The invention relates to a metal oxide semiconductor chip, which comprises a heavy doping semiconductor substrate, an epitaxial layer, at least one element and a metal pattern layer, wherein the heavy doping semiconductor substrate forms a drain doping region; the epitaxial layer is arranged on the semiconductor substrate; the upper surface of the epitaxial layer is defined with an active region, a terminal region and a scribe line remaining region, an etching wall is arranged on the scribe line remaining region and extends to an upper surface of the semiconductor substrate; the edge region of the upper surface of the semiconductor substrate is exposed outside; the element is arranged in the active region and provided with a grid electrode and a source electrode; the metal pattern layer is positioned on the epitaxial layer and the semiconductor substrate and comprises a grid electrode contact pad, a source electrode contact pad and a drain electrode metal pattern, wherein the grid electrode contact pad is electrically connected with the grid electrode, the source electrode contact pad is electrically connected with the source electrode, and at least part of the drain electrode metal pattern is positioned on the upper surface of the semiconductor substrate. The design of the chip can reduce breakover loss; and a making method of the metal oxide semiconductor chip can reduce the making cost and is beneficial to the subsequent packaging and assembling procedure.