Photosensitive material and method of photolithography

摘要

Methods and materials directed to solubility of photosensitive material in negative tone developer are described. The photosensitive material may include greater than 50% acid labile groups as branches to a polymer chain. In another embodiment, a photosensitive material, after exposure or irradiation, is treated. Exemplary treatments include applying a base to the photosensitive material.

主权项

1. A pattern forming method, comprising:
applying a photosensitive material to a substrate, wherein the photosensitive material solubility in negative tone developer decreases upon irradiation and wherein the photosensitive material includes:
a polymer backbone chain wherein greater than approximately 50% of the groups linked to the polymer backbone chain are acid labile groups, wherein each of the acid labile groups have the structure: the polymer backbone chain further comprising a plurality of lactone groups linked to the polymer backbone chain; exposing the photosensitive material to a patterned radiation beam; performing a post exposure bake (PEB) process after the exposing the photosensitive material; after the PEB, treating the photosensitive material with a base chemical, wherein the treating causes an opening of each of the plurality of lactone units from the polymer backbone chain to form a respective hydrophilic branch linked to the polymer backbone after contact with the base chemical; and after the treating, applying a developer for developing the photosensitive material, wherein a negative tone developer is applied to the photosensitive material having the opened plurality of lactone units.