Canon patent application: A new type of stacked sensor design

This is a new twist on stacked sensor, it seems Canon is working on where the entire top substrate is photoelectric conversion and the bottom substrate contains all the semiconductor electronics associated with the sensor.  This patent deals with designing such a sensor with an electronic (and I suppose meaning, global) shutter.

As a photoelectric conversion device, for example, used for an image sensor of a camera, there is proposed what is called a stack type photoelectric conversion device, in which a photoelectric conversion layer is stacked above a semiconductor substrate. 

Japanese Patent Application Laid-Open No. 2016-86407 discusses such a stack type photoelectric conversion device. In the photoelectric conversion device, an upper electrode shared by a plurality of pixels is located on the photoelectric conversion layer, and a pixel electrode and an auxiliary electrode are located under the photoelectric conversion layer. According to the discussion in Japanese Patent Application Laid-Open No. 2016-86407, the sensitivity of the photoelectric conversion layer can be adjusted by controlling a voltage applied to the auxiliary electrode. Furthermore, according to the illustration in FIG. 11 of Japanese Patent Application Laid-Open No. 2016-86407, the generation of signal electric charge in the photoelectric conversion layer can be prevented by controlling voltages applied to the upper electrode and the auxiliary electrode. Thus, according to the discussion in Japanese Patent Application Laid-Open No. 2016-86407, an electronic shutter operation can be implemented.

Looking at the diagram this sensor would be an significantly different than the more traditional sensors designed.  Whether or not this is practical and efficient enough in today's sensor environments, is another question that isn't really answered in this patent application.  This is very unlike any other stacked sensor design we have seen come out of Canon for quite some time.

Keep in mind that all patent applications may not bear fruit, but it gives us an idea on what Canon is looking at for future products and technologies.

US Patent Application 20180151608