Method for manufacturing semiconductor substrate, method for etching substrate, and composition for surface modification

A method for etching a substrate, the method comprising:

• a step of dry-etching a substrate comprising a layer comprising a Low-k material;
• and
• a step of treating the dry-etched substrate with a composition for surface modification,
• wherein the composition for surface modification contains:
• (A) a silane coupling agent represented by General Formula (1) and/or a derivative thereof;
• and (B) water,
• wherein, in General Formula (1), A and B each independently represent a hydrogen atom, a hydroxy group, a hydrocarbon group, or an organic group containing a nitrogen atom, and at least one of A and B represents a hydrogen atom;
• X and Y each independently represent an alkyl group, an alkoxy group, a hydrogen atom, a halogen atom, or a hydroxy group;
• Z represents an alkoxy group or a hydroxy group;
• and n represents a number.

A composition for surface modification of a substrate comprising a layer comprising a Low-k material, the composition comprising:

• (A) a silane coupling agent represented by General Formula (1) and/or a derivative thereof;
• and (B) water,
• wherein, in General Formula (1), A and B each independently represent a hydrogen atom, a hydroxy group, a hydrocarbon group, or an organic group containing a nitrogen atom, and at least one of A and B represents a hydrogen atom;
• X and Y each independently represent an alkyl group, an alkoxy group, a hydrogen atom, a halogen atom, or a hydroxy group;
• Z represents an alkoxy group or a hydroxy group;
• and n represents a number.