Glass ceramic for ultraviolet lithography and method of manufacturing thereof
An extreme ultraviolet mask and method of manufacture thereof includes: providing a glass-ceramic block; forming a glass-ceramic substrate from the glass-ceramic block; and depositing a planarization layer on the glass-ceramic substrate.
1. A method of manufacturing of an extreme ultraviolet mask blank comprising:
forming a glass-ceramic substrate from a glass-ceramic block, the glass-ceramic block having a high spatial frequency roughness (HSFR) value;
forming a liquid planarization layer on the glass-ceramic substrate using flowable chemical vapor deposition; and
curing the planarization layer to form a hardened planarization layer,
wherein the hardened planarization layer has a surface roughness of under 0.6 nm rms and an HSFR value lower than the HSFR value of the glass-ceramic substrate.
2. The method as claimed in claim 1 wherein the planarization layer comprises silicon, oxygen, and carbon.
3. The method as claimed in claim 1 wherein curing comprises using an ultraviolet curing process.
4. The method as claimed in claim 1 wherein the glass-ceramic substrate has a coefficient of thermal expansion of ±0.007×10 −7 /K.
5. The method of claim 1 , wherein forming the planarization layer includes depositing a layer comprising silicon, oxygen, and carbon and curing the layer to form the hardened planarization layer on the glass-ceramic substrate.
6. The method of claim 5 wherein the glass-ceramic substrate has a coefficient of thermal expansion of ±0.007×10 −7 /K.
7. The method of claim 5 , wherein the hardened planarization layer planarizes a surface of the glass-ceramic substrate without changing properties the glass-ceramic substrate.
8. The method of claim 5 , wherein curing comprises steam or ozone curing.
9. The method of claim 5 , wherein curing comprises ultraviolet curing.
10. The method of claim 5 , wherein the glass-ceramic substrate comprises lithium alumino-silicate.
11. The method of claim 5 , further comprising forming a multilayer stack which reflects extreme ultraviolet light on the hardened planarization layer.
12. The method of claim 1 , wherein the planarization layer is a SiN based film, the method further comprising converting the SiN based film to a SiO/SiO 2 hardened planarization layer.
13. The method of claim 1 , wherein the glass-ceramic substrate comprises lithium alumino-silicate.
14. The method of claim 1 , further comprising forming a multilayer stack which reflects extreme ultraviolet light on the hardened planarization layer.