Method of producing static random access memory device having thin film transister loads

A method of producing a semiconductor memory device comprising a memory cell formed on a semiconductor substrate, the memory cell comprising two transfer transistors which each have a gate electrode, two driver transistors, two thin film transistor loads and two word lines respectively coupled to gate electrodes of the transfer transistors, the method comprising:

• forming a field insulator layer on the semiconductor substrate;
• forming a gate insulator layer on the semiconductor substrate after forming the field insulator layer;
• forming a gate electrode of a driver transistor by forming and patterning a first conductor layer on the semiconductor substrate, the first conductor layer having a top surface;
• forming a first insulator layer on the top surface of the first conductor layer after impurity regions are formed in the semiconductor substrate, using the field insulator layer and the first conductor layer as masks;
• forming and patterning a second conductor layer on the first insulator layer;
• forming a second insulator layer on the second conductor layer;
• forming and patterning a third conductor layer on the second insulator layer;
• forming a third insulator layer on the third conductor layer, the third insulator having a top surface;
• forming a contact hole which extends from the top surface of the third insulator layer to the top surface of the first conductor layer, the contact hole extending through the second conductor layer and the third conductor layer to form side surfaces in the second conductor layer and the third conductor layer;
• and
• forming a fourth conductor layer which extends into the contact hole to make contact with the top surface of the first conductor layer, the side surface of the second conductor layer and the side surface of the third conductor layer.