Semiconductor device and method for fabricating a semicondutor device including first and second hydrogen diffusion preventing films

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

• forming a gate electrode over a semiconductor device with a gate insulation film therebetween;
• forming a source/drain diffused layer in the semiconductor substrate on both sides of the gate electrode;
• forming a first insulation film over the semiconductor substrate, the gate electrode and the source/drain diffused layer;
• forming first contact hole in the first insulation film down to the source/drain diffused layer;
• burying first conductor plug in the first contact hole;
• forming over the first insulation film a capacitor including a lower electrode, a dielectric film formed over the lower electrode and an upper electrode formed over the dielectric film;
• forming a first hydrogen diffusion preventing film for preventing the diffusion of hydrogen over the first insulation film and the capacitor;
• forming a second insulation film over the first hydrogen diffusion preventing film, the second insulation film being contacted with the first hydrogen diffusion preventing film;
• polishing a surface of the second insulation film to planarize the surface of the second insulation film;
• forming a second hydrogen diffusion preventing film for preventing the diffusion of hydrogen over an entire top surface of the second insulation film, the second hydrogen diffusion preventing film being contacted with the second insulation film;
• forming second contact hole in the first hydrogen diffusion preventing film, the second insulation film and the second hydrogen diffusion preventing film down to the lower electrode or the upper electrode;
• forming third contact hole in the first hydrogen diffusion preventing film, the second insulation film and the second hydrogen diffusion preventing film down to the first conductor plug;
• burying second conductor plug in the second contact hole and third conductor plug in the third contact hole;
• forming an interconnection over the second hydrogen diffusion preventing film in contact with the second conductor plug or the third conductor plug, without etching the second hydrogen diffusion preventing film;
• and
• forming a third insulation film over the second hydrogen diffusion preventing film and the interconnection.