Substrate distortion measurement

• US 9,645,512 B2
• Filed: 02/09/2012
• Issued: 05/09/2017
• Est. Priority Date: 07/06/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Smeets, Erik Marie Jose
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): AKANBI, ISIAKA O
• Application Number:
  US13/370,102
• Publication Number:
  US 20120270150A1
• Time in Patent Office: 1,916 Days
• Field of Search: 356339-401
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70783 Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight
• CPC Class Codes: G03F 7/7085 Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load

Abstract

A substrate distortion measurement apparatus comprising one or more optical detectors arranged to measure the locations of pits or holes provided in a substrate, a memory arranged to store previously determined locations of the pits or holes in the substrate, and a comparator arranged to compare the measured locations of the pits or holes with the previously determined locations of the pits or holes, to determine distortion of the substrate.

Claims

1. A substrate comprising:

a photosensitive layer;

a mark layer arranged below the photosensitive layer and having at least 1000 marks, and

a reflective layer arranged between the mark layer and the photosensitive layer so as to fill spaces between the marks, said reflective layer being reflective to a radiation beam of a first wavelength,

wherein said mark layer is transmissive to the radiation beam at said first wavelength so that said radiation beam propagating through said mark layer is reflected by said reflective layer, and

wherein said substrate is a polygonal substrate and wherein at least one side of the polygonal substrate has a length of at least 50 cm.

2. The substrate of claim 1, wherein said photosensitive layer is a resist layer.

3. The substrate of claim 1, wherein said marks face away from said photosensitive layer.

4. The substrate of claim 1, wherein said substrate comprises a plastic layer.

5. The substrate of claim 1, wherein said mark layer comprises at least 1000000 marks.

6. The substrate of claim 1, wherein said marks include pits.

7. The substrate of claim 1, wherein said marks are arranged in rows.

8. The substrate of claim 1, wherein the marks are of equal length and are separated by a gap of equal length.

9. The substrate of claim 1, wherein the mark layer is between the photosensitive layer and a base layer forming the substrate.

10. The substrate of claim 1, wherein the mark layer including the marks is transparent to visible radiation.

11. A substrate comprising:

a photosensitive layer;

a mark layer arranged below the photosensitive layer and having at least 1000 marks,

a reflective layer arranged between the mark layer and the photosensitive layer,

wherein the reflective layer is configured to reflect a beam of light to be used to illuminate a first side of the substrate that is opposite a second side of the substrate on which said photosensitive layer is arranged, and

wherein the marks form an array of pits on a surface of the mark layer facing the reflective layer, and

wherein the reflective layer is arranged on the mark layer so as to cover each of said marks and fill spaces between the marks.

12. The substrate of claim 11, wherein the mark layer including the marks is transparent to visible radiation.

13. The substrate of claim 11, comprising a base layer, wherein the mark layer is arranged between the base layer and the reflective layer, said base layer being transparent at a radiation wavelength and said reflective layer being opaque at said radiation wavelength.

14. The substrate of claim 13, wherein the base layer is made of a material selected from the group consisting of polycarbonate, quartz, glass and silicon dioxide.

15. The substrate of claim 11, wherein the mark layer is constructed and arranged to provide distortion information of said substrate.