Catadioptric Lens for Excimer Laser Lithography

光学光刻广泛用于制造 集成电路. 目前的系统使用传统的I- 线（356 nm波长）灯或照亮镜头， 将IC图案印刷到晶片上。 未来的系统将使用 激光器 迄今为止使用的所有光刻光学器件都是 折射型 在短紫外（UV）激光波长下， 下一代器件制造所需的几个 这种类型的透镜存在局限性。 这些限制 包括由于发射波长、热量 吸收由于高光子能量在紫外线，和光学 传输损耗（低效率）， 光 PI建议开发一种折反射光学系统， 高透光率、高分辨率、抗激光， 并且相对容易制造。 因为这样做 基于反射镜，光学畸变大大降低， 可以在不损坏光学器件的情况下使用功率电平。 我们有 在我们的实验室里用这种光学器件做了初步的实验， 分辨率达到0.4 μ m。 这种类型的发展 透镜将导致显着改善的高 分辨率成像系统的超大规模集成电路微光刻，一个关键的 制造集成电路步骤。

Optical lithography is widely used in the manufacture of integrated circuits. The current systems utilize conventional I- line (356nm wavelength) lamps or to illuminate the lenses that print the IC patterns onto wafers. Future systems will use laser. All of the lithography optics used to date have been the refractive type. At the short ultraviolet (UV) laser wavelengths required for next generation device manufacturing, several limitations exist for this type of lens. These limitations include light scattering because of shot wavelengths, heat absorption due to high photon energies in the UV, and optical transmission losses (poor efficiency) from high absorption of the light. The PI propose to develop a catadioptric optical system that has high optical transmission, high resolution, is laser-resistant, and relatively easy to manufacture. Because the optics are mirror-based, optical distortion is greatly reduced and very high power levels can be used without damaging the optics. We have made preliminary experiments in our lab with this type of optics, and achieved 0.4um resolution. The development of this type of lens would lead to significant improvements in the high resolution imaging systems for VLSI microlithography, a critical step in manufacturing integrate circuits.