IMAGE SENSOR WITH A CURVED SURFACE

• US 20140004644A1
• Filed: 04/08/2013
• Published: 01/02/2014
• Est. Priority Date: 04/13/2012
• Status: Active Grant

• Current Assignee: Stmicroelectronics France (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SA (STMicroelectronics NV), STMicroelectronics SAS (STMicroelectronics NV)
• Inventors: Roy, Franois, Michelot, Julien, Oddou, Jean-Pierre, Broussous, Lucile
• Granted Patent: US 9,099,604 B2
• Time in Patent Office: Days
• US Class Current: 438/57
• CPC Class Codes: H01L 27/14605 Structural or functional details relating to the position of the pixel elements, e.g. smaller pixel elements in the center of the imager compared to pixel elements at the periphery
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof

Abstract

A method for manufacturing an image sensor, including the successive steps of: forming columns of a semiconductor material; forming one or several pixels at a first end of each of the columns; and deforming the structure so that the second ends of each of the columns come closer to each other or draw away from each other to form a surface in the shape of a polyhedral cap.

Claims

1. A method for manufacturing an image sensor, comprising the successive steps or:

defining, in a semiconductor substrate extending on a semiconductor support with an interposed insulating layer, through trenches delimiting columns,

forming one or several pixels at a first end of each of the columns; and

deforming the structure so that the second ends of each of said columns come closer to each other or draw away from each other to form a surface in the shape of a polyhedral cap.

2. The method of claim 1, wherein the step of forming of columns comprises a step of definition, in a solid semiconductor, of trenches delimiting said columns.

4. The method of claim 1, wherein the columns have dimensions at the surface of the substrate smaller than 10 μ

m.

5. The method of claim 1, further comprising, after the trench forming step, a step of filling of the trenches with an insulating material.

6. The method of claim 5, further comprising, before the structure deformation step, a step of removal of the insulating material.

7. The method of claim 6, wherein the step of removal of the insulating material is followed by a step of filling of the trenches with a material.

8. The method of claim 1, further comprising, after the step of forming of columns, a step of forming of an interconnection stack on the side of the first end of the columns.

9. The method of claim 8, further comprising, after the step of forming of an interconnection stack, a step of installation of a handle followed by a removal of the semiconductor support and of the insulating layer.

10. The method of claim 9, wherein the step of installation of a handle on the interconnection stack is preceded by a step of forming, on the interconnection stack, of a layer of a material capable of deforming with no fracture.

11. The method of claim 9, wherein the step of installation of a handle on the interconnection stack is preceded by a step of etching of a cavity at the handle surface, said cavity being defined and positioned to coincide, at the installation, with the entire surface defined by the columns.

12. The method of claim 1, wherein the step of forming of columns is followed by a column wall restoring step.

13. The method of claim 1, wherein the columns are formed by plasma etching, pulsed plasma etching, or reactive ion etching.

3. (canceled)

14. (canceled)

15. (canceled)