Avalanche photodiode

An avalanche photodiode for detecting radiation, comprising:

• a) a semiconductor substrate having a top side and a bottom side opposite said top side, wherein the semiconductor substrate is doped according to a first doping type,
• b) an upper diode layer which is disposed in the semiconductor substrate on the top side, is doped according to a second doping type and is contactable, wherein the second doping type is opposed to the first doping type,
• c) a laterally restricted lower diode layer which is disposed in the semiconductor substrate between the upper diode layer and the bottom side of the semiconductor substrate and is doped according to the first doping type,
• d) an avalanche region which extends below the upper diode layer, and is adapted to undergo a radiation-generated avalanche breakdown when triggered by the radiation to be detected,
• e) a contacting layer which is disposed on the bottom side of the semiconductor substrate and is doped according to the first doping type,
• f) a laterally restricted quenching resistance layer which is disposed in the semiconductor substrate between the lower diode layer and the contacting layer and is doped according to the first doping type, wherein the quenching resistance layer is adapted to quench the radiation-generated avalanche breakdown in the avalanche region, and
• g) a depletion electrode which is disposed at least partially in a lateral manner with respect to the laterally restricted lower diode layer and is doped according to the second doping type,
• wherein the depletion electrode is adapted to deplete the semiconductor substrate laterally next to the laterally restricted lower diode layer, and the quenching resistance layer of the lower diode layer is shielded from the depletion electrode such that the quenching resistance layer is not depleted or is only partially depleted, and
• wherein the upper diode layer and the contacting layer
• i) extend in a lateral direction without interruption over an entire width of the avalanche photodiode and
• ii) are laterally unstructured.

An avalanche photodiode for detecting radiation, comprising:

• a) a semiconductor substrate having a top side and a bottom side opposite said top side, wherein the semiconductor substrate is doped according to a first doping type,
• b) an upper diode layer which is disposed in the semiconductor substrate on the top side, is doped according to a second doping type and is contactable, wherein the second doping type is opposed to the first doping type,
• c) a laterally restricted lower diode layer which is disposed in the semiconductor substrate between the upper diode layer and the bottom side of the semiconductor substrate and is doped according to the first doping type,
• d) an avalanche region which extends below the upper diode layer, and is adapted to undergo a radiation-generated avalanche breakdown when triggered by the radiation to be detected,
• e) a contacting layer which is disposed on the bottom side of the semiconductor substrate and is doped according to the first doping type,
• f) a laterally restricted quenching resistance layer which is disposed in the semiconductor substrate between the lower diode layer and the contacting layer and is doped according to the first doping type, wherein the quenching resistance layer is adapted to quench the radiation-generated avalanche breakdown in the avalanche region, and
• g) a depletion electrode which is disposed at least partially in a lateral manner with respect to the laterally restricted lower diode layer and is doped according to the second doping type,
• wherein:
• (i) the depletion electrode is adapted to deplete the semiconductor substrate laterally next to the laterally restricted lower diode layer, (ii) the quenching resistance layer of the lower diode layer is shielded from the depletion electrode such that the quenching resistance layer is not depleted or is only partially depleted, and (iii) provided in the semiconductor substrate laterally next to the quenching resistance layer is a doped region, in which the semiconductor substrate is doped according to the second doping type.

An avalanche radiation detector which comprises a plurality of avalanche photodiodes for detecting radiation, said avalanche photodiodes comprising:

• a) a semiconductor substrate having a top side and a bottom side opposite said top side, wherein the semiconductor substrate is doped according to a first doping type,
• b) an upper diode layer which is disposed in the semiconductor substrate on the top side, is doped according to a second doping type and is contactable, wherein the second doping type is opposed to the first doping type,
• c) a laterally restricted lower diode layer which is disposed in the semiconductor substrate between the upper diode layer and the bottom side of the semiconductor substrate and is doped according to the first doping type,
• d) an avalanche region which extends below the upper diode layer, and is adapted to undergo a radiation-generated avalanche breakdown when triggered by the radiation to be detected,
• e) a contacting layer which is disposed on the bottom side of the semiconductor substrate and is doped according to the first doping type,
• f) a laterally restricted quenching resistance layer which is disposed in the semiconductor substrate between the lower diode layer and the contacting layer and is doped according to the first doping type, wherein the quenching resistance layer is adapted to quench the radiation-generated avalanche breakdown in the avalanche region, and
• g) a depletion electrode which is disposed at least partially in a lateral manner with respect to the laterally restricted lower diode layer and is doped according to the second doping type,
• wherein:
• (i) the depletion electrode is adapted to deplete the semiconductor substrate laterally next to the laterally restricted lower diode layer, (ii) the quenching resistance layer of the lower diode layer is shielded from the depletion electrode such that the quenching resistance layer is not depleted or is only partially depleted, (iii) individual avalanche photodiodes are connected in parallel with a common amplifier, (iv) the upper diode layer of the individual avalanche photodiodes extends in a lateral direction over several adjacent avalanche photodiodes, (v) the lower diode layer of the individual avalanche photodiodes is interrupted in each case between the adjacent avalanche photodiodes and comprises an intermediate space, and (vi) the upper diode layer depletes the semiconductor substrate in the intermediate space between the adjacent avalanche photodiodes and thereby electrically isolates the adjacent avalanche photodiodes from each other.

An avalanche radiation detector which comprises a plurality of avalanche photodiodes for detecting radiation, said avalanche photodiodes comprising:

• a) a semiconductor substrate having a top side and a bottom side opposite said top side, wherein the semiconductor substrate is doped according to a first doping type,
• b) an upper diode layer which is disposed in the semiconductor substrate on the top side, is doped according to a second doping type and is contactable, wherein the second doping type is opposed to the first doping type,
• c) a laterally restricted lower diode layer which is disposed in the semiconductor substrate between the upper diode layer and the bottom side of the semiconductor substrate and is doped according to the first doping type,
• d) an avalanche region which extends below the upper diode layer, and is adapted to undergo a radiation-generated avalanche breakdown when triggered by the radiation to be detected,
• e) a contacting layer which is disposed on the bottom side of the semiconductor substrate and is doped according to the first doping type,
• f) a laterally restricted quenching resistance layer which is disposed in the semiconductor substrate between the lower diode layer and the contacting layer and is doped according to the first doping type, wherein the quenching resistance layer is adapted to quench the radiation-generated avalanche breakdown in the avalanche region, and
• g) a depletion electrode which is disposed at least partially in a lateral manner with respect to the laterally restricted lower diode layer and is doped according to the second doping type,
• wherein:
• (i) the depletion electrode is adapted to deplete the semiconductor substrate laterally next to the laterally restricted lower diode laver, (ii) the quenching resistance layer of the lower diode layer is shielded from the depletion electrode such that the quenching resistance layer is not depleted or is only partially depleted, (iii) the depletion electrodes of individual avalanche photodiodes are separated in each case from the upper diode layer, (iv) the depletion electrodes are disposed in each case in the intermediate spaces between the adjacent avalanche photodiodes, (v) the depletion electrodes are jointly connected to a voltage source, and (vi) the upper diode layers of the adjacent avalanche photodiodes are connected to each other in each case by a line which bridges the intermediate space between the adjacent avalanche photodiodes.