Back irradiation arsenic indium table face line array or face array detector chip and its making technology

Abstract

The present invention discloses a back-irradiating indium gallium arsenic micro-table-board detector chip and the preparation technique thereof, the preparation technique comprises etching on the p-InGaAs / p-InP / i-InGaAs / n-InP epitaxial slice to form the p-InGaAs / p-InP / i-InGaAs micro-table-board, the thickness of the InGaAs absorption layer is designed to 1.1um to 1.5um, the doping concentration is 3-5*10<16>cm<-3>, the +SiNx passivating film is vulcanized and the annealing technique is leaded in, and the purposes of effectively reducing the combination of surface and side surface, reducing the density of interfacial state and increasing the detectivity and homogeneity of the device, the leading-out area of the p type electrode is grown with a layer of p-InGaAs electrode transition layer, the contact between the Ti / Pt / Au electrode grown by the evaporation of the electron beam and the p-InGaAs is excellent ohm contact, the small contact resistance increases the capability of the detector, at the same time the back-irradiating mode is adopted and the incident light will not be absorbed by the p-InGaAs of the p type electrode leading-out layer, the response ratio of the device is facilitated to be increased and the back low-temperature deposition ZnS reflection reducting coating can further increase the repose ratio and quantum efficiency of the device.

Description

technical field [0001] The invention relates to an infrared detection device and its manufacturing technology, specifically a back-illuminated indium gallium arsenide (InGaAs) micro-mesa line or area array detector chip and its preparation process, which is suitable for making high-uniformity long line or area arrays InGaAs micro-mesa focal plane detector. Background technique [0002] InGaAs short-wave infrared detectors can work at room temperature, and their performance is better than short-wave antimony-cadmium mercury (HgCdTe) detectors, so they have broad application prospects in military and civilian fields. InGaAs back-illuminated long-line array and area array detectors mostly use planar junction technology, but planar junction has some unavoidable disadvantages: complex diffusion process, enlarged photosensitive surface and zinc (Zn) diffusion will be in the indium phosphide (InP) layer. A large number of defects are caused, which limit the improvement of the perf...

AI Technical Summary

Problems solved by technology

InGaAs back-illuminated long-line array and area array detectors mostly use planar junction technology, but planar junction has some unavoidable disadvantages: complex diffusion process, enlarged photosensitive surface and zinc (Zn) diffusion will be in the indium phosphide (InP) layer. A large number of defects are caused, which limit the improvement of the performance of InGaAs detectors

The mesa-type indium gallium arsenide detector is to etch the p-type indium phosphide / indium gallium arsenide (p-InP / InGaAs) in the epitaxial material into a mesa. The advantage of this structure is that the process is relatively simple, and the disadvantage is that the side and surface Exposure will introduce a large number of interface states, which will limit the improvement of the uniformity of long line array and large area array devices, and the passivation film (such as ZnS, SiO 2 etc.) and process, it is difficult to obtain a device with high uniformity, which will affect the imaging quality of the device

In addition, it is also a difficult problem to reliably realize the extraction of ohmic contact electrodes on the p-InP cap layer. A p-InGaAs electrode transition layer is added on the p-InP layer to make the Ti / Pt / Au electrodes grown by electron beam evaporation Realizing the ohmic contact under the condition of annealing can solve the problem of P-type ohmic contact preparation process, application number: 200610118770.1), but under the positive irradiation structure, p-InGaAs will absorb the incident light, which reduces the responsivity and quantum efficiency of the device

Images