Double-sided annular Ge-based long-wave infrared and terahertz detector and preparation method

Abstract

The invention discloses a double-sided annular Ge-based long-wave infrared and terahertz detector and a preparation method. The detector comprises an upper layer and a lower layer, each layer consistsof an annular absorption region, a central barrier region, an annular absorption region electrode and a central barrier region electrode, wherein electrodes in the absorption regions and the barrierregions between the layers are respectively connected in series through ohmic contact. The preparation method comprises five steps of sequentially forming an upper absorption region, a lower absorption region, an upper electrode region, a lower electrode region, an upper and lower electrode series end on the high-resistance Ge substrate through photoetching, ion implantation and thermal evaporation technologies. The double-sided annular device structure effectively enhances incident photon absorption and photo-generated electron-hole pair generation efficiency, quantum efficiency is improved,the detection rate of a traditional BIB type photon detector is improved, and the double-sided annular device structure is compatible with the current semiconductor process technology.

Description

technical field [0001] The invention relates to an infrared / detector with a new structure and a preparation method based on the principle of BIB (blocking impurity band) impurity band absorption photoconductivity, especially suitable for the detection of long-wave infrared and terahertz light with a wavelength in the range of 40-300 microns. Background technique [0002] Infrared detection technology has important application requirements in weather forecasting, environmental monitoring, missile guidance, night vision imaging and other fields. In this regard, mainstream infrared detectors such as HgCdTe and InGaAs are the main ones, mainly responding to the 1-20 micron band. This type of device is based on the principle of semiconductor pn structure photovoltaic effect, therefore, the detector has a high responsivity and the device has a high operating temperature (liquid nitrogen), and the development is rapid. However, limited by the type of material, the response waveleng...

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Problems solved by technology

However, with the extension of the detection wavelength, most of the incident photons cannot be absorbed by the substrate material, resulting in a sharp decrease in the quantum efficiency of the device. Generally, the quantum efficiency of Ge-based BIB detectors is <40%. The flow mainly occurs in the depletion region between the absorption region and the blocking region, and the short depletion region is not conducive to the effective absorption and utilization of photons, which limits the quantum efficiency of the detector.

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