Patent ID: 7514330

Claim:
A method of manufacturing a semiconductor device having a semiconductor substrate having an active area defined by two areas of isolation layer formed in the semiconductor substrate, the method comprising steps of: etching at least two predetermined parts of the active area to a first depth forming first recesses; filling a conductive layer in each of the first recesses; etching the active area between two conductive layers of the first recesses and a portion of each conductive layer adjoining the etched active area to a second depth forming a second recess having a sidewall and a bottom surface, wherein the second depth of the second recess is shallower than the first depth of the first recess, and wherein the two etched conductive layers formed at least along the second recess side wall are understepped gates; forming a source area in a portion of the semiconductor substrate outside the second recess, wherein the source area is in electrical contact with the understepped gate; and forming a drain area in a portion of the semiconductor substrate below the second recess bottom surface, wherein the drain area is in electrical contact with the understepped gate.