Fabrication method of ge photodetector with lateral p-i-n structure

Abstract

The invention discloses a method for preparing a Ge photoelectric detector with a transverse p-i-n structure, and relates to the germanium photoelectric detector. The method comprises the steps of (1) carrying out epitaxial growth of a monocrystalline germanium layer on a substrate, growing a SiO2 covering layer on the monocrystalline germanium layer, (2) using a micro-electronics photolithography to etch an active area platform surface of a long and thin strip shape on the epitaxial monocrystalline germanium layer, (3) using the SiO2 covering layer on the monocrystalline germanium layer for masking, forming a doped p area and a doped n area on the two sides of the platform surface respectively through sidewise large-declination ion implantation, (4) carrying out thermal annealing after deposition of a metal Ni layer, forming NiGe contact electrodes and NiSi contact electrodes on the two sides of the platform surface and the bottom of the etched area through a self-alignment technology used in the forming process of NiGe and NiSi, and (5) leading out the device electrodes, and protecting a passivating layer. Therefore, the Ge photoelectric detector with the transverse p-i-n structure is obtained. The technology is simple, operability is high, and high application value is achieved.

Description

technical field [0001] The invention relates to a germanium photodetector, in particular to a preparation method of a lateral p-i-n structure Ge photodetector. Background technique [0002] Studies have shown that more than half of the power consumption in integrated circuit chips is concentrated in the interconnection of the chip, and the interconnection is also limited by the bandwidth of signal transmission. In the long run, it is an inevitable requirement for the further integration of chips to introduce optical interconnections instead of electrical interconnections inside the chip, and to use photons as carriers to achieve high-speed and low-power signal transmission. In silicon-based optical interconnection, the photodetector that converts optical signal into electrical signal is an important device to realize on-chip optical interconnection. The method of making a photodetector is to directly epitaxial germanium (Ge) material on silicon as an active region to prepar...

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Problems solved by technology

However, the Ge intrinsic region is also the absorption region of the vertically incident light signal, and the light absorption and the photogenerated carrier transition proceed in the same direction. The thinning of the intrinsic region will inevitably lead to insufficient light absorption at the same time, thus reducing the optical signal response of the device. Spend

The contradiction between high speed and high responsivity is an inherent defect of vertical incidence vertical p-i-n structure Ge photodetectors

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