Abstract: A method and apparatus for the production of transparent phase reticule mask for projecting high intensity light--such as that used for direct laser ablation of materials from substrates--is disclosed. The transparent phase reticule mask includes first portions which are for scattering light beyond the solid angle of an imaging system and second transparent portions which scatter light to an angle where projection by an imaging system can occur. Phase reticule mask configurations are disclosed including a known phase reticule mask which has gratings, and a new phase reticule mask having random phase roughening for the scattering of light. Random phase roughening includes imparting to the roughened area a mean solid angle of scattering that exceeds the solid angle of collection of an image system. Thus, the total fraction of incident light is below the ablation threshold and constitutes the dark patterned region of the mask.

Abstract: An apparatus for using and a process of using a Fresnel zone plate array is utilized for processing materials. An optically stable frame receives coherent light and passes the coherent light through beam processing optics such as a collimator, a beam expanding telescope and an aperture. Thereafter, the beam is routed to scanning mirrors immediately overlying a Fresnel zone plate array. The Fresnel zone plate array has a plurality of discrete subapertures with each subaperture containing image information at a discrete working distance from the plate; each image produced by a subaperture of the Fresnel zone plate array typically differs from adjacent images from adjacent subapertures typically in size, shape or gain. The beam is scanned and registered to a discrete selected subaperture on the plate to cause an image from the subaperture to form on a work piece located at the working distance of a scanned subaperture.

Abstract: An object is projected through the lens system to be corrected to the image plane where the position of the diffraction limited ideal image is readily ascertainable. At least one primary image defect or Seidel Aberration is measured. These aberrations include distortion, curvature of field or Petzval curvature, spherical aberration, coma, and astigmatism. Interferometry is one technique typically used to measure the aberrations of the system. Based on the measurements, the location of an apparent object is computed. The apparent object is an imaginary location of the object which would cause the image of the object to register to the diffraction limited ideal image. Although only one corrector plate may be required to achieve the desired optical system performance improvements, in the preferred embodiment at least two corrector plate mounting planes are designed and mounts made for the insertion of first and second corrector plates to correct beam convergence and focus to the ideal image.

Abstract: A metallic substrate such a copper foil has an etch barrier such polyimide, Saran Wrap.RTM., or other plastic applied. This barrier is thereafter selectively etched or ablated with a laser, for example by passing the light through a phase reticle or phase mask having at least the image information for the fine metallic lines thereon. The remaining barrier then acts in a second etch process to remove the underlying metallic layer. A wet or dry (such as RIE) etch may be employed. Over conventional photoresist exposure methods, the developer and resist steps are eliminated. The laser can precisely pattern the barrier in a single step with the remainder of the production of the required metallic fine lines relying on a simple wet etch, a process whose control parameters are well understood and consume little time. Alternately, a process for the direct ablation of metallic layers is disclosed.