DOPANT CONFIGURATION IN IMAGE SENSOR PIXELS

摘要

An image sensor pixel including a photodiode includes a first dopant region disposed within a semiconductor layer and a second dopant region disposed above the first dopant region and within the semiconductor layer. The second dopant region contacts the first dopant region and the second dopant region is of an opposite majority charge carrier type as the first dopant region. A third dopant region is disposed above the first dopant region and within the semiconductor layer. The third dopant region is of a same majority charge carrier type as the second dopant region but has a greater concentration of free charge carriers than the second dopant region. A transfer gate is positioned to transfer photogenerated charge from the photodiode. The second dopant region extends closer to an edge of the transfer gate than the third dopant region.

主权项

1. An image sensor pixel comprising:
a photodiode including a first dopant region disposed within a semiconductor layer; a second dopant region disposed above the first dopant region and within the semiconductor layer, wherein the second dopant region contacts the first dopant region, and wherein the second dopant region is of an opposite majority charge carrier type as the first dopant region; a third dopant region disposed above the first dopant region and within the semiconductor layer, wherein the third dopant region contacts the first dopant region and the second dopant region, and wherein the third dopant region is of a same majority charge carrier type as the second dopant region and has a greater concentration of free charge carriers than the second dopant region; and a transfer gate positioned to transfer photogenerated charge from the photodiode, wherein the second dopant region extends closer to an edge of the transfer gate than the third dopant region.