Patent ID: 7615813

Claim:
A semiconductor device comprising: a semiconductor substrate; a first concave portion formed in the semiconductor substrate and buried with an isolation insulating film; a second concave portion formed in the semiconductor substrate and having a depth from a top surface of the semiconductor substrate, the depth being equal to a depth of the first concave portion; a first gate insulating film formed on a side surface of the second concave portion; and a first gate electrode formed on the first gate insulating film; a third concave portion formed in the semiconductor substrate and adjacent to the second concave portion in a row direction; a fourth concave portion formed in the semiconductor substrate and adjacent to the second concave portion in a column direction; a fifth concave portion formed in the semiconductor substrate and adjacent to the fourth concave portion in the row direction; a second gate insulating film extending from a side surface of the fifth concave portion to a bottom surface of the fourth concave portion; and a second gate electrode formed on the second gate insulating film, wherein the first gate insulating film and the first gate electrode extend from the side surface of the second concave portion to a bottom surface of the third concave portion, and wherein a first contact that is connected to the first gate electrode is formed above the bottom surface of the third concave portion, and a second contact that is connected to the second gate electrode is formed above a bottom surface of the fourth concave portion.