The present invention provides a semiconductor chip that provides a semiconductor device with high reliability and low leak current, and a method of manufacturing such a semiconductor chip, and more specifically, provides a semiconductor chip comprising memory portions and a peripheral circuit portion, where the memory portions and the peripheral circuit portion are formed in a main surface portion of the semiconductor chip, a thickness of the sections of the semiconductor chip passing through the main surface portion in which the memory portions are formed is larger than a thickness of sections of the semiconductor chip passing through the main surface portion in which the peripheral circuit portion is formed, and a method of manufacturing such a semiconductor chip.