Semiconductor device having a conductive portion below an interlayer insulating film and method for producing the same

A semiconductor device comprising a SRAM cell unit having a pair of first and second drive transistors, a pair of first and second load transistors and a pair of first and second transfer transistors, wherein

• each of the transistors comprises a semiconductor raised portion protruding from a substrate plane, a gate electrode extending over the semiconductor raised portion from the top onto the opposite side faces of the semiconductor raised portion, a gate insulating film existing between the gate electrode and the semiconductor raised portion, and source and drain regions provided in the semiconductor raised portion;
• the semiconductor raised portions of the transistors are arranged with their longitudinal direction extending along a first direction;
• the first drive transistor and the first transfer transistor have a common first semiconductor raised portion, the second drive transistor and the second transfer transistor have a common second semiconductor raised portion, the first load transistor has a third semiconductor raised portion adjacent to the first semiconductor raised portion, and the second load transistor has a fourth semiconductor raised portion adjacent to the second semiconductor raised portion;
• and
• the gate electrodes of the first drive transistor and the first load transistor are formed of a common first conductor, the gate electrodes of the second drive transistor and the second load transistor are formed of a common second conductor, and the conductors are arranged with their longitudinal direction extending along a second direction vertical to the first direction;
• an interlayer insulating film is provided on a substrate including the SRAM cell unit;
• a first buried conductor interconnect is connected to the first conductor, the drain region of the second load transistor, the drain region of the second drive transistor and one of the source and drain regions of the second transfer transistor, and formed on the interlayer. insulating film;
• and
• a second buried conductor interconnect is connected to the second conductor, the drain region of the first load transistor, the drain region of the first drive transistor and one of the source and drain regions of the first transfer transistor, and formed on the interlayer insulating film.