Abstract: A semiconductor memory device includes a lower stacked structure with lower metal lines on a substrate, an upper stacked structure with an upper metal line on the lower stacked structure, a vertical structure penetrating the upper and lower stacked structures and including a channel layer, a first cutting line through the upper and lower stacked structures, an upper supporter in a recess on the first cutting line, a second cutting line through the upper and lower stacked structures and spaced apart from the first cutting line, a sub-cutting line through the upper stacked structure while at least partially overlapping the vertical structure in the vertical direction, the sub-cutting line being between the first and second cutting lines, top surfaces of the upper supporter and sub-cutting line being coplanar, and a first interlayer insulating layer surrounding a sidewall of each of the upper supporter and the sub-cutting line.

Abstract: The present invention relates to an intermediate for preparing porous silicon oxycarbide, a method of preparing the same, and a lithium secondary battery including porous silicon oxycarbide prepared from the same as a negative electrode active material. According to the present invention, since an intermediate prepared by adding a polyhedral oligomeric silsesquioxane (POSS) to a reaction mixture for preparing silicon oxycarbide, which is composed of a polysiloxane polymer and an aromatic compound, is pyrolyzed to prepare porous silicon oxycarbide (SiOC), although the content of a free carbon region is lower compared to conventional silicon oxycarbide, the cage structure of the POSS is maintained in the pyrolysis to form many pores uniformly distributed in the SiOC matrix, and thus rapid diffusion of electrolyte ions is possible, and because the contents of SiO3C and SiO2C2 in the SiOC matrix are increased, a reversible capacity in the Si—O—C phase can be enhanced.