| 摘要 |
A new method is provided for the creation of an attenuated phase shifting mask. A transparent mask substrate is provided, a layer of attenuating phase shifting material is deposited on the surface of said transparent mask substrate, a layer of opaque material is deposited on the surface of said layer of attenuating phase shifting material. A layer of photoresist is deposited over the surface of the layer of opaque material. The photoresist is exposed by E-beam, creating a mask pattern and a guard ring pattern in the photoresist. The (E-beam) exposed photoresist is removed, the pattern created in the layer of photoresist is used to etch a mask pattern in the layer of opaque material and the layer of attenuating phase shifting material. The remaining photoresist is exposed to UV radiation in the region of the mask pattern and partially in the region of the guard ring. The (UV) exposed photoresist is removed, the remaining photoresist is reduced in height after which the openings of the mask pattern in the opaque layer are increased in size, the outside edge of the guard ring accurately defines the boundary of the device. The remaining photoresist is removed from the layer of opaque material.
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