A vertical integrated refrigeration type tellurium cadmium mercury detector assembly with accurate temperature control

Abstract

The application discloses a vertical integrated refrigeration type tellurium cadmium mercury detector assembly with accurate temperature control, which comprises, from bottom to top, a three-stage semiconductor refrigerator, epoxy glue, a manganese cobalt nickel oxygen thermistor, epoxy glue and a tellurium cadmium mercury detector. The manganese cobalt nickel oxygen thermistor comprises, from bottom to top, a sapphire substrate, a manganese cobalt nickel oxygen film and cadmium / gold composite electrodes on both sides of the thermistor film. The tellurium cadmium mercury detector comprises, from bottom to top, a sapphire substrate, epoxy glue, a tellurium cadmium mercury functional material, an anode oxidation layer, a ZnS anti-reflection layer and indium / gold composite electrodes on both sides of the tellurium cadmium mercury material. The detector assembly can accurately measure the real-time change of the detector temperature, effectively solves the temperature drift problem caused by attaching the thermistor to the side wall of the detector in the conventional process, makes accurate temperature control of the tellurium cadmium mercury detector possible, and greatly relieves the requirement for the temperature control accuracy of the detector in high-precision application scenarios.

Description

Technical Field

[0001] This invention relates to infrared detectors, specifically to a vertically integrated cooled mercury cadmium telluride detector assembly with precise temperature control and its preparation method. Background Technology

[0002] Mercury cadmium telluride (MCH) detectors have garnered significant attention in the infrared detection field due to their high responsivity, tunable response spectrum, and fast response speed. To improve responsivity and suppress intrinsic noise, MCH detectors operate at low temperatures. Cooling methods typically include liquid nitrogen cooling, Stirling refrigeration, and semiconductor cooling. Semiconductor cooling, in particular, offers advantages such as compact packaging, low power consumption, no vibration interference noise, and energy efficiency, making it a promising candidate for applications in civilian fields such as fire monitoring, train axle temperature detection, and spectral analysis.

[0003] In practical applications of semiconductor-cooled detectors, to control the detector at a set temperature and maintain a certain level of temperature control accuracy, a negative temperature coefficient (NTC) thermistor is typically mounted on the side wall of the detector for real-time temperature measurement. However, this mounting structure faces the following problems in high-precision temperature control applications: one side of the thermistor is in close contact with the mercury cadmium telluride (HCd) detector to sense the device's temperature, while the other side is exposed to the thermal radiation of the packaged casing to sense the casing's temperature. Ultimately, the equivalent temperature detected by the thermistor is the sum of these two temperatures. Moreover, as the operating time increases, the casing temperature gradually rises, causing the actual temperature detected by the thermistor to slowly increase. Due to the inaccurate temperature measurement by the thermistor, the semiconductor cooler experiences a so-called temperature drift phenomenon, which seriously affects the high-precision application of the HCd detector.

[0004] To address the aforementioned issues, this patent presents a vertically integrated cooled mercury cadmium telluride detector assembly with precise temperature control. Summary of the Invention

[0005] This invention proposes a vertically integrated cooled mercury cadmium telluride detector assembly structure with precise temperature control. It replaces the commercial thermistor used in conventional processes with a self-made manganese cobalt nickel oxide thin-film thermistor, and vertically integrates it with the mercury cadmium telluride detector and the semiconductor cooler to effectively avoid temperature disturbances in the tube shell and thus achieve precise temperature control.

[0006] The precisely temperature-controlled vertically integrated cooled mercury cadmium telluride detector of this invention is shown in the figure. Its key feature is that the structure consists of three parts: a three-stage semiconductor cooler 1, a manganese cobalt nickel-oxygen thermistor 2, and a mercury cadmium telluride detector 3. The specific structure and packaging include:

[0007] A three-stage semiconductor cooler 1 can provide low temperatures of -50°C and below, enabling the mercury cadmium telluride detector to operate within a suitable temperature range.

[0008] An epoxy adhesive 4 with a thickness of 1μm is used to bond a semiconductor cooler to a manganese cobalt nickel oxide thermistor.

