Extreme ultraviolet (euv) radiation pellicle formation method
AssigneeInternational Business Machines Corporation
InventorDario L. Goldfarb
Life of this patent
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Abstract
An extreme ultraviolet (EUV) photolithography pellicle with at least 70% transmissivity to EUV can be formed from a layer of semiconductor material applied to a substrate. The bottom surface of the layer can be exposed by forming support structure(s) from the substrate. Semiconductor material between the exposed surfaces can become the pellicle by anodizing until an objective is reached, such as a particular transmissivity, range of size of pores formed, pellicle region thickness, elapse of a period, and/or another objective indicative of 70% transmissivity to EUV for the semiconductor material between the exposed surfaces.
Claims20
A method of forming an extreme ultraviolet (EUV) pellicle for protection of a photomask, the method comprising:
- preparing a pellicle region of a pellicle layer of a semiconductor material, including:
- applying a layer of the semiconductor material to an exposed surface of a substrate to form the pellicle layer,
- forming at least one support structure from the substrate, and
- removing a portion of the substrate to expose a pellicle region of a previously covered bottom surface of the pellicle layer;
- and
- anodizing at least the pellicle region of the pellicle layer until a transmissivity of the pellicle region to EUV electromagnetic radiation including a range of wavelengths of electromagnetic radiation of from about 4 nanometers to about 125 nanometers reaches at least a desired transmissivity value.
A method of forming a pellicle with at least a desired transmissivity to electromagnetic radiation in a range of wavelengths of from about 4 nanometers to about 125 nanometers, the method comprising:
- forming a pellicle layer of a semiconductor material on a wafer, the wafer including at least a substrate layer;
- applying a bottom protective layer to a bottom surface of the wafer;
- applying a top protective layer to a top surface of the pellicle layer;
- applying at least one masking element to the bottom masking layer;
- removing an unmasked portion of the bottom protective layer to expose a portion of a bottom of the wafer;
- removing the at least one masking element to expose at least one corresponding remaining portion of the bottom protective layer;
- removing the exposed portion of the bottom of the wafer, a remaining portion of the bottom protective layer, and the top protective layer to expose a portion of a lower surface of the pellicle layer and at least a portion of a top surface of the pellicle layer corresponding to the exposed bottom surface of the pellicle layer, thereby forming a processing article;
- and
- anodizing the processing article to form the pellicle throughout a pellicle region of the pellicle layer at least corresponding to the exposed portion of the bottom surface of the pellicle layer to form the pellicle.
A method of forming an extreme ultraviolet (EUV) porous semiconductor pellicle for protecting a photolithographic photomask, the pellicle having a transmissivity of at least 70% in a range of wavelengths in the electromagnetic radiation spectrum of from about 4 nanometers to about 125 nanometers, the method comprising:
- forming a pellicle layer of a semiconductor material on a wafer, the wafer including at least a handle wafer, a bottom oxide (BOX) layer, and a substrate layer;
- applying a bottom protective layer to a bottom surface of the handle wafer;
- applying a top protective layer to a top surface of the pellicle layer;
- applying at least one masking element to the bottom protective layer;
- removing an unmasked portion of the bottom protective layer to expose a portion of a bottom of the handle wafer;
- removing the at least one masking element to expose at least one corresponding remaining portion of the bottom protective layer;
- removing the exposed portion of the bottom of the handle wafer, removing a portion of a bottom of the BOX layer exposed thereby to expose a portion of a bottom of the substrate layer, and removing the exposed portion of the bottom of the substrate layer, a remaining portion of the bottom protective layer, and the top protective layer to expose a portion of a lower surface of the pellicle layer and at least a portion of a top surface of the pellicle layer corresponding to the exposed bottom surface of the pellicle layer, thereby forming a processing article;
- and
- anodizing the processing article to form the pellicle throughout a pellicle region of the pellicle layer at least corresponding to the exposed portion of the bottom surface of the pellicle layer to form the pellicle.
Dependencies are inferred from the claim text.