Method for making a photomask with multiple absorption levels

A photomask, comprising:

• a substrate;
• a plurality of layers of light-absorbing material disposed on the substrate;
• and
• at least one layer of buffer material disposed between a pair of adjacent layers of light-absorbing material, the buffer material being selectively etchable with respect to at least one of the layers of light-absorbing material,
• wherein a first layer of light-absorbing material has a first thickness and a second layer of light-absorbing material has a second thickness different than the first thickness.

A photomask, comprising:

• a substrate;
• a plurality of layers of light-absorbing material disposed on the substrate;
• and
• at least one layer of buffer material disposed between a pair of adjacent layers of light-absorbing material, the buffer material being selectively etchable with respect to at least one of the layers of light-absorbing material,
• wherein a first layer of light-absorbing material comprises a first material and a second layer of light-absorbing material comprises a second material different than the first material.

A method for manufacturing a photomask having multiple light-absorbing levels, the method comprising the acts of:

• providing a photomask substrate;
• disposing a first layer of a generally light-absorbing material onto the substrate,
• disposing a second layer of a buffer material onto the first layer, the second layer being selectively etchable relative to the first layer;
• disposing a third layer of a generally light-absorbing material onto the second layer, the third layer being selectively etchable relative to the second layer;
• forming a fourth layer of a buffer material onto the third layer, the fourth layer being selectively etchable relative to the third layer;
• forming a fifth layer of a generally light-absorbing material onto the fourth layer, the fifth layer being selectively etchable relative to the fourth layer;
• forming a first pattern window extending through only the fifth layer to define a first light-absorbing region having a first light-absorbing level;
• and
• forming a second pattern window extending through at least the fifth layer, the fourth layer, and the third layer to define a second light-absorbing region having a second light-absorbing level different than the first light-absorbing level.

A method for manufacturing a photomask having multiple light-absorbing levels, the method comprising the acts of:

• providing a substrate;
• disposing a first layer of a generally light-absorbing material onto the substrate, the first layer comprising one of amorphous silicon, chromium, titanium, titanium nitride, tungsten, and molybdenum;
• disposing a second layer of a buffer material onto the first layer, the second layer being selectively etchable relative to the first layer;
• and
• disposing a third layer of a generally light-absorbing material onto the second layer, the third layer being selectively etchable relative to the second layer.

A method of manufacturing a photomask, comprising the acts of:

• providing a substrate;
• disposing a first layer of light-absorbing material on the substrate, the first layer having a first thickness;
• disposing a first layer of etch-stop material on the first layer of light-absorbing material;
• and
• disposing a second layer of light-absorbing material on the first layer of etch-stop material, the second layer of light-absorbing material having a second thickness different than the first thickness.

A method of manufacturing a photomask having multiple light-absorbing levels, the method comprising the acts of:

• providing a substrate;
• forming a plurality of layers of light-absorbing material and a plurality of layers of etch-stop material in an alternating fashion on the substrate, wherein at least one layer of light-absorbing material is selectively etchable relative to an adjacent underlying layer of etch-stop material;
• and
• patterning the plurality of layers of light-absorbing material and the plurality of layers of etch-stop material to define a first light-absorbing region having a first light-absorption level and a second light-absorbing region having a second light-absorbing level different that the first light-absorbing level, wherein the first light-absorbing region comprises at least a portion of the plurality of layers of light-absorbing material, and wherein the second light-absorbing region comprises a lesser number of layers of light-absorbing material than the first light-absorbing region.

A method of manufacturing a photomask, comprising the acts of:

• providing a substrate;
• disposing N layers of light-absorbing material over the substrate, where N is an integer greater than 2 and at least one of the N layers comprises amorphous silicon;
• and
• disposing N−1 layers of etch-stop material between the respective N layers of light-absorbing material.