SOI-based SiGe double-heterojunction photosensitive transistor detector

Abstract

The invention discloses an SOI-based SiGe double-heterojunction photosensitive transistor detector. An SOI substrate is adopted to replace a Si substrate. The detector comprises an SOI substrate whichis composed of a lower Si layer and a SiO2 layer. A Si secondary collector region, a Si collector region, a SiGe base region and a polycrystalline Si emitter region are sequentially prepared on the SOI substrate. Due to the refractive index difference generated by different refractive indexes of the Si material and the SiO2 material, a reflecting mirror can be formed on the Si / SiO2 interface, incident light can be reflected and absorbed again after reaching the Si / SiO2 interface in the SOI substrate, and the absorption efficiency is improved; in addition, due to the existence of the SiO2 layer in the SOI substrate, slow carriers generated in the lower Si layer of the substrate can be isolated, and the parasitic capacitance of the device is reduced, so that the working speed is increased.The photoelectric detector is manufactured on the SOI substrate, so that high-speed and high-efficiency optical detection can be realized.

Description

technical field [0001] The present invention relates to the technical field of semiconductor optoelectronics, in particular to an SOI-based SiGe double heterojunction phototransistor detector (HPT) that takes into account both responsivity and response speed, which can relieve the light absorption efficiency and The contradiction between working speed, while achieving high-speed and efficient light detection. Background technique [0002] The rapid development of modern optical communication requires that the optical communication network must have greater information transmission capacity and faster information processing speed, and the requirements for integrated circuit integration are getting higher and higher. Traditional electrical interconnection technology has become the bottleneck of high-speed data communication. . Optical interconnection technology has become a key technology to be solved urgently. Therefore, silicon-based photonic technologies suitable for opti...

AI Technical Summary

Problems solved by technology

In 2013, Taiwan reported a SiGe / Si HPT detector based on a 0.18μm BiCMOS process, which achieved a responsivity of up to 75A / W for light absorption at 750nm. However, due to the use of photogenerated carriers in the substrate, its frequency characteristics Poor, slow device operation

It can be seen that the responsivity and response speed of the current vertical structure Si-based photodetector still need to be improved, and there is a contradiction in the optimization of the responsivity and working speed of the phototransistor. To obtain a high responsivity, it is necessary to increase the thickness of the absorption region Improve the absorption efficiency of light, but this will increase the transit time of photo-generated carriers, thereby reducing the working speed of the device, and the influence of photo-generated carriers in the substrate is also a factor that cannot be ignored

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