Method for fabricating continuous space variant attenuating lithography mask for fabrication of devices with three-dimensional structures and microelectronics
US6534221B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1999 |
| Grant date | Mar 18, 2003 |
| Priority date | — |
| Expiry date | Mar 26, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/001
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for fabricating a mask for patterning a radiation sensitive layer in a lithographic printer is disclosed. An attenuating (absorptive or reflective) layer is coated over a substantially transparent base substrate such that after processing a two-dimensional spatially varying attenuating pattern is created with a continuously or discretely varying transmission or reflection function. In accordance with the present invention the two-dimensional attenuating pattern is formed by e-beam patterning of radiation sensitive layer to create a three-dimensional surface relief pattern. This pattern is transferred to the attenuating layer by an anisotropic etch, typically a directional reactive plasma etch. The attenuation of this radiation absorbing or reflecting layer varies with layer thickness. In one embodiment of this invention the attenuation of the mask would vary spatially in a continuous manner. In a second embodiment the attenuation of the mask (either reflective or absorptive) would vary spatially in discrete steps. One application of the mask created by this invention would be used to replicate a three-dimensional surface relief onto a second substrate by lithographic means…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.