Dual layer reticle blank and manufacturing process
AssigneeMicronic Laser Systems AB
InventorTorbjörn Sandström
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Abstract
The present invention relates to preparation of patterned reticles to be used as masks in the production of semiconductor and other devices. Methods and devices are described utilizing resist and transfer layers over a masking layer on a reticle. The methods and devices produce small feature dimensions in masks and phase shift masks. The methods described for masks are in many cases applicable to the direct writing on other workpieces having similarly small features, such as semiconductor, cryogenic, magnetic and optical microdevices.
Claims72
A method of creating by a pattern generator features on a mask blank having a reticle substrate, a masking layer, a transfer layer and a resist layer, including the steps:
- creating a latent image in the resist layer using a pattern generator;
- creating a plasma etch barrier corresponding to said latent image;
- directionally etching the transfer layer through said plasma etch barrier;
- directionally etching the masking layer through said transfer layer;
- and
- removing said transfer layer, exposing unetched portions of the masking layer.
A method of creating features on a reticle including a reticle substrate, a masking layer, a transfer layer and a resist layer, including the steps:
- exposing the resist layer using a pattern generator;
- developing the resist layer and selectively removing portions of the resist layer;
- directionally etching the transfer layer underneath the resist layer;
- directionally etching the masking layer underneath the transfer layer;
- and
- removing the transfer layer and exposing unetched portions of the masking layer.
Dependencies are inferred from the claim text.