Side-illuminated pin photodetector chip and manufacturing method thereof

Abstract

The invention discloses a lateral light incidence type PIN photoelectric detector chip and a manufacturing method thereof. The PIN photoelectric detector chip comprises a substrate, a buffer layer, an absorption layer, a transition layer, a top layer, a contact layer, composite passivation layers, a first protection layer, a negative electrode, a positive electrode, a doped active region and an antireflection film, wherein the substrate is provided with a light incidence surface; the antireflection film is formed on the light incidence surface; an inverted V-shaped corrosion groove is formed in the bottom of the substrate, opposite to the doped active region, and is provided with a first side wall and a second side wall; the first side wall and the bottom surface of the substrate form an angle of 45 degrees; the first protection layer is a polyimide protection layer with low dielectric constant; the contact layer, the top layer, the transition layer and the composite passivation layer at the absorption layer form a P-type table surface; the composite passivation layer at the buffer layer forms an N-type table surface; both the P-type table surface and the N-type table surface are concentric with the doped active region.

Description

technical field [0001] The invention relates to the field of optical communication transmission, in particular to a side incident light type PIN photodetector chip and a manufacturing method thereof. Background technique [0002] With the rapid development of optical communication technology, people have higher and higher requirements on the transmission rate of optical communication. At present, 10G optical network systems have been rolled out in large quantities, and the next-generation optical communication system will gradually develop into an optical network system dominated by 100G optical communication. However, as the core chip in the optical communication system, the PIN photodetector chip has higher and higher requirements on the receiving rate. Since there is no optical receiving chip with a single-chip receiving rate that can reach 100G, the current design of the usual 100G optical receiving chip is composed of an array chip composed of four PIN photodetector ch...

AI Technical Summary

Problems solved by technology

However, if figure 1 and figure 2 As shown, the current conventional PIN photodetector chip adopts a conventionally designed epitaxial wafer 100, and the photogenerated carriers generated after the PIN photodetector chip receives light have a longer drift time in the PN junction of the chip, and a larger diffusion source area 200 and planar structure design, resulting in relatively large chip capacitance and distribution parameters, resulting in the receiving rate of the PIN photodetector chip cannot reach 28G

In addition, the light-receiving surface of the current common photodetector chip is on the front or back of the chip, such as figure 1 The photosensitive surface in 300 and as figure 2 The photosensitive surface 400 in the chip cannot be directly coupled with the passive optical waveguide, so it cannot be used to form an optical receiving chip with a receiving rate of 100G

Images