Polysilazane perhydride solution and method of manufacturing a semiconductor device using the same

A method of manufacturing a semiconductor device comprising:

• successively forming a gate insulating film, a first gate electrode film and a stopper film above a semiconductor substrate;
• forming an element isolation trench in the semiconductor substrate having the gate insulating film, the first gate electrode film and the stopper film;
• coating a polysilazane perhydride solution above the semiconductor substrate having the element isolation trench to form a polysilazane perhydride film, the polysilazane perhydride solution comprising dibutyl ether having a butanol concentration of 30 ppm or less, and polysilazane perhydride dissolved in the dibutyl ether;
• subjecting the polysilazane perhydride film to oxidation in an atmosphere containing water vapor to form a silicon dioxide film;
• selectively removing the silicon dioxide film deposited on the stopper film to leave the silicon dioxide film in the element isolation trench, thereby forming an element isolating insulation film;
• removing the stopper film to expose a surface of the first gate electrode film;
• removing an upper portion of the element isolating insulation film to expose an upper portion of side of the first gate electrode film;
• and
• forming a second gate electrode film, via an interelectrode insulating film, over the first gate electrode film having an upper portion of side thereof being exposed and over the element isolating insulation film having an upper portion thereof being removed.