Planar indium gallium arsenic photosensitive chip with improved surface passivation and preparation method thereof

Abstract

The invention discloses a planar indium gallium arsenic light-sensitive chip with surface passivation improved and a manufacturing method. According to the structure of the planar indium gallium arsenic light-sensitive chip, an N-type InP layer, an indium gallium arsenic intrinsic absorption layer, an N-type InP cap layer, a SiNx passivation layer, a P-electrode and a thickened electrode (8) are grown on a semi-insulating InP substrate in sequence. The manufacturing process is improved on the basis of an original process, and comprises removal and vulcanization of a diffusion mask and silicon nitride passive film growing through an inductive coupling plasma chemical vapor deposition (ICPCVD) technology. The planar indium gallium arsenic light-sensitive chip with surface passivation improved and the manufacturing method have the advantages the passivation layer of the chip is even in structure; the surface state density of a device is effectively reduced, and the surface can be prevented from being oxidized again through a vulcanization film formed on the surface; damage of the process to the surface of materials is small, the film is compact and is in stress fit with the substrate, the element bonding state is good, and the passivaition effect is excellent.

Description

technical field [0001] The invention relates to the preparation technology of infrared detection devices, specifically a planar indium gallium arsenic photosensitive chip with improved surface passivation effect and its preparation method, which is suitable for preparing planar indium gallium arsenic detectors with high sensitivity and high reliability . Background technique [0002] InGaAs short-wave infrared detectors can achieve good performance at room temperature, which makes them have broad application prospects in civil, military and aerospace fields. Because the planar process brings lower damage to the preparation of the device, this makes the planar device have relatively excellent performance, and has strong competitiveness in realizing high performance, miniaturization, and low power consumption of the system. [0003] The cross-sectional structure of the planar InGaAs detector chip is shown in the attached figure 1 As shown, it consists of InP substrate 1, N-t...

AI Technical Summary

Problems solved by technology

[0010] In the manufacturing process of the existing planar InGaAs detector chip, the epitaxial material not only has to be exposed to the air, but also has to go through high-temperature processes such as diffusion. On the one hand, the surface passivation effect of the silicon nitride diffusion mask will be reduced. On the other hand, the InP surface exposed by the mask window will also be severely oxidized

In addition, in the process of depositing silicon nitride passivation film, the plasma generated by plasma enhanced chemical vapor deposition (PECVD) will cause relatively large damage to the surface of the epitaxial material

These problems in the process limit the improvement of the dark current performance of the detector, so it is necessary to improve and innovate the process to improve the performance of the detector

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