Ultra-Large-Scale Step-Free Terraces Formed at the Bottom of Craters on Vicinal Si(111) Surfaces

Abstract

It is clarified that suboxides and interface traps are closely linked to threshold-voltage variation (ÁV th ) due to random telegraph noise (RTN) from an investigation of dependence of ÁV th on silicon-surface orientation: Si(100), (110), and (111). The amount of RTN traps increases with increasing amount of suboxides in the interfacial transition layer. With regard to the total amount of suboxides, the Si(110) surface orientation gives a larger amount than Si(100) and Si(111). Furthermore, we found that Si(110) has the potential to give fast RTNs with a larger ÁV th than Si(111). Accordingly, ÁV th for Si(110) is larger than those of Si(100) and Si(111). Attention should be paid to the possibility of the impact of RTN on Si(110) as the vertical plane of a three-dimensional device. #

Step Instabilities on Si(111) Vicinal Face near 1×1 ↔7 ×7 Transition Temperature during Sublimation

“…Thus, we probably cannot observe the motion of bunches of tight pairs consisting of a step and boundary. However, Homma and co-workers 29,30) formed a large flat terrace with a width greater than 10μm. On such a terrace, we can probably form a bunches of tight pairs consisting of a step and boundary.…”

Thin SiO2 layers on Si(111) with ultralow atomic step density

“…[10][11][12][13] Two different research groups have been successful in significantly reducing or completely removing steps from very large areas of silicon substrates. [14][15][16] It is reasonable to expect from these previous results that it should be possible to fabricate large atomically flat substrates of silicon with thin layers of thermal oxide ͑or other dielectric materials͒ having the same smooth morphology. These would be ideal for MOS device fabrication and also for studying the fundamental mechanisms of oxidation.…”

Precise control of epitaxy of graphene by microfabricating SiC substrate

“…9 The decrease of surface step density on smaller patterns is understood in analogy with the reduction of surface step density on microfabricated Si substrate. 11 On the smaller patterns, the surface diffusion length of surface adspecies emitted during the step retreat becomes larger than the length of the patterns in the direction of the step retreat. The surface steps are then gathered at the edges of patterns.…”

“…11,12 It has been demonstrated that spatial confinement of surface reactions on Si surfaces, e.g., homoepitaxy and sublimation, on microfabricated Si substrates induces self-ordering of steps and even step-free surfaces. 11,12 On EG formation on SiC, the Si sublimation from the SiC surface is the key reaction, 9 so that effective spatial confinement of Si sublimation is anticipated to suppress the step density and the microscopic thickness variation. Studies on epitaxial graphene on structured SiC substrates have already been made, but to form graphene nanoribbons at edges of the microstructures.…”

“…The surface step density decreases on the smaller patterns by gathering the surface steps at the peripheries of the patterns. 11 The threshold size of the triangle pattern is about 5 lm. Details of the suppression shall be explained later, by using Fig.…”