Photodiode device with reducible space charge region

摘要

The photodiode device comprises a doped region (2) contiguous with a contact region (3) of the same conductivity type located at the substrate surface (1′), an appertaining anode or cathode connection (7, 11), a further contact region (5) of an opposite conductivity type at the substrate surface, and a further anode or cathode connection (8, 12). The contact region (3) is arranged at least on opposite sides of an active area of the substrate surface that covers the further contact region (5). A lateral pn junction (16) and an associated space charge region is formed at the substrate surface by a boundary of one of the contact regions, the boundary facing the other contact region. A field electrode (6) is arranged above the lateral pn junction, separated from the lateral pn junction by a dielectric material (10), and is provided with a further electrical connection (9, 13) separate from the anode and cathode connections. By the field electrode (6), the space charge region at the surface (1′) is reduced and the peripheral dark current of the photodiode decreases considerably.

主权项

1. A photodiode device, comprising:
a substrate of semiconductor material having a surface and an area of the surface that is entirely formed by the semiconductor material; a doped region of a first type of electrical conductivity in the substrate; a contact region of the first type of electrical conductivity at the surface, the contact region being contiguous with the doped region and provided with an anode or cathode connection; a further contact region of a second type of electrical conductivity that is opposite to the first type of electrical conductivity, the further contact region being arranged at the surface and provided with a further anode or cathode connection; the contact region being arranged at least on opposite sides of the area of the surface that is entirely formed by the semiconductor material of the substrate, this area covering the further contact region; a lateral pn junction being formed at the surface by a boundary of one of the contact regions, the boundary facing the other contact region; a field electrode being arranged above the lateral pn junction and being separated from the lateral pn junction by a dielectric material; and the field electrode being provided with a further electrical connection separate from the anode and cathode connections.