Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, comprising:

• forming an insulating member on a structure, an upper surface of the structure including a first portion with a first height, a second portion with a second height higher than the first height, a third portion with a third height lower than the second height;
• and
• forming a plurality of openings in the insulating member,
• wherein the forming the plurality of openings comprises:
• etching the insulating member under a first condition that makes an etching amount per unit time and unit area of the insulating member larger as a size of the opening becomes larger;
• and
• etching the insulating member under a second condition that makes the etching amount per unit time and unit area of the insulating member larger as the size of the opening becomes smaller, after the etching the insulating member under the first condition,
• in the etching the insulating member under the first condition,
• a first opening, which has a first width and whose bottom surface is higher than the second height, is formed on the first portion with the first height,
• a second opening, which has a second width and whose bottom surface is higher than the second height, is formed on the second portion with the second height, and
• a third opening, which has a third width larger than the first width and the second width and whose bottom surface is higher than the second height, is formed on the third portion with the third height, and
• in the etching the insulating member under the second condition, portions under the first opening and the second opening out of the insulating member are removed so as to expose the first portion with the first height and the second portion with the second height while leaving a portion of the insulating member between the third opening and the third portion.