Novel hybrid integration method

Abstract

The invention discloses a novel hybrid integration method, which comprises the following steps of: assembling a mother board chip; assembling a daughter board chip; and assembling an integrated chip. The mother board chip comprises a mother board chip body, wherein the mother board chip body has a mother board chip metal area, a mother board chip vertical supporting assembly and a mother board chip waveguide area, and the mother board chip waveguide area comprises a coupling waveguide area used for vertical coupling. The daughter board chip comprises a daughter board chip body, wherein the daughter board chip body has a daughter board chip metal area, a daughter board chip vertical supporting assembly and a daughter board chip waveguide area, and the daughter board chip waveguide area comprises a coupling waveguide area. The daughter board chip is attached to the top end of the mother board chip in an inverted mode, the mother board chip vertical supporting assembly is attached to the daughter board chip vertical supporting assembly, the mother board chip coupling waveguide area is attached to or close to the daughter board chip coupling waveguide area, and the mother board chip metal area is fixedly connected with the daughter board chip metal area. According to the hybrid integration method, the alignment tolerance between the optical chips is increased, and the optical loss and the optical reflection are reduced.

Description

technical field [0001] The invention relates to the technical field of optical integration, in particular to a new hybrid integration method. Background technique [0002] In recent years, integrated optical circuits have developed rapidly. Integrating lasers, modulators, and detectors in optical fiber communications on a single chip can meet the development trend of miniaturization, low power consumption, and low cost. At present, integrated optical circuits can rely on many material systems. For example, active devices mainly come from indium phosphide, gallium arsenide, and gallium nitride, and passive devices mainly rely on silicon, silicon nitride, silicon oxide, aluminum nitride, and niobium. Lithium Oxide etc. Considering the wafer cost and mature processing technology, silicon has become the most promising material for integrated optical circuits. But silicon still can't meet all the needs of optical communication devices. For example, as a semiconductor material ...

AI Technical Summary

Problems solved by technology

[0004] However, the biggest problem of flip-chip integration at present is the coupling of light between different material systems.

Grating coupling (Grating coupling) cannot meet the working requirements of the entire C-band; mirror coupling (Mirror coupling) is difficult to process, and generally can only be produced at the end of the chip (Noriki A, Amano T, Shimura D, et al. Broadband and polarization- independent efficient vertical optical coupling with 45°mirror for optical I / O of Si photonics[J].Journal of Lightwave Technology,2016,34(3):978-984.); the coupling efficiency of direct docking coupling (Butt coupling) is limited on end face quality, end face reflection and 3D alignment error

Today's commercial Flip-chip platform can achieve alignment errors within 500nm in both horizontal directions through alignment marks, but alignment in the vertical direction is still a challenge, requiring high substrate thickness and uniformity of material etching. Moreover, different materials have different thermal expansion coefficients, and temperature changes will inevitably cause misalignment in the vertical direction of the optical docking part of the hybrid integrated device.

On the other hand, now more spot converters are used to enlarge the alignment spot, which is beneficial to direct docking to a certain extent, but there is always a gap between the end faces, which affects the coupling efficiency, and the three-dimensional alignment tolerance is not good. High, the theoretical optical coupling loss within the alignment error of ±1μm is -2.3dB (Theurer M, Moehrle M, Sigmund A, etal. Flip-chip integration of InP and SiN [J]. IEEE Photonics Technology Letters, 2019, 31 (3):273-276.)

In addition, how to reduce the light reflection of the end surface when the waveguide is directly connected is also a problem. Whether it is an etching interface or a cleavage surface, there will be a certain amount of end surface light reflected back to the active device, which will seriously affect the performance of the device. On-chip integrated optical isolator it's not easy either

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