Back-Illuminated Single-Photon Avalanche Diode

A back-illuminated single-photon avalanche diode (SPAD), comprising:

• a sensor wafer having a back surface opposite a front surface, the sensor wafer comprising:
• a SPAD region configured to receive photons of light entering through the back surface of the sensor wafer;
• a deep trench isolation (DTI) region surrounding the SPAD region and extending from the front surface to the back surface of the sensor wafer;
• a lateral shield disposed adjacent the front surface of the sensor wafer, under at least a portion of the SPAD region, and configured to reflect photons of light exiting the SPAD region back toward the SPAD region;
• and
• a contact disposed on the front surface of the sensor wafer, the contact electrically connected to the lateral shield.

A device, comprising:

• a sensor wafer having a back surface opposite a front surface, the sensor wafer comprising,
• an array of back-illuminated single-photon avalanche diodes (SPADs) including,
• a SPAD region having an anode region configured to receive photons of light entering through the back surface of the sensor wafer;
• a deep trench isolation (DTI) region surrounding the SPAD region and extending from the front surface to the back surface of the sensor wafer;
• a pinning layer on a side of the DTI region adjacent the SPAD region;
• and
• a contact disposed on the front surface of the sensor wafer;
• wherein,
• a voltage applied to the contact applies a bias voltage to the pinning layer.