US 9,812,482 B2
Frontside illuminated (FSI) image sensor with a reflector
Min-Feng Kao, Chiayi (TW); Dun-Nian Yaung, Taipei (TW); Jen-Cheng Liu, Hsin-Chu (TW); Jeng-Shyan Lin, Tainan (TW); Hsun-Ying Huang, Tainan (TW); and Tzu-Hsuan Hsu, Kaohsiung (TW)
Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (TW)
Filed on Dec. 28, 2015, as Appl. No. 14/980,225.
Prior Publication US 2017/0186796 A1, Jun. 29, 2017
Int. Cl. H01L 31/062 (2012.01); H01L 27/146 (2006.01)
CPC H01L 27/14629 (2013.01) [H01L 27/1469 (2013.01); H01L 27/14621 (2013.01); H01L 27/14634 (2013.01); H01L 27/14636 (2013.01); H01L 27/14645 (2013.01); H01L 27/14685 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An image sensor comprising:
a sensor device comprising:
a sensor substrate along a backside of the sensor device;
a photodetector buried in the sensor substrate;
a transistor over the sensor substrate, wherein the transistor comprises a gate electrode and the photodetector as a source/drain region; and
a sensor interconnect structure covering the sensor substrate, the transistor, and the photodetector, wherein the sensor interconnect structure is along a frontside of the sensor device, opposite the backside of the sensor device, wherein the sensor interconnect structure comprises a plurality of via layers and a plurality of interconnect layers alternatingly stacked with the via layers, and wherein a bottom one of the via layers is between and contacts the gate electrode and a bottom one of the interconnect layers;
a color filter covering the photodetector over the sensor interconnect structure;
a support device comprising:
a support substrate along a backside of the support device, and further arranged under and bonded to the sensor substrate;
a second transistor over and recessed within the support substrate;
a reflector arranged under the photodetector, between the sensor and support substrates, and configured to reflect incident radiation towards the photodetector; and
a support interconnect structure covering the second transistor and the support substrate, between the support and sensor substrates, wherein the support interconnect structure is along a frontside of the support device, opposite the backside of the support device, wherein the support interconnect structure comprises a plurality of second via layers and a plurality of second interconnect layers alternatingly stacked with the second via layers, and wherein a bottom one of the second via layers is between and contacts the second transistor and a bottom one of the second interconnect layers;
wherein the support device is bonded to the sensor device at an interface between the frontside of the support device and the backside of the sensor device.