COLLIMATOR BONDING STRUCTURE AND METHOD

• US 20110261239A1
• Filed: 04/21/2010
• Published: 10/27/2011
• Est. Priority Date: 04/21/2010
• Status: Active Grant

• Current Assignee: Eotech, LLC
• Original Assignee: Intevac
• Inventors: Fowler, Douglas, Yin, Edward, COSTELLO, Kenneth A., Roderick, Kevin J.
• Granted Patent: US 8,698,925 B2
• Time in Patent Office: Days
• US Class Current: 348/294
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 1/20 Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating preparation of surfaces in particular ways, see the relevant classes for the treatments or the materials treated, e.g. C04B, C23C
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H01L 27/14689 MOS based technologies
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

An image sensor is disclosed that includes a solid state semiconductor imager having a metallized catch pad, a collimator having a metallized layer that faces a sensor anode, the metallized layer joined with the metallized catch pad to form a metal bond between the solid state semiconductor imager and the collimator. Methods of making the joined solid state semiconductor imager and collimator assembly are also disclosed.

Claims

1. An image sensor comprising:

a solid state semiconductor imager comprising a backside thinned pixel array sensor and having a passivated silicon surface wherein a portion of the passivated silicon surface includes a pixel array region;

a silicon collimator; and

a metal bond inside the pixel array region joining the passivated silicon surface of the solid state semiconductor imager to the silicon collimator.

2. The image sensor of claim 1, wherein the metal bond comprises a thermo-compressioned metallized catch pad and metal layer.

3. The image sensor of claim 1, wherein the metal bond comprises a brazed metallized catch pad and metal layer.

4. The image sensor of claim 1, wherein the metal bond comprises a plurality of metal bonds interspersed on the passivated silicon surface.

5. The image sensor of claim 4, wherein the plurality of metal bonds are interspersed inside and outside of the pixel array region.

6. An image sensor comprising:

a solid state semiconductor imager comprising a sensor anode and having a metallized catch pad inside a pixel array region; and

a collimator having a metallized layer that faces the sensor anode, the metallized layer joined to the metallized catch pad to form a metal bond.

7. The image sensor of claim 6, wherein the metallized catch pad comprises a top metal layer, an adhesion layer and a barrier layer.

8. The image sensor of claim 6, wherein the metallized catch pad comprises a top metal layer and a barrier layer.

9. The image sensor of claim 6, wherein the metallized catch pad comprises a gold layer, a titanium layer and a SiO_xN_y layer.

10. The image sensor of claim 6, wherein the collimator further comprises an adhesion layer between a collimator body of the collimator and the metallized layer.

11. The image sensor of claim 6, wherein the solid state semiconductor imager comprises an imaging surface, wherein a portion of the imaging surface comprises a pixel array region.

12. The image sensor of claim 11, wherein the plurality of metallized catch pads are positioned inside and outside of the pixel array region.

13. The image sensor of claim 6, wherein the solid state semiconductor imager is a backside thinned pixel array sensor having a passivated surface.

14. The image sensor of claim 6, wherein the metal bond is formed by a thermo-compression process.

15. The image sensor of claim 6, wherein the metal bond is formed by a brazing process.

16. A method of making an image sensor comprising:

aligning a collimator with a solid state semiconductor imager; and

joining the collimator with the solid state semiconductor imager to form a metal bond between the collimator and the solid state semiconductor imager, the metal bond positioned inside a pixel array region of the solid state semiconductor imager.

17. The method of claim 16 wherein joining the collimator with the solid state semiconductor imager to form the metal bond comprises performing a thermo-compression process.

18. The method of claim 16 wherein joining the collimator with the solid state semiconductor imager to form the metal bond comprises performing a brazing process.

19. The method of claim 16 wherein joining the collimator with the solid state semiconductor imager to form the metal bond comprises performing a soldering process.

20. The method of claim 16 further comprising:

depositing a barrier layer on the solid state imaging sensor;

depositing an adhesion layer on the barrier layer; and

depositing a top metal layer on the adhesion layer.

21. The method of claim 16 further comprising:

depositing an adhesion layer on the collimator; and

depositing a bottom metal layer on the adhesion layer.

22. The method of claim 17 wherein the solid state semiconductor imager comprises a metallic catch pad and the collimator comprises a metallized layer, and wherein joining the collimator with the solid state semiconductor imager to form the metal bond comprises joining the metallic catch pad and the metallized layer.