Method for forming semiconductor structure with high aspect ratio

A method for forming a semiconductor structure, comprising:

• forming a first protruding structure, a second protruding structure, and a third protruding structure over a substrate;
• performing a depositing process to form a first insulation material layer between the first protruding structure and the second protruding process but not between the second protruding structure and the third protruding process;
• performing an insulation material conversion process onto the first insulation material layer to bend the first protruding structure and the second protruding structure toward opposite directions;
• forming a second insulation material layer over the first insulation material layer and between the second protruding structure and the third protruding structure;
• and
• performing a second insulation material conversion process onto the second insulation material layer,
• wherein a distance between the first protruding structure and the second protruding structure is smaller than a distance between the second protruding structure and the third protruding structure.

A method for forming a semiconductor structure, comprising:

• forming a first protruding structure over a substrate, wherein the first protruding structure has a first sidewall extending along a first direction;
• forming a first insulation material layer over a bottom portion of the first sidewall of the first protruding structure;
• and
• performing a first insulation material conversion process on the first insulation material layer to bend the first sidewall of the first protruding structure, so that the first sidewall of the first protruding structure extends along a second direction different from the first direction.