Papers by Keyword: Patterned Substrate

Abstract: The recent process in the fabrication of the ordered Ge/Si quantum dots (QDs) is reviewed. The fabrication step generally started on the preparation of patterned substrate prepared in advance by using several interesting methods, such as photo lithography, focus ion beam (FIB), reactive ion etching (RIE), and extreme ultraviolet lithography (EUV-IL) et al, which are introduced briefly in this article. Here, we’d like to focus on the detailed process of nanosphere lithography (NSL) which has the advantages of less cost and higher product compared with the referred methods. The ordered Ge nanostructures always show as Hexagonal close-packed array on the patterned Si substrate and have the advantages of potential applications in electronic and optoelectronic devices.

Abstract: Recent progress in the growth of ordered Ge/Si quantum dots (QDs) is reviewed. We focus on the detailed progresses of the Ge/Si multiple layers QDs and the preparation of Ge/Si QDs by ion beam irradiation. In addition, the growth of Ge/Si QDs on patterned substrate by using different preparation methods are also well discussed, such as nanosphere lithography technology, extreme ultra-violet interference lithography technology, nanoimprint lithography technology, etc.

Abstract: In this work we report on SiC epitaxial growth by vapour-liquid-solid (VLS) mechanism on on-axis 4H-SiC(0001) substrates which were previously patterned to form mesa structures. The liquid phase was set to Al70Si30. At 1100°C, it led to very high homoepitaxial lateral growth (140 µm/h) with pronounced spiral growth and in plane anisotropy of growth rate. Upon temperature increase to 1200 °C, this spiral growth was suppressed and the lateral growth was further increased up to 180 µm/h. The in-plane versus out-of-plane anisotropy of growth rate was found to be as high as 60 at this temperature and 46 at 1100°C.

Abstract: In this work we report on the study of twin boundary (TB) evolution during heteroepitaxial growth of 3C-SiC on patterned 4H-SiC(0001) substrate by vapour-liquid-solid (VLS) mechanism. Ge₅₀Si₅₀ melt was used at a temperature of 1450°C. 3C-SiC deposit was obtained on top and outside the mesas. Some lateral enlargement of these mesas was observed but it was systematically homoepitaxial. Elimination of TBs inside the 3C-SiC deposit on top of the mesas was observed for specific mesa shape and/or orientation of the sidewalls. Though three–fold or six-fold symmetry mesas are recommended for TB elimination, originally circular mesas lead also to the same result due to initial faceting toward hexagonal shape.

Abstract: Patterned substrates are good candidates to enhance the arrangement of nanodomains in block copolymer thin films. Here, I theoretically demonstrate the possibility to self-assemble block copolymers on top of physically or chemically patterned substrates. The presence of substrate pattern not only enhances the alignment of polymers, but also induces novel new morphologies which were not present in the bulk phase diagram.

Abstract: The evaluation of elastic property for thin diamond-like carbon (DLC) films has been presented with buckle analysis of compressive stressed film on patterned substrate. When substrate has been patterned with adhesion release layer, the morphologies of buckle configuration on patterned layer has been controlled from straight sided (Euler) buckle to nonlinear telephone cord type buckle with respect to the pattern width. By using the simple equation for Euler buckle, the elastic modulus has been easily calculated, shown well consistent with the results by nano-indentation test.