US 12,261,233 B2
Photodetectors and photodetector arrays
Maxim Gureev, Lausanne (CH); Denis Sallin, Lausanne (CH); and Serguei Okhonin, Lausanne (CH)
Assigned to ActLight SA, Lausanne (CH)
Filed by ActLight SA, Lausanne (CH)
Filed on Jul. 25, 2023, as Appl. No. 18/358,817.
Application 18/358,817 is a continuation of application No. 16/933,159, filed on Jul. 20, 2020, granted, now 11,735,677.
Prior Publication US 2023/0378386 A1, Nov. 23, 2023
Int. Cl. H01L 25/18 (2023.01); G01J 1/42 (2006.01); H01L 27/146 (2006.01); H01L 31/0352 (2006.01); H01L 31/103 (2006.01)
CPC H01L 31/035272 (2013.01) [G01J 1/42 (2013.01); H01L 25/18 (2013.01); H01L 27/1463 (2013.01); H01L 27/14643 (2013.01); H01L 31/1037 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A photodetector device comprising:
a light absorbing region of doped semiconductor material bounded by upper, lower and side surfaces, the light absorbing region being configured to generate pairs of oppositely charged carriers in response to photon absorption;
an anode region composed of a highly doped p-type or n-type semiconductor material and arranged in contact with the light absorbing region;
a cathode region composed of a highly doped n-type or p-type semiconductor material of opposite type to the anode region and arranged in contact with the light absorbing region;
a potential barrier forming region composed of a highly doped n-type or p-type semiconductor material of opposite type to the anode region and arranged between the anode region and the cathode region in contact with the light absorbing region; and
a ground region composed of a highly doped p-type or n-type semiconductor material of the same types as the anode region and arranged in contact with the light absorbing region;
wherein a depletion region is created in the light absorbing region adjacent the anode region when the device is switched from a reverse bias to a forward bias for sensing, and carriers of appropriate positive or negative charge type generated in the light absorbing region in response to photon absorption are induced by the forward bias to drift towards the depletion region, wherein in response to the carriers reaching the depletion region their associated charges cause a current between the anode and ground regions to increase, such that a threshold number of the carriers arriving at the depletion region is sufficient to induce a further current to start to flow between the anode and cathode regions.