Masks for laser ablation technology: new requirements and challenges

Abstract

Laser ablation is used as a dry patterning process in which an intense beam of light from an excimer laser is used to directly pattern a material. The laser ablation patterning process is relatively new and has many advantages such as low cost and high throughput. This process has found extensive applications in the microelectronics industry for patterning of polymer materials. A typical laser ablation tool is very similar to a conventional optical wafer stepper, consisting of an illumination source, optics, mask and a substrate. The primary difference is the wavelength and the intensity of the light used in the ablation process. Conventional chromium coated quartz masks are incompatible with laser ablation due to a low damage threshold. This paper discusses a mask technology which has been developed specifically for excimer laser ablation. The mask fabrication processes and results are discussed.