Photomask and method of controlling transmittance and phase of light using the photomask
AssigneeSamsung Electronics Co., Ltd.
InventorsJin-hong Park, Seong-woon Choi
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Abstract
A photomask and a method of controlling a transmittance and phase of light using the photomask are disclosed. The photomask comprises a transparent substrate, and a plurality of lattices formed on the back face of the transparent substrate. The plurality of lattices are binary lattices, each having a duty ratio and a tilt angle. The duty ratio and tilt angle are controlled together in order to simultaneously control transmittance and phase of light transmitted through the photomask.
Claims19
A photomask, comprising:
- a transparent substrate having a front face and a back face;
- and,
- a lattice structure diffracting light and formed on the back face of the transparent substrate, wherein the lattice structure comprises binary lattices, each of the binary lattices having a duty ratio and a tilt angle controlling phase and transmittance for the diffracted light.
A method of controlling transmittance and phase of light with a photomask, wherein the photomask comprises a transparent substrate, the method comprising:
- selecting a transmittance and a phase for light transmitted through a predetermined region of the transparent substrate;
- determining a duty ratio and a tilt angle corresponding to the selected transmittance and phase;
- preparing the photomask by forming binary lattices having the duty ratio and the tilt angle on the predetermined region of the transparent substrate;
- and,
- exposing light through the photomask.
A method of controlling transmittance and phase of light in an exposure process, the method comprising:
- providing a photomask, wherein the photomask comprises:
- a transparent substrate having a front face and a back face;
- and,
- a lattice structure formed on the back face of the transparent substrate and diffracting light;
- wherein the lattice structure comprises binary lattices, each of the binary lattices having a duty ratio and a tilt angle controlling phase and transmittance of the diffracted light;
- and,
- applying incident light through the photomask.
Dependencies are inferred from the claim text.