阅读说明：本技术 一种含稀氮化合物的红外探测器外延片 (Infrared detector epitaxial wafer containing rare nitrogen compound ) 是由 黄珊珊 黄辉廉 丁杰 杨文奕 于 2020-04-29 设计创作，主要内容包括：本发明公开了一种含稀氮化合物的红外探测器外延片,包括InP衬底,在所述InP衬底上按照层状叠加结构依次设置有n型InP缓冲层、本征GaInNAs吸收层、p型InP层、p型InGaAs欧姆接触层。本发明通过引入与InP衬底相匹配的稀氮化合物GaInNAs(即本征GaInNAs吸收层)获得延伸波长且延伸波长可调节的红外探测器外延片,满足对波长向长波方向扩展红外探测器需求。(The invention discloses an infrared detector epitaxial wafer containing a rare nitrogen compound, which comprises an InP substrate, wherein an n-type InP buffer layer, an intrinsic GaInNAs absorption layer, a p-type InP layer and a p-type InGaAs ohmic contact layer are sequentially arranged on the InP substrate according to a layered stack structure. The invention obtains the extension wavelength and the extension wavelength of the infrared detector epitaxial wafer can be adjusted by introducing the rare nitrogen compound GaInNAs (namely the intrinsic GaInNAs absorption layer) matched with the InP substrate, thereby meeting the requirement of extending the infrared detector to the long wave direction.)

1. An infrared detector epitaxial wafer containing a rare-nitrogen compound comprises an InP substrate, and is characterized in that: an n-type InP buffer layer, an intrinsic GaInNAs absorption layer, a p-type InP layer and a p-type InGaAs ohmic contact layer are sequentially arranged on the InP substrate according to a layered stack structure.

2. An infrared detector epitaxial wafer containing a rare nitrogen compound according to claim 1, characterized in that: the thickness of the n-type InP buffer layer is 500nm, and the doping concentration of the n-type InP buffer layer is 2-6 e18/cm³。

3. An infrared detector epitaxial wafer containing a rare nitrogen compound according to claim 1, characterized in that: the intrinsic GaInNAs absorption layer can enable the band gap of the GaInNAs material to reach 0.41-0.62 eV by adjusting the In component and the N component of the intrinsic GaInNAs absorption layer, and keeps lattice matching with an InP substrate, and the cut-off absorption wavelength of a corresponding device can reach 2-3 μm.

4. An infrared detector epitaxial wafer containing a rare nitrogen compound according to claim 1 or 3, characterized in that: the thickness of the intrinsic GaInNAs absorption layer is 1000-3000 nm.

5. An infrared detector epitaxial wafer containing a rare nitrogen compound according to claim 1, characterized in that: the thickness of the p-type InP layer is 200-500 nm, and the doping concentration is 0.5-1.5 e18/cm³。

6. An infrared detector epitaxial wafer containing a rare nitrogen compound according to claim 1, characterized in that: the thickness of the p-type InGaAs ohmic contact layer is 30-70 nm, and the doping concentration of the p-type InGaAs ohmic contact layer is 5e18/cm³And the p-type InGaAs ohmic contact layer is lattice-matched with the InP substrate.

Technical Field

The invention relates to the technical field of semiconductor lasers, in particular to an infrared detector epitaxial wafer containing a rare nitrogen compound.

Background

With the development of aerospace remote sensing technology, infrared detectors are widely applied to weather and meteorological prediction, satellite-to-ground resource exploration and monitoring, and spectral analysis of surface feature landscapes and crops; in the civil field, infrared flaw detection and infrared temperature measurement are widely applied to production control at present; the infrared night vision and infrared alarm system plays a significant role in transportation and security; the infrared imaging technology greatly improves the medical level. Therefore, 1-3 μm is an important infrared band, and the infrared detector of the band has very important research significance.

InP-based PIN-type InGaAs infrared detectors are excellent representatives of the detectors. The InGaAs and the III-V group substrate are well matched, so that a high-quality epitaxial structure can be manufactured; the mature growth technology makes it easier to prepare than HgCdTe; the InP-based PIN type InGaAs infrared detector has high internal quantum efficiency and extremely small dark current in the working wavelength range; can continuously work at room temperature, and reduces the requirement on a refrigerator. However, the wavelength cutoff of the InGaAs detector matched with the InP substrate is about 1.7 μm, and In order to expand the wavelength cutoff of the InGaAs detector toward the long wavelength direction, i.e., to fabricate an InGaAs detector with extended wavelength, and to expand the application range of the detector, the In component In the InGaAs material needs to be increased, so that the forbidden bandwidth of the material is correspondingly reduced. For example, In_xGa_1-xThe extension of the cutoff wavelength of the As detector from 1.7 μm to 2.4 μm requires an increase In the In composition x from 0.53 to about 0.8, which results In a large lattice mismatch between the InGaAs and InP substrates of about + 1.85%. To solve this problem, a lattice graded buffer layer up to several μm in thickness has to be introduced. This results in an extension of the epitaxial growth time by at least 30% and a considerable increase in the source consumption, which directly increases the material and equipment costs of such products. In addition, due to the introduction of the buffer layer, lattice difference can introduce mismatch stress in the epitaxial process, the generation of the mismatch stress causes the increase of defects and dislocations in materials, and threading dislocations can directly enter the absorption layer, so that the increase of dark current of the device is directly caused, and the performance of the device is seriously weakened.

