Sub-wavelength structures for reduction of reflective properties

• US 6,897,469 B2
• Filed: 05/02/2003
• Issued: 05/24/2005
• Est. Priority Date: 05/02/2003
• Status: Expired due to Term

• Current Assignee: DRS Network & Imaging Systems, LLC (Leonardo S.p.A.)
• Original Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Inventors: Meissner, Edward G., Gooch, Roland W., Syllaios, Athanasios J., Schimert, Thomas R.
• Primary Examiner(s): Blum, David S.
• Application Number:
  US10/428,745
• Publication Number:
  US 20040219704A1
• Time in Patent Office: 753 Days
• Field of Search: 438/48, 257/10, 257/678, 257/680, 257/704
• US Class Current: 257/10
• CPC Class Codes: B81B 7/00 Microstructural systems; Auxiliary parts of microstructural devices or systems
• CPC Class Codes: G02B 1/118 having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures

Abstract

A method for manufacturing optically-transparent lids includes etching sub-wavelength structures on a surface of a lid wafer. The structures may be arrayed in a hexagonally closed-packed pattern.

Claims

1. A lid wafer for an integrated circuit device comprising:

a first side;

a second side;

a cavity disposed within the first side;

one or more sub-wavelength structures disposed on the first side, wherein the one or more sub-wavelength structures are smaller in diameter and height than a wavelength of incident light; and

one or more sub-wavelength structures disposed on the second side wherein the one or more sub-wavelength structures are smaller in diameter and height than a wavelength of incident light.

2. The lid wafer of claim 1, wherein the one or more sub-wavelength structures are arrayed in a hexagonal close-packed pattern.

3. The lid wafer of claim 1, wherein the height of each one or more sub-wavelength structure is a function of the index of refraction of the lid wafer.

4. The lid wafer of claim 1, wherein the spacing between respective sub-wavelength structures is a function of the diameter of respective individual one or more sub-wavelength structures and the index of refraction of the lid wafer.

5. The lid wafer of claim 1, further comprising a low index of refraction material deposited between the one or more sub-wavelength structures on the first side.

6. The lid wafer of claim 1, further comprising a low index of refraction material deposited between the one or more sub-wavelength structures on the second side.

7. A lid wafer for an integrated circuit device comprising:

a first side;

a second side;

a cavity disposed within the first side;

one or more sub-wavelength structures disposed within the cavity;

one or more sub-wavelength structures disposed on the second side;

a fill material deposited between the one or more sub-wavelength structures on the first;

a fill material deposited between the one or more sub-wavelength structures on the second side, wherein the one or more sub-wavelength structures are arrayed in a hexagonal close-packed pattern, and wherein the one or more sub-wavelength structures are smaller in diameter and height than the wavelength of any incident light in the infrared spectrum, wherein the height of respective sub-wavelength structures is a function of the index of refraction of the lid wafer, and wherein the spacing between respective sub-wavelength structures is a function of the diameter of each respective sub-wavelength structure and the index of refraction of the lid wafer.