Abstract: An elevated toy train track is formed from multiple platform sections (12, 14, 16, 18) and a stabilizing ring (48) that are attachable together to form a ring-like structure (10). Each platform section has at least two lateral sides (34, 36), where one lateral side (34) has ridges (42) and the other lateral side (36) has slots (46). During assembly, the ridges (42) on one platform section are placed in snug engagement with complementary slots (46) of an adjacent platform section, until all platform sections are joined together. The stabilizing ring (48) is attached, using threaded fasteners (60), to the joined platform sections (12, 14, 16, 18) to form the ring-like structure (10). A train track (20) is attached to the ring-like structure, or can be integrally molded to the platform sections. The structure is attachable to the central pole (64, 66) of a Christmas tree, thus providing an elevated toy train track.

Abstract: A first monocrystalline group III-V compound semiconductor layer is formed on an Si substrate. The surface of the first monocrystalline group III-V compound semiconductor layer is polished. A second monocrystalline group III-V compound semiconductor layer is grown on the polished surface by a metal organic chemical vapor deposition, by using as a group III source material at least partially a source material of group III atoms bonded to ethyl radical at the initial stage of growth, and thereafter by using as the group III source material a source material of group III atoms bonded to methyl radical. A grown layer with a flat surface can be obtained. The surface flatness can be improved further by adding In as a group III element.