Method for producing a semiconductor device

A method for fabricating a semiconductor device comprising the steps of:

• forming at least first and second electrodes having an insulating film thereon on a semiconductor substrate, a thickness of the insulating film on a contact region of the first electrode being smaller than that on the second electrode;
• forming an impurity diffusion region in the semiconductor substrate between the first and second electrodes;
• forming insulating side walls on the electrodes;
• forming an insulation layer over the electrodes and the impurity diffusion region to form a multiple level insulator on at least a portion of the electrodes;
• etching the insulation layer covering a portion of the impurity diffusion region until a surface of the impurity diffusion region is exposed;
• at substantially the same time the insulating layer is etched, etching a part of the multiple level insulator on the contact region of the first electrode until a surface of the first electrode is exposed;
• and
• forming an interconnecting conductive layer over the electrodes and the impurity diffusion region to interconnect the exposed surfaces of the impurity diffusion region with the contact region of the first electrode.