A key improvement is within the silicon photo-multiplier (SiPM) light receiving integrated circuits which have light-receiving cells controlled by transistors.
The new chips have smaller transistor modules, replace buffer layers protecting the transistors with newly-developed insulating trenches between the transistors and the light-receiving cells (diagram right).
To recover sensitivity lost in using smaller transistors, a high-withstand voltage section has been added to raise the voltage input to the light-receivers.