The rare nitrogen compound GaInNAs can enable the optical band gap of the GaInNAs to reach 0.2-0.73 eV by adjusting the components of In and N, and is In lattice match with an InP substrate. The GaInNAs material can keep the lattice constant unchanged and simultaneously realize continuous adjustment of band gap. The main reason for this is that the band gap is abnormally red-shifted when a small amount of N (10% or less) is doped into the InGaAs material to reduce the lattice constant. And after In element is doped into GaAs, the material can be reduced In band gap while the lattice constant is increased. Therefore, if the two elements are incorporated into GaAs in a proper proportion, the reduction of the band gap can be realized while the device performance is ensured by keeping the lattice constants of GaInNAs and InP basically matched, and the device is suitable for the requirement of long-wavelength response, and the cut-off response wavelength of the device can extend from 1.7 μm to 2-3 μm.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of the prior art, provides an infrared detector epitaxial wafer containing a dilute nitrogen compound, obtains an infrared detector epitaxial wafer with an extended wavelength and an adjustable extended wavelength by introducing the dilute nitrogen compound GaInNAs (namely an intrinsic GaInNAs absorption layer) matched with an InP substrate, and meets the requirement of expanding the infrared detector from the wavelength to the long-wave direction.

In order to achieve the purpose, the technical scheme provided by the invention is as follows: an infrared detector epitaxial wafer containing a rare-nitrogen compound comprises an InP substrate, wherein an n-type InP buffer layer, an intrinsic GaInNAs absorption layer, a p-type InP layer and a p-type InGaAs ohmic contact layer are sequentially arranged on the InP substrate according to a layered stack structure.

Further, the thickness of the n-type InP buffer layer is 500nm, and the doping concentration of the n-type InP buffer layer is 2-6 e18/cm³。

Furthermore, the intrinsic GaInNAs absorption layer can enable the band gap of the GaInNAs material to reach 0.41-0.62 eV by adjusting the In component and the N component of the intrinsic GaInNAs absorption layer, and keeps lattice matching with the InP substrate, and the cut-off absorption wavelength of a corresponding device can reach 2-3 μm.

Furthermore, the thickness of the intrinsic GaInNAs absorption layer is 1000-3000 nm.

Further, the thickness of the p-type InP layer is 200-500 nm, and the doping concentration is 0.5-1.5 e18/cm³。

Further, the thickness of the p-type InGaAs ohmic contact layer is 30-70 nm, and the doping concentration of the p-type InGaAs ohmic contact layer is 5e18/cm³Said p isThe type InGaAs ohmic contact layer is lattice-matched to the InP substrate.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the expansion of the cutoff wavelength of the detector increases the application range of the detector and promotes the development of space remote sensing.

2. And a rare nitrogen compound GaInNAs (namely an intrinsic GaInNAs absorption layer) matched with the lattice of the InP substrate is introduced, so that the material quality is high, the wavelength is extended, the defects caused by large lattice mismatch are avoided, and the performance of the device is ensured.

3. The chip and the back-end process are matched with the original InGaAs infrared detector, a new process does not need to be developed, and the research and development and production cost is saved.

4. The cut-off wavelength of the detector can be changed according to actual needs by adjusting In and N components.

Drawings

Fig. 1 is a schematic structural diagram of an infrared detector epitaxial wafer according to the present invention.

Detailed Description

The present invention will be further described with reference to the following specific examples.

As shown in fig. 1, the infrared detector epitaxial wafer containing a rare-nitrogen compound provided in this embodiment includes an InP substrate 1, and an n-type InP buffer layer 2, an intrinsic GaInNAs absorption layer 3, a p-type InP layer 4, and a p-type InGaAs ohmic contact layer 5 are sequentially disposed on the InP substrate 1.

The n-type InP buffer layer 2 has a thickness of about 500nm and a doping concentration of 2-6 e18/cm³。

The intrinsic GaInNAs absorption layer 3 enables the band gap of a GaInNAs material to reach 0.41-0.62 eV by adjusting the In component and the N component of the intrinsic GaInNAs absorption layer, keeps lattice matching with the InP substrate 1, enables the cut-off absorption wavelength of a corresponding device to reach 2-3 mu m, and enables the thickness of the intrinsic GaInNAs absorption layer 3 to be 1000-3000 nm.

The thickness of the p-type InP layer 4 is about 200-500 nm, and the doping concentration is 0.5-1.5 e18/cm³。

The thickness of the p-type InGaAs ohmic contact layer 5 is about 30-70 nm, and the doping is performedThe impurity concentration is about 5e18/cm³The p-type InGaAs ohmic contact layer 5 is lattice-matched to the InP substrate 1.

The following is a specific process for preparing the above infrared detector epitaxial wafer containing a dilute nitrogen compound in this example, and the following conditions are:

firstly, a 2-inch or 3-inch InP single crystal wafer is taken as a substrate, and then an n-type InP buffer layer 2, an intrinsic GaInNAs absorption layer 3, a p-type InP layer 4 and a p-type InGaAs ohmic contact layer 5 are sequentially grown on the upper surface of an InP substrate 1 by adopting a Metal Organic Chemical Vapor Deposition (MOCVD) technology or a Molecular Beam Epitaxy (MBE) technology, so that the preparation of the infrared detector epitaxial wafer containing the dilute nitrogen compound can be completed.

In summary, the invention introduces the rare nitrogen compound absorption layer (i.e. intrinsic GaInNAs absorption layer) which is lattice-matched with the InP substrate, the material quality is high, the defect caused by large lattice mismatch is avoided while the wavelength is extended, the performance of the device is ensured, the cut-off wavelength of the detector can be changed according to the requirement by adjusting In and N components, the chip and the back-end process are matched with the original InGaAs infrared detector, a new process and a production line do not need to be developed, the research and development and production cost are saved, the extended wavelength infrared detector with higher quality and wider application range can be obtained, and the invention is worthy of popularization.

The above-mentioned embodiments are merely preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, so that the changes in the shape and principle of the present invention should be covered within the protection scope of the present invention.