen²、M. Asensio²、P. Dowben¹ (1.Univ. of Nebraska、2.SOLEIL、3.Indiana Univ.、4.Ivan Franko Nat. U.)

キーワード：Transition metal trichalcogenides, nanospot angle resolved photoemission, electronic band structure

To develop new semiconductor technologies and, in fact, surpass silicon technology, the scaling of devices to transistor widths below 10 nm is essential. This poses problems for most materials, as few are perfect. Imperfections abound and in the limit of the very small scale can have disastrous effects, especially on device performance (in say a transistor). As transistor dimensions decrease, in principle, 2D semiconductor channel materials are highly desirable because this reduced the leakage currents, but edge effects become significant. In aiming for 2D semiconductor channel materials, here lies a challenge for materials science: to engineer a 2D material in which edge effects are not detrimental to transport as the channel width shrinks below 20 nm. Here, we discuss possible 2D materials, with highly anisotropic band structure, and with promising edge structure and chemistry. Transition metal trichalcogenide (TMT), like MX₃ (M=Ti, Zr, Hf; X=S, Se, Te), and In₄X₃ (X=Se, Te), are possible candidates for a semiconductor channel for a field effect transistor (FET) on the scale of a few nanometers. The band structure of titanium trisulfide (TiS₃) [1], ZrS₃ and In₄Se₃ [2] are all found to be highly anisotropic, consistent with transport measurements, and accompanied by few edge imperfections. TMT also have band gaps comparable to that of silicon. Such anisotropic 2D materials have great promise, indeed greater promise than graphene or the metal dichalcogenides, for the production of high performance 2D devices with sub-20 nm dimension. In this presentation, we are going to show our experimental electronic structure measurement results mainly on TiS₃ and ZrS₃ whisker materials.

[1] H. Yi, et al. Applied Physics Letters 112 (2018) 052102
[2] Ya. B. Losovyj, et al., Applied Physics Letters 92 (2008) 122107