A Roadmap for Disruptive Applications and Heterogeneous Integration Using Two-Dimensional Materials: State-of-the-Art and Technological Challenges

Abstract

This Mini Review attempts to establish a roadmap for two-dimensional (2D) material-based microelectronic technologies for future/disruptive applications with a vision for the semiconductor industry to enable a universal technology platform for heterogeneous integration. The heterogeneous integration would involve integrating orthogonal capabilities, such as different forms of computing (classical, neuromorphic, and quantum), all forms of sensing, digital and analog memories, energy harvesting, and so forth, all in a single chip using a universal technology platform. We have reviewed the state-of-the-art 2D materials such as graphene, transition metal dichalcogenides, phosphorene and hexagonal boron nitride, and so forth, and how they offer unique possibilities for a range of futuristic/disruptive applications. Besides, we have discussed the technological and fundamental challenges in enabling such a universal technology platform, where the world stands today, and what gaps are required to be filled.

Nature of Electrically Induced Defects in CVD-grown Monolayer MoS2

“…Chemical vapor deposition (CVD)-grown MoS2 films suffer from defects of varying nature 1,2,3,30 . Point defects like single atom vacancies occur due to non-uniform vapor pressure of precursors whereas line defects like grain boundaries are result of large nucleation density during the growth process 4,5 .…”

“…Although thermodynamic favorability results in inadvertent introduction of sulfur vacancies, controlled growth conditions also result in desirable Mo/S vacancy concentration 6,7 . While vacancy type and concentration determine the polarity and transport mechanism in FETs 30,31 , line defects impose serious performance limitations due to inter-grain charge transport 8 . Charge-transport across grain boundaries and in single crystal channels has been investigated thoroughly [8][9][10][11][12] and is found to be affected significantly by existing defects in MoS2.…”

Wafer-scale MoS2 with water-vapor assisted showerhead MOCVD

“…Being a member of the transition metal dichalcogenides (TMD) [1], MoS 2 unique electronic [2,3] and optical properties [4] combined with high mechanical flexibility [5,6] make it an attractive candidate for a potential new generation of wearable devices [7], flexible sensors [8][9][10] or nanoelectronics [2,11] as well as heterostructure research and development [12][13][14][15][16][17][18][19][20]. Therefore, after years of extensive study, the shift of academic focus from small, lab-scale synthesis methods towards the prototype applications and scalable processes is inevitable [21][22][23].…”

Possible structural and bond reconstruction in 2D ferromagnetic semiconductor VSe2 under uniaxial stress

“…There are two kinds of common structures for 2D TMDs: T structure and H structure. Among them, MoX 2 and WX 2 (X=S, Se, Te) are the most famous, and they have been explored intensively and various interesting devise have been realized from them [4][5][6][7][8][9][10] . In addition, transition metal can be replaced by rare earth atoms and chalcogen by halogens in these 2D structures, producing various interesting 2D materials [11][12][13][14] .…”

“…Recently, 2H VSe 2 single crystals were grown and VSe 2 nanoflakes were mechanically exfo-liated onto silicon substrates capped with a oxide layer, and then room-temperature ferromagnetic semiconductor was found in the nanoflakes and attributed to the 2H-phase of VSe 2 in the 2D limit 21 . Further exploration of H VSe 2 monolayer is highly desirable to obtain more insights and phenomena in order to seek potential applications for electronics, spintronics, and valleytronics 7,10 .…”