Semiconductor device employing silicon nitride layers with varied hydrogen concentration

A semiconductor device comprising:

• a semiconductor substrate;
• a transistor which has a gate insulation film, said transistor being formed in said semiconductor substrate;
• and
• a plasma SiN film disposed on said semiconductor substrate, said plasma SiN film having a lower film in which an amount of hydrogen contained gradually increases toward its top face from its bottom face and an upper film in which an amount of hydrogen contained is fixed to a constant value substantially equal to an amount of hydrogen contained in said top face of said lower film.

A semiconductor device comprising:

• a semiconductor substrate;
• a transistor having a gate insulation films and formed in said semiconductor substrate;
• a first plasma SiN film disposed on said semiconductor substrate;
• and
• a second plasma SiN film disposed on said first plasma SiN film in contact with said first plasma SiN film,
• wherein said first plasma SiN film has a lower amount of hydrogen than said second plasma SiN film.