Silicon-based InGaAs PIN photoelectric detector based on heterogeneous integration and vertical optical coupling

Abstract

The invention discloses a silicon-based InGaAs PIN photoelectric detector based on heterogeneous integration and vertical optical coupling. The silicon-based InGaAs PIN photoelectric detector comprises a silicon-on-insulator (SOI) substrate, a vertical coupling grating, a benzocyclobutene (BCB) bonding layer, an anti-reflecting layer, a first conductivity type indium phosphide layer, an intrinsic InGaAs layer and a second conductivity type indium phosphide layer, wherein the vertical coupling grating is produced in top silicon of the SOI substrate, the BCB bonding layer is covered on the vertical coupling grating, the anti-reflecting layer is located above the BCB bonding layer, the first conductivity type indium phosphide layer is located above the anti-reflecting layer, the intrinsic InGaAs layer is located above the first conductivity type indium phosphide layer, the second conductivity type indium phosphide layer is located above the intrinsic InGaAs layer, the vertical coupling grating is produced by etching the top silicon of the SOI substrate, the etching depth is 70-110 nm, the grating period is 600-680 nm, and the refractive index of the anti-reflecting layer is between refractive indexes of the BCB bonding layer and the first conductivity type indium phosphide layer. According to the silicon-based InGaAs PIN photoelectric detector, by means of an adhesiveness bonding process, InP / InGaAs / InP stack material layers are adhered to the grating which is etched on the SOI substrate, so that light and the InP / InGaAs / InP layers are vertically coupled, and suitable designs and prioritization schemes are provided for specific applications of the silicon-based InGaAs PIN photoelectric detector.

Description

technical field [0001] The invention relates to a photodetector with a PIN structure, in particular to a photodetector with a PIN structure using a silicon-based InGaAs material based on heterogeneous integration and vertical optical coupling technology, and belongs to the field of semiconductor devices. Background technique [0002] Silicon photonics was proposed by Soref in the late 1980s, and has entered a period of rapid development in recent years. As a platform for optical integration, silicon has good light transmission, and due to the relatively high refractive index difference between silicon and silicon dioxide, waveguides with submicron-sized cross-sections and micron-scale bending radii can be realized, which is conducive to the realization of optical devices large-scale integration. Moreover, silicon-based optical integration technology is also compatible with CMOS technology. By applying high-quality and large-scale CMOS technology to integrate integrated circ...

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Problems solved by technology

The inventors of the present invention have found through in-depth research and analysis that although the latter separates the light absorption path from the propagation path of electron-hole pairs, thus avoiding the mutual constraint between the responsivity and the bandwidth limited by the transit time, it usually requires A very thin BCB bonding layer (usually <200nm) is used to achieve efficient coupling between the waveguide and the detector, and at such a thin bonding layer thickness, the planarization of the wafer surface pattern and the number of impurity particles will affect the The bonding yield has a great impact; in the vertical coupling method assisted by the grating coupler, the thickness of the BCB bonding layer is not required to be so thin, so the bonding process is relatively simple and the success rate is high, but it needs to be at high Balance between responsivity and high frequency response

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