Multi-photodiode pixel cell

US10903260B2 · kind B2 · utility

Assignee

• Facebook Technologies, LLC · US

Inventors

• Song Chen · Tangxia, CN
• Xinqiao Liu · Bellevue, US

Key dates

• Filing date: Jun 7, 2019
• Grant date: Jan 26, 2021
• Expiry date: Jun 7, 2039

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/812

Abstract

In one example, an apparatus comprises: a semiconductor substrate including a front side surface, a first photodiode to generate a first charge, a second photodiode to generate a second charge, a barrier layer between the first photodiode and the second photodiode and configured to control flow of the second charge from the second photodiode to the first photodiode, and a drain region to store the first charge and at least a first part of the second charge. The apparatus further comprises a gate on the front side surface over a first channel region between the first photodiode and the drain region to control the flow of the first charge and the at least the first part of the second charge to the drain region, and a second channel region to conduct at least a second part of the second charge away from the barrier layer when the second photodiode saturates.