Abstract: A manufacturing method of a semiconductor device may include: forming a stack comprising first material layers and second material layers that are alternately stacked; forming an opening in the stack; forming a first seed layer in the opening; forming a first buffer layer by surface-treating the first seed layer; and forming a blocking layer by oxidizing the first seed layer through the first buffer layer.

Abstract: In a method of manufacturing a cathode active material for a lithium secondary battery, a preliminary lithium metal oxide particle is prepared. The preliminary lithium metal oxide particle is cleaned using a boron compound cleaning solution. A cathode active material for a lithium secondary particle includes a lithium metal oxide particle where a ratio of a B+ peak intensity relative to a sum of peak intensities of Li+, B+ and LiB+ fragments by a TOF-SIMS analysis is in a range from 0.03% to 1.5%.

Abstract: An atomic layer etching method using a ligand exchange reaction may include a substrate providing step of putting a substrate with a thin film formed thereon into a reaction chamber, a halogenated thin film forming step of forming a halogenated thin film on a surface of the thin film by infusing a halogenated gas into the reaction chamber, and an etching step of etching the halogenated thin film by infusing a ligand without a metal or metal precursor into the reaction chamber with the substrate with the halogenated thin film.

Abstract: The present disclosure relates to a method for producing natural killer (NK) cells. More specifically, the present disclosure relates to a method for producing NK cells, characterized in that peripheral blood mononuclear cells from which CD3-positive cells are removed are proliferated together with feeder cells, and the peripheral blood mononuclear cells are re-stimulated with feeder cells at the time of reaching a specific accumulated population doubling level. The present disclosure also relates to a method for producing NK cells, characterized in that NK cells are cultured under appropriate culture conditions by using a bioreactor. The production method according to the present disclosure has an advantage that NK cells having a high cell-killing ability and cell survival rate can be produced with high purity and at high efficiency in a short period of time by a clinically friendly method as compared with existing methods, thereby increasing the productivity of an NK cell therapy agent.