Method for manufacturing semiconductor device and method for manufacturing solid state image sensor using multiple insulation films

A method for manufacturing a solid state image sensor, the method comprising:

• preparing a structure including a semiconductor substrate having a pixel area having pixels each including a photoelectric converter and a peripheral area including a circuit containing a silicide layer to read out signals from the pixels, a first insulating film arranged on the pixel area of the semiconductor substrate, a second insulating film arranged on the first insulating film, a third insulating film arranged on the second insulating film, a fourth insulating film arranged on the peripheral area of the semiconductor substrate, a fifth insulating film arranged on the fourth insulating film, and a sixth insulating film arranged on the fifth insulating film;
• forming first contact holes extending through the first insulating film, the second insulating film, and the third insulating film;
• and
• forming second contact holes extending through the fourth insulating film, the fifth insulating film, and the sixth insulating film,
• wherein the first insulating film, the third insulating film, the fourth insulating film, and sixth insulating film have a first composition, and the second insulating film and the fifth insulating film have a second composition different from the first composition,
• the forming the first contact holes comprises etching the third insulating film using the second insulating film as an etching stopper, etching the second insulating film, and then etching the first insulating film under an etching condition different from an etching condition for the second insulating film, and
• the forming the second contact holes comprises etching the sixth insulating film using the fifth insulating film as an etching stopper, and then continuously etching the fifth insulating film and the fourth insulating film under the same etching condition for the fifth insulating film and the fourth insulating film.