OPTICALLY TRANSPARENT AND ELECTRICALLY CONDUCTIVE COATINGS AND METHOD FOR THEIR DEPOSITION ON A SUBSTRATE

• US 20140295330A1
• Filed: 10/12/2012
• Published: 10/02/2014
• Est. Priority Date: 10/14/2011
• Status: Active Grant

• Current Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung), Fundacio Institut de Ciencies Fotoniques
• Original Assignee: Institucio Catalana De Recerca I Estudis Avancats
• Inventors: Pruneri, Valerio, Carrilero, Albert, Peters, Jan-Hendrik
• Granted Patent: US 9,519,209 B2
• Time in Patent Office: Days
• US Class Current: 430/5
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G03F 1/22 Masks or mask blanks for imaging by radiation of 100nm or shorter wavelength, e.g. X-ray masks, extreme ultraviolet [EUV] masks; Preparation thereof
• CPC Class Codes: G03F 1/38 Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof

Abstract

The present inventions relates to a substrate for a photolithographic mask comprising a coating deposited on a rear surface of the substrate, wherein the coating comprises (a) at least one electrically conducting layer, and (b) wherein a thickness of the at least one layer is smaller than 30 nm, preferably smaller than 20 nm, and most preferably smaller than 10 nm.

Claims

1. A substrate for a photolithographic mask comprising a coating deposited on a rear surface of the substrate, the coating comprising:

a. at least one electrically conducting layer; and

b. wherein a thickness of the at least one layer is smaller than 30 nm, preferably smaller than 20 nm, and most preferably smaller than 10 nm.

2. The substrate of claim 1, wherein the at least one layer comprises an optical transmittance of more than 20%, preferably more than 40% and most preferably more than 60%.

3. The substrate of claim 1, wherein the at least one layer comprises a sheet resistance of smaller than 200 Ω

/sq, preferably smaller than 100 Ω

/sq, and most preferably of smaller than 50 Ω

/sq.

4. The substrate of claim 1, wherein the at least one layer comprises at least one metal and/or wherein the at least one metal comprises nickel (Ni), chromium (Cr), aluminum (Al), gold (Au), silver (Ag), copper (Cu), titanium (Ti), wolfram (W), indium (In), platinum (Pt), molybdenum (Mo), rhodium (Rh) and/or zinc (Zn) and/or mixtures of at least two of these metals.

5. The substrate of claim 1, wherein the at least one layer comprises graphene and/or a multilayer structure of graphite.

6. The substrate of claim 1, wherein the at least one layer comprises at least one first layer and at least one second layer, wherein the at least one first layer comprises at least one first metal and the at least one second layer comprises at least one second metal and/or graphene.

7. The substrate of claim 1, wherein the at least one layer comprises at least one first layer comprising at least one metal and at least one second layer comprising at least one metal oxide and/or at least one metal nitride.

8. The substrate of claim 1, wherein the at least one layer comprises at least one first layer comprising at least one graphene single layer or graphene multilayer structure and at least one second layer comprising at least one metal oxide and/or at least one metal nitride.

9. The substrate of claim 1, wherein the substrate comprises a material having a low thermal expansion coefficient, and/or wherein the substrate comprises fused silica.

10. The substrate of claim 1, wherein the at least one layer comprises an area of 148 mm×

148 mm, and/or wherein the thickness of the at least one layer varies less than ±

5%, preferably less than ±

2% across the area of the at least one layer.

11. The substrate of claim 1, wherein a composite Young'"'"'s modulus of the at least one layer deposited on the substrate and the substrate comprises a range of 20 GPa-70 GPa, preferably 30 GPa-60 GPA, and most preferably 40 GPa-50 GPa.

15. The method of claim 1, further comprising the step of forming a metal oxide from a metal in the at least one layer using a thermal treatment of the at least one layer in an ambient atmosphere and/or using a thermal treatment in an oxygen plasma atmosphere.

16. The substrate of claim 1 in which the at least one layer has an optical transmittance of more than 60% and a sheet resistance of smaller than 200 Ω

/sq.

17. The substrate of claim 1 in which the at least one layer has an optical transmittance of more than 60% and the at least one layer comprises at least one of nickel (Ni), chromium (Cr), aluminum (Al), gold (Au), silver (Ag), copper (Cu), titanium (Ti), wolfram (W), indium (In), platinum (Pt), molybdenum (Mo), rhodium (Rh), or zinc (Zn), or a mixture of at least two of these metals.

18. The substrate of claim 1 in which the at least one layer has an optical transmittance of more than 60% and the at least one layer comprises graphene and/or a multilayer structure of graphite.

19. The substrate of claim 1 in which the at least one layer has an optical transmittance of more than 60% and the at least one layer comprises at least one first layer and at least one second layer, wherein the at least one first layer comprises at least one first metal and the at least one second layer comprises at least one second metal and/or graphene.

20. The substrate of claim 1 in which the at least one layer has an optical transmittance of more than 60% and the at least one layer comprises at least one first layer comprising at least one metal and at least one second layer comprising at least one metal oxide and/or at least one metal nitride.

12. A method for depositing a coating on a substrate of a photolithographic mask, the method comprising:

a. depositing at least one electrically conducting layer on the substrate; and

b. wherein a thickness of the at least one layer is smaller than 30 nm, preferably smaller than 20 nm, and most preferably smaller than 10 nm.

13. The method of claim 12, wherein depositing the at least one layer comprises a physical vapor deposition method and/or wherein the physical vapor deposition method comprises a sputter deposition method.

14. The method of claim 12, wherein depositing the at least one layer comprises a thermal evaporation of a material of the at least one layer, and/or wherein depositing the at least one layer comprises an evaporation of the material of the at least one layer by an electron beam.