Photolithography mask and method of fabrication

Abstract

A novel mask for photolithography in semiconductor processing and fabrication method is disclosed. The mask includes a layer of transmissive material transparent to the wavelength of light to be used deposited thereon. The transmissive material is plasma etched in accordance with a pattern in photoresist deposited thereon to create trench portions in the transmissive material. A layer of absorbing material absorptive to the wavelength of light to be used is deposited within the trench portions. The surface of the mask is then planarized to create a substantially smooth mask layer having trench portions in the transmissive material and absorbing layer portions within the trench portions. If desired, a second layer of transmissive material can be deposited over the smooth mask layer to provide a protective cap to create an overall smooth, flat completed mask surface. The mask is useful for transmissive photolithography applications as well as reflective photolithography applications. The invention is also useful for forming a phase shifting mask.

Dependencies are inferred from the claim text.