Polymer, Positive And Negative Photosensitive Resin Compositions, Patterning Process, Method For Forming Cured Film, Interlayer Insulating Film, Surface Protective Film, And Electronic Component

A polymer comprising:

• a structural unit represented by the following general formula (1) and/or (2);
• and a structural unit represented by the following general formula (3) and/or (4),
• wherein X1 represents a tetravalent organic group, R1 to R4 are each different from or identical to each other and represent a monovalent organic group having 1 to 15 carbon atoms and optionally containing a heteroatom or represent a hydrogen atom, provided that at least one of R1 to R4 represents a monovalent organic group having 1 to 15 carbon atoms and optionally containing a heteroatom, and L represents a divalent organic group excluding a —O—C(═O)— bond or a —C(═O)—O— bond or represents a divalent atom,
• wherein X2 represents a divalent organic group, and R1 to R4 and L are as defined above,
• wherein X3 represents a tetravalent organic group that is identical to or different from the X1, “s” represents 0 or 1, Z represents a divalent bonding group, and when s=0, the two aromatic rings in the formula are directly bonded without an intervening bonding group,
• wherein X4 represents a divalent organic group that is identical to or different from the X2, and “s” and Z are as defined above.