Patent ID: 8969941
Filing Date: 2015-03-03
Classification: H01L

Abstract:
1. A semiconductor device, comprising: at least one NAND string provided on an element region extending in a first direction in a surface of a semiconductor substrate, the NAND string comprising: a memory cell transistor having a stacked gate structure including a first insulating film provided part of the element region, a first conductive film provided on the first insulating film, a second insulating film provided on the first conductive film, and a second conductive film provided on the second insulating film; and a select transistor provided to be separated from the memory cell transistor on the element region, the select transistor having a stacked gate structure including a third insulating film provided on the other part of the element region, a third conductive film provided on the third insulating film, a fourth insulating film provided on the third conductive film, and a fourth conductive film provided on the fourth insulating film, the select transistor having a through-portion in the fourth insulating film to electrically connect the third conductive film and the fourth conductive film, wherein the memory cell transistor and the select transistor are arranged in the first direction, and the third conductive film is thicker than the first conductive film, and wherein a lower surface of the third conducting film is provided in the same plane as a lower surface of the first conducting film.