Mask blank, mask for extreme ultraviolet photolithography, and manufacturing methods

Abstract

A mask or blanking mask includes a substrate having a first side and a second side opposite to the first side; a reflective multilayer disposed on the first side of the substrate; a capping layer disposed on the reflective multilayer; an absorbent layer disposed on the capping layer; and a conductive backside structure disposed on the second side of the substrate. The conductive backside structure includes materials having different etch rates in at least one etchant. A method of fabricating a mask or blanking mask includes forming the conductive backside structure on the second side of the substrate. A method of manufacturing a semiconductor device includes directing radiation to a mask and reflecting patterned light from the mask onto a photoresist layer disposed on a semiconductor substrate.

Claims

1. A blanking mask, comprising: a substrate including a first side and a second side opposite to the first side; a reflective multilayer disposed on the first side of the substrate; a capping layer disposed on the reflective multilayer; an absorbing layer disposed on the capping layer; and a conductive backside structure disposed on the second side of the substrate, wherein the conductive backside structure includes a first layer and a second layer, the first layer contacting a peripheral edge of the second side of the substrate, the second layer contacting the first layer, and a component of the first layer being different from a component of the second layer.

2. The blank mask as described in claim 1, wherein the first layer covers the second side of the substrate, the second layer covers the first layer, and the first layer is located between the second layer and the substrate.

3. The blank mask as described in claim 2, wherein the conductive backside structure further includes a third layer disposed on the second layer, and the second layer is located between the first layer and the third layer.

4. The blank mask as described in claim 1, wherein the first layer comprises an annular structure on the peripheral edge of the second side of the substrate.

5. A mask for extreme ultraviolet lithography, comprising: a reflective multilayer disposed on a first side of a substrate; a capping layer disposed on the reflective multilayer; an absorbent layer disposed on the capping layer; a circuit pattern formed through the absorbent layer and exposing a portion of the capping layer; and a conductive backside structure disposed on a second side of the substrate, wherein the second side is opposite to the first side, the conductive backside structure comprising a first material disposed on an edge portion of the second side of the substrate and a second material disposed on a central portion of the second side of the substrate, wherein the first material is different from the second material.

6. A method of manufacturing a mask, comprising: depositing a reflective multilayer stack on a first side of a substrate; forming a conductive backside structure on a second side of the substrate, wherein the conductive backside structure includes a first layer and a second layer, the first layer contacting the second side of the substrate, the second layer contacting the first layer, the conductive backside structure having at least one of the following properties: the second layer exhibits a higher etch rate than the first layer when etched in a fluorinated plasma, and the second layer exhibits a higher etch rate than the first layer when etched in a chlorinated plasma; depositing a capping layer on the reflective multilayer stack; depositing an absorber layer on the capping layer; and performing an etching operation to form a circuit pattern in the absorber layer to expose a portion of the capping layer, wherein the etching operation includes at least one of the following steps: etching the absorber layer with the fluorinated plasma, and etching the absorber layer with the chlorinated plasma.

7. The method of claim 6, wherein forming the conductive backside structure on the second side of the substrate comprises: depositing the first layer to cover the second side of the substrate; and depositing the second layer to cover the first layer, wherein the first layer is located between the second layer and the substrate.

8. The method as described in claim 7, wherein forming the conductive backside structure on the second side of the substrate further comprises: depositing a third layer on the second layer such that the second layer is located between the first layer and the third layer.

9. The method as described in claim 8, wherein the conductive backside structure further includes an additional property that, in at least one of the fluorinated plasma and the chlorinated plasma, the third layer has a higher etch rate than the first layer.

10. The method of claim 6, wherein forming the conductive backside structure on the second side of the substrate comprises: depositing the first layer on the second side of the substrate; depositing a photoresist layer on the first layer; exposing the photoresist layer to a pattern of radiation to form the exposed photoresist layer; developing the exposed photoresist layer to form an opening through the exposed photoresist layer, wherein the opening is surrounded by the developed photoresist layer; performing another etching operation using the developed photoresist layer as an etch mask to extend the opening into the first layer; and depositing the second layer in the opening.

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