Epitaxial Growth of Large‐Scale 2D CrTe₂ Films on Amorphous Silicon Wafers With Low Thermal Budget

Abstract

Abstract2D van der Waals (vdW) magnets open landmark horizons in the development of innovative spintronic device architectures. However, their fabrication with large scale poses challenges due to high synthesis temperatures (>500 °C) and difficulties in integrating them with standard complementary metal‐oxide semiconductor (CMOS) technology on amorphous substrates such as silicon oxide (SiO2) and silicon nitride (SiNx). Here, a seeded growth technique for crystallizing CrTe2 films on amorphous SiNx/Si and SiO2/Si substrates with a low thermal budget is presented. This fabrication process optimizes large‐scale, granular atomic layers on amorphous substrates, yielding a substantial coercivity of 11.5 kilo‐oersted, attributed to weak intergranular exchange coupling. Field‐driven Néel‐type stripe domain dynamics explain the amplified coercivity. Moreover, the granular CrTe2 devices on Si wafers display significantly enhanced magnetoresistance, more than doubling that of single‐crystalline counterparts. Current‐assisted magnetization switching, enabled by a substantial spin–orbit torque with a large spin Hall angle (85) and spin Hall conductivity (1.02 × 107 ℏ/2e Ω⁻¹ m⁻¹), is also demonstrated. These observations underscore the proficiency in manipulating crystallinity within integrated 2D magnetic films on Si wafers, paving the way for large‐scale batch manufacturing of practical magnetoelectronic and spintronic devices, heralding a new era of technological innovation.

Critical behavior of quasi-two-dimensional ferromagnet Cr1.04Te2

“…5(d), pinpointing a tricritical point at 250 K and 480 Oe. At low fields below T C , the phase may transition from multidomain to single domain [30] or involve a ferromagnetic and antiferromagnetic competition, as theorized and observed in Cr x Te 2 compounds. [26,38,66] Additionally, we have compiled critical exponents and their models for other 2D vdW ferromagnetic materials in Table 2.…”

“…[14,[21][22][23][24] With decreasing thickness, CrTe 2 exhibits layer-dependent magnetic anisotropy transition and anomalous thickness dependence of T C . [25,26] Recently, gi-ant topological Hall effect (THE) [27,28] and spin-orbit torque devices [29,30] have been realized in CrTe 2 -based all vdW heterostructures. More intriguingly, the vdW gaps in CrTe 2 readily accommodate Cr atoms in various concentrations through the self-intercalation process, [31] resulting in a rich family of binary chromium tellurides, Cr x Te 2 , such as CrTe, [32] Cr 0.87 Te, [33] Cr 5 Te 6 , [15] Cr 4 Te 5 , [34] Cr 3 Te 4 , [35] Cr 2 Te 3 , [36] Cr 5 Te 8 , [16] Cr 0.62 Te, [37] Cr 1.2 Te 2 , [38,39] Cr 4.14 Te 8 , [40] and CrTe 3 .…”