Showing papers on "Mask inspection published in 1993"

Phase-shifting lithography: Maskmaking and its application

Abstract: The use of phase‐shifting masks (PSMs) allows substantial improvement in resolution and depth‐of‐focus of optical systems. Before the advantages of PSMs can be realized in a production process, several problems of mask technology must be solved. In order to advance PSMs from a development tool to a production tool for very large scale integration (VLSI) devices, the technologies concerning mask fabrication, mask inspection, and mask repair have been investigated. A silicone‐based resist has been developed for simplifying the mask fabrication processes. The printability and detectability of shifter defects have been investigated in order to specify the requirements of systems of PSM manufacture and inspection. The developed silicone‐based resist has been applied for mask defect repair. These technologies can bring PSMs closer to being a practical production tool for VLSI. To verify the effectiveness of PSMs for device manufacturing, PSMs have been successfully applied to gate definition of a high‐speed GaA...

Mask inspection device

Abstract: PURPOSE: To make accurate inspection irrespective of the shape of inspection pattern by inspecting whether any defect exists on the basis of the inspection image acquired from the inspection light of a short and a long wavelength component, and referencing the result obtained. CONSTITUTION: The short wavelength component of the first inspection light 121 is solely taken out, and the rear surface of a mask 10 is irradiated therewith. The transmitted light is put incident to the first photographing means 150, and the attached foreign matter, etc., on the mask 10 are shielded against the light so as to generate a darkness, and there image formation takes place. This is computed for each picture element where the first inspection pattern A/D converted 171 is identical to the design pattern 175, and inspection 176 is made whether defect exists. On the other hand, only the long wavelength component of the second inspection light 130 is taken out, and therewith the surface of the mask 10 is irradiated. The reflected light thereby is put incident to the second photographing means 160, and image formation takes place where Cr film, etc., on the mask surface serves as light part, and inspection 177 is conducted whether defect exists from this second inspection pattern and the second design pattern of the differentiated image. A defect judging circuit 178 compares the first defect pattern with the second and passes judgement whether the defect is due to poor pattern formation on the mask or to attachment of any foreign matter. COPYRIGHT: (C)1994,JPO

Materials Issues In X-Ray Lithography

Abstract: In this paper, an outline of materials-related activities in the national X-Ray Lithography Program is given. The program is directed towards the development of sub-quarter micron design-rule x-ray lithography together with the ancillary technologies required to fabricate defect-free x-ray masks. Work done at the Naval Research Laboratory is highlighted and used for examples. Most materials related work occurs in conjunction in the x-ray mask fabrication process. Topics discussed include electron beam-matter interaction in the mask patterning process, membane fabrication, stress control in thin membranes, reactive-ion etching of absorber-layers, mask inspection and repair.

Corner-rounding study

Abstract: Precise measurement of pattern corner rounding is essential for determining the quality of current and next-generation photomask reticles. Using an appropriate test target with precise critical dimensions (CDs) and feature sizes, photomasks were written on an ETEC CORE 2564 laser writer with changes in focus from -1.0 to 1.0 micrometers at various exposure doses (mj/cm2). Using this methodology, the corner rounding of the CORE 2564 imaged feature was changed and compared to the ETEC MEBES III system generated pattern. The KLA 239HRS photomask inspection system was used to examine the effects of corner rounding at 0.25 micrometers with its most sensitive detectors at a 0.05 tolerance level. The optimization of writing tool performance and process parameters was enabled in two ways: by using the KLA 239HRS system, which did on-line biasing and rounding in 0.12 micrometers increments; and by using the Leitz AMS200 CD measurement tool, Micron Focused-Ion-Beam (FIB) system, and a binary image system, which measured the rounding of the mask features.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Status of x-ray mask inspection and repair

Abstract: The status of x-ray mask inspection and repair at the IBM Advanced Mask Facility is presented. Defect classification and sources are presented along with some preliminary results from a defect printing study done at the Advanced Lithography Facility.