Image sensor with light-reflecting via structures

• US 6,507,083 B1
• Filed: 10/05/2000
• Issued: 01/14/2003
• Est. Priority Date: 10/05/2000
• Status: Expired due to Term

• Current Assignee: Pixim, Inc. (Sony Group Corp.)
• Original Assignee: Pixim, Inc. (Sony Group Corp.)
• Inventors: Tian, Hui
• Primary Examiner(s): Meier, Stephen D.
• Application Number:
  US09/680,087
• Time in Patent Office: 831 Days
• Field of Search: 257/432, 257/435, 257/436
• US Class Current: 257/432
• CPC Class Codes: H01L 27/14623 Optical shielding

Abstract

An image sensor has a light-shielding layer with openings corresponding to an array of light-sensing elements formed below on a substrate. Light-reflecting material is applied to form (e.g., vertical) via walls between each opening in the light-shielding layer and the corresponding light-sensing element. Light having a non-normal angle of incidence will reflect off the vertical light-reflecting via structures towards the light-sensing elements. As such, substantially all of the light that passes through an opening in the light-shielding layer will reach the light-sensing element, even light incident at relatively low angles, thereby reducing the problem of pixel vignetting associated with prior art image sensors. As a result, the image sensor has a greater and more uniform sensitivity across the entire sensor array.

Claims

1. An integrated sensor comprising:

one or more light-sensing elements formed on a substrate; and

a light-reflecting structure for each light-sensing element, configured within intervening structure above the substrate to reflect incident light towards the light-sensing element;

a light-shielding layer formed over the intervening structure and defining a transparent opening corresponding to each light-sensing element such that light passing through each opening in the light-shielding layer is reflected by a corresponding light-reflecting structure towards a corresponding light-sensing element.

2. The invention of claim 1, wherein the sensor comprises a plurality of light-sensing elements and a plurality of corresponding light-reflecting structures.

3. The invention of claim 1, wherein each light-reflecting structure is a vertical via structure formed within the intervening structure.

4. The invention of claim 1, wherein each light-reflecting structure is a non-vertical via structure formed within the intervening structure.

5. The invention of claim 1, wherein the intervening structure comprises a transparent material within each light-reflecting structure.

6. The invention of claim 5, wherein the intervening structure further comprises one or more layers of non-transparent material outside of the one or more light-reflecting structures.

7. The invention of claim 1, wherein

the sensor comprises a plurality of light-sensing elements and a plurality of corresponding light-reflecting structures;

each light-reflecting structure is a via structure formed within the intervening structure;

the intervening structure comprises a transparent material within each light-reflecting structure; and

the intervening structure further comprises one or more layers of non-transparent material outside of the one or more light-reflecting structures.