Wafer-scale low-disorder 2DEG in ²⁸Si/SiGe without an epitaxial Si cap

Wafer-scale arrays of epitaxial ferroelectric nanodiscs and nanorings.

Wafer-scale arrays of well-ordered Pb(Zr(0.2)Ti(0.8))O3 nanodiscs and nanorings were fabricated on the entire area (10 mm x 10 mm) of the SrRuO3 bottom electrode on an SrTiO3 single-crystal substrate using the laser interference lithography (LIL) process combined with pulsed laser deposition. The shape and size of the nanostructures were controlled by the amount of PZT deposited through the pat...

100-GHz transistors from wafer-scale epitaxial graphene.

The high carrier mobility of graphene has been exploited in field-effect transistors that operate at high frequencies. Transistors were fabricated on epitaxial graphene synthesized on the silicon face of a silicon carbide wafer, achieving a cutoff frequency of 100 gigahertz for a gate length of 240 nanometers. The high-frequency performance of these epitaxial graphene transistors exceeds that o...

Wafer-scale epitaxial graphene growth on the Si-face of hexagonal SiC „0001... for high frequency transistors

Up to two layers of epitaxial graphene have been grown on the Si-face of 2 in. SiC wafers exhibiting room-temperature Hall mobilities up to 2750 cm2 V−1 s−1, measured from ungated, large, 160 200 m2 Hall bars, and up to 4000 cm2 V−1 s−1, from top-gated, small, 1 1.5 m2 Hall bars. The growth process involved a combination of a cleaning step of the SiC in a Si-containing gas, followed by an annea...

Wafer-scale homogeneity of transport properties in epitaxial graphene on SiC

Long spin relaxation times in wafer scale epitaxial graphene on SiC(0001).

We developed an easy, upscalable process to prepare lateral spin-valve devices on epitaxially grown monolayer graphene on SiC(0001) and perform nonlocal spin transport measurements. We observe the longest spin relaxation times τ(S) in monolayer graphene, while the spin diffusion coefficient D(S) is strongly reduced compared to typical results on exfoliated graphene. The increase of τ(S) is prob...