Material, particularly for an optical component for use in microlithography, and method for making a blank from the material

• US 7,691,766 B2
• Filed: 04/18/2007
• Issued: 04/06/2010
• Est. Priority Date: 04/20/2006
• Status: Expired due to Fees

• Current Assignee: Heraeus Quarzglas GmbH & Co. KG (Heraeus Holding GMBH)
• Original Assignee: Heraeus Quarzglas GmbH & Co. KG (Heraeus Holding GMBH)
• Inventors: Ochs, Stefan, Kuehn, Bodo
• Primary Examiner(s): Group; Karl E
• Assistant Examiner(s): Wiese; Noah S
• Application Number:
  US11/788,007
• Publication Number:
  US 20070248522A1
• Time in Patent Office: 1,084 Days
• Field of Search: 501/54, 501/133, 501/154, 423/324, 423/325, 423/335, 428/426
• US Class Current: 501/154
• CPC Class Codes: C03C 10/0009 containing silica as main constituent
• CPC Class Codes: C04B 2235/6565 Cooling rate
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/785 Submicron sized grains, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/786 Micrometer sized grains, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/94 Products characterised by their shape
• CPC Class Codes: C04B 2235/95 Products characterised by their size, e.g. microceramics
• CPC Class Codes: C04B 2235/9661 Colour
• CPC Class Codes: C04B 35/14 based on silica
• CPC Class Codes: C04B 35/645 Pressure sintering

Abstract

The invention is concerned with a material which shows low absorption for UV radiation having a wavelength below 250 nm, low birefringence, high chemical resistance and high radiation resistance and which is therefore particularly usable for making optical components for microlithography. According to the invention the material consists of synthetically produced quartz crystallites which form a polycrystalline structure and have a mean grain size in the range between 500 nm and 30 μm. The method according to the invention for making a blank from the material comprises providing granules consisting of synthetically produced quartz crystals having a mean grain size in the range between 500 nm and 30 μm, and sintering the granules to obtain a blank of polycrystalline quartz.

Claims

1. A material for an optical component, said material consisting essentially of synthetically produced quartz crystallites that form a polycrystalline structure and that have a mean grain size in a range between 500 nm and 30 μ

m.

2. The material according to claim 1, wherein the quartz crystallites have a mean grain size in a range between 750 nm and 20 μ

m.

4. The material according to claim 1, wherein quartz crystallites have pores with a size less than 1 μ

m.

5. The material of claim 1, wherein the material is used for an optical component in microlithography.

6. The material according to claim 1, wherein the quartz crystallites have a mean grain size in a range between 1 μ

m and 15 μ

m.

7. The material according to claim 1, wherein the quartz crystallites have a mean grain size in a range between 2 μ

m and 10 μ

m.

8. The material according to claim 1, wherein the quartz crystallites have pores with a size less than 0.5 μ

m.

9. The material according to claim 1, wherein said material has a total porosity of less than 1 ppm.

3. A material for an optical component, said material comprising synthetically produced quartz crystallites that form a polycrystalline structure and that have a mean grain size in a range between 500 nm and 30 μ

m, wherein said material has a total porosity of less than 1 ppm.

10. The material according to claim 3, wherein the quartz crystallites have a mean grain size in a range between 750 nm and 20 μ

m.

11. The material according to claim 3, wherein the quartz crystallites have pores with a size less than 1 μ

m.

12. The material of claim 3, wherein the material is used for an optical component in microlithography.

13. The material according to claim 3, wherein the quartz crystallites have a mean grain size in a range between 1 μ

m and 15 μ

m.

14. The material according to claim 3, wherein the quartz crystallites have a mean grain size in a range between 2 μ

m and 10 μ

m.

15. The material according to claim 3, wherein the quartz crystallites have pores with a size less than 0.5 μ

m.