Method for manufacturing semiconductor structure

A method, comprising:

• forming patterned masks over a semiconductor substrate;
• etching the semiconductor substrate using the patterned masks as an etch mask to form semiconductor fins with a trench between the semiconductor fins;
• forming a first liner on exposed surfaces of the semiconductor fins and the semiconductor substrate;
• forming a second liner over the first liner, wherein surfaces of the patterned masks are exposed by the first and second liners;
• filling the trench with a dielectric material;
• and
• etching back the first liner, the second liner, and the dielectric material to form an isolation structure between the semiconductor fins.

A method, comprising:

• forming patterned masks over a semiconductor substrate;
• etching the semiconductor substrate using the patterned masks as an etch mask to form semiconductor fins with a trench between the semiconductor fins;
• forming a first liner on exposed surfaces of the semiconductor fins and the semiconductor substrate;
• after forming the first liner, performing a first annealing process in an oxygen-free environment;
• after performing the first annealing process, forming a second liner over the first liner;
• filling the trench with a dielectric material;
• and
• etching back the first liner, the second liner, and the dielectric material to form an isolation structure between the semiconductor fins.