Negative Resist Composition for High-Resolution Pattern Formation

The patent uses a composite resin system combining polycyclic alkene resin and polyester resin, where the polycyclic alkene resin provides high-resolution pattern formation and the polyester resin enhances etching resistance. This composite approach resolves the contradiction by integrating materials with complementary properties to achieve both desirable pattern formation and reliable pattern quality.

The patent modifies the chemical structure of the resin components by introducing specific functional groups (carboxyl groups, hydroxyl groups) and controlling molecular weight ranges. These parameter changes optimize the balance between pattern formation quality and etching resistance, enabling reliable resist pattern formation that conventional compositions cannot achieve.

The patent combines polycyclic alkene resin containing carboxyl groups (providing ArF excimer laser transparency) with polyester resin containing hydroxyl groups (providing etching resistance). The synergistic interaction between these components resolves the contradiction by allowing the transparent resin to enable light exposure while the crosslinking resin provides the necessary etching resistance.

The patent introduces crosslinking agents that selectively react with functional groups in specific regions of the resist film. This creates local variations in crosslinking density, allowing regions requiring transparency to maintain it while regions requiring etching resistance develop enhanced resistance through crosslinking, thus resolving the contradiction at the local level.

The patent carefully controls the molecular weight and functional group content of the polyester resin component to optimize crosslinking density. By adjusting these parameters, the patent achieves sufficient pattern definition through controlled crosslinking while preventing excessive swelling that would occur with higher crosslinking densities, thus resolving the contradiction between pattern definition and shape stability.

The patent uses resins with controlled molecular weight distributions and uniform functional group placement to ensure homogeneous crosslinking throughout the resist film. This homogeneous crosslinking prevents localized swelling and maintains uniform pattern dimensions, resolving the contradiction between achieving pattern definition and preventing shape distortion.