Growth method for buffering layer of expanding wavelength near-infrared detector

Abstract

The invention discloses a growth method for a buffering layer of an expanding wavelength near-infrared detector. The method comprises the following steps: adopting a metallic organic chemical vapor deposition process or a molecular beam epitaxy process for growing one of an In<x>Ga<1-x>As low temperature layer, an InAs<y>P<1-y> low temperature layer and an In<z>Al<1-z>As low temperature layer on an InP substrate at a first temperature; increasing the temperature of the InP substrate to a second temperature, and annealing the In<x>Ga<1-x>As low temperature layer, InAs<y>P<1-y> low temperature layer or In<z>Al<1-z>As low temperature layer; and growing one of an In<w>Ga<1-w>As component gradient layer, an InAs<w>P<1-w> component gradient layer and an In<w>Al<1-w>As component gradient layer at a third temperature, wherein the second temperature is higher than the first temperature and the third temperature is higher than the second temperature. According to the growth method, the thickness of the buffering layer can be reduced, the dislocation density can be reduced, and thus a detector with excellent high speed performance can be acquired.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a growth method for a buffer layer of an extended-wavelength near-infrared detector. Background technique [0002] In the near-infrared band of 1-3μm, InGaAs, InAsP and InAlAs are very important infrared detection materials. Compared with traditional HgCdTe materials and antimonide materials, they have higher electron mobility, good stability and radiation resistance. Lighting performance, and more mature material growth and device fabrication process technology. Taking InGaAs as an example, InGaAs devices have better performance under higher temperature and strong irradiation. Its band gap can vary between 0.35 and 1.43 eV, corresponding to the spectral wavelength range of 0.88 to 3.6 μm. It has been successfully applied in space Remote sensing and infrared imaging and other fields. In recent years, in the fields of space imaging (including earth remote sensing, atmo...

AI Technical Summary

Problems solved by technology

The advantage of the composition gradient method is that the dislocation density of the epitaxial layer can be reduced to a very low level, but the disadvantage is that a thicker buffer layer (up to 6 μm in thickness) needs to be grown, which is not conducive to improving the response frequency of the detector.

The advantage of the high and low temperature two-step method is that the buffer layer is thin, and the disadvantage is that the dislocation density of the epitaxial layer is high, which is not conducive to reducing the dark current of the device.

Therefore, the conventional epitaxial growth method will seriously affect the performance of the device.