[0009] 2. A manganese cobalt nickel oxide thermistor above a semiconductor cooler;

[0010] A mercury cadmium telluride detector 3;

[0011] An epoxy adhesive with a thickness of 1 μm is used to bond a manganese cobalt nickel oxide thermistor to a mercury cadmium telluride detector.

[0012] The structure of the manganese cobalt nickel-oxygen thermistor includes:

[0013] A double-polished transparent sapphire substrate 5, with a substrate thickness of 0.5mm;

[0014] A manganese cobalt nickel oxide thin film material 6 was prepared by the sol-gel method and has a thickness of 2 μm.

[0015] One-ohm contact electrode 7, the metal material of which is cadmium / gold grown by dual ion beam sputtering, with a thickness of 20nm / 300nm;

[0016] The mercury cadmium telluride detector structure includes:

[0017] A double-polished clear sapphire substrate 9, with a substrate thickness of 0.3mm;

[0018] An epoxy adhesive 10, 1 μm thick, is used to bond mercury cadmium telluride to a sapphire substrate.

[0019] A 12-layer cadmium telluride functional material layer 12 with a thickness of 10 μm on a sapphire substrate;

[0020] Anodized layers 11 on the upper and lower surfaces of mercury cadmium telluride;

[0021] ZnS anti-reflection layer 13 above a mercury cadmium telluride oxide layer;

[0022] A composite ohmic contact electrode of indium / gold 14 with a thickness of 20nm / 600nm is placed on the surface of a mercury cadmium telluride material.

[0023] Among them, the manganese cobalt nickel oxygen thermistor has a high resistivity and a thin film thickness. In order to reduce the total resistance, the shape is designed as a rectangular coil and the electrodes are located at both ends of the resistor.

[0024] The mercury cadmium telluride detector is located directly above the manganese cobalt nickel oxygen thermistor, and the centers of the two coincide. The mercury cadmium telluride detector completely covers the rectangular coil area of ​​the thermistor.

[0025] The greatest advantage of this invention is the design of a novel, precisely temperature-controlled, vertically integrated, cooled mercury cadmium telluride (HCd) detector assembly structure. A thin-film thermistor is tightly bonded between the HCd detector and the semiconductor cooler; this packaging structure is difficult to achieve with commercially available bulk thermistors. This vertically integrated packaging not only accurately measures the detector's real-time temperature changes but, more importantly, effectively avoids the influence of heat radiation from the shell sidewalls and environmental disturbances on the thermistor. This makes precise temperature control of the HCd detector possible, greatly alleviating the requirements for detector temperature control accuracy in high-precision applications. Attached Figure Description

[0026] Figure 1 A structural diagram of a vertically integrated cooled mercury cadmium telluride detector assembly with precise temperature control;

[0027] In the diagram: 1. Three-stage semiconductor cooler;

[0028] 2. Manganese cobalt nickel oxide thermistor;

[0029] 3. Mercury cadmium telluride detector;

[0030] Figure 2 A structural diagram of a precisely temperature-controlled, vertically integrated, cooled mercury cadmium telluride detector assembly.

[0031] In the diagram: 4. Epoxy adhesive;

[0032] 5. Double-polished transparent sapphire substrate;

[0033] 6. Manganese cobalt nickel oxide thin film materials;

[0034] 7. Composite ohmic contact electrode cadmium / gold;

[0035] 8. Epoxy adhesive;

[0036] 9. Double-polished transparent sapphire substrate;

[0037] 10. Epoxy adhesive;

[0038] 11. Anodized layer;

[0039] 12. Mercury cadmium telluride functional materials;

[0040] 13. ZnS antireflective layer;

[0041] 14. Composite ohmic contact electrode indium / gold.

[0042] Figure 3 Top view of the manganese cobalt nickel oxygen thermistor in the component. Detailed Implementation

[0043] The following describes in detail the specific embodiments of the present invention using the structure of a vertically integrated cooled mercury cadmium telluride detector assembly:

[0044] 1. Process mercury cadmium telluride (HCM) materials to 10 μm using conventional methods;

[0045] 2. The mercury cadmium telluride sheet is chemically etched and then anodized.

[0046] 3. Apply the treated mercury cadmium telluride flakes to the sapphire substrate using epoxy adhesive;

[0047] 4. After photolithography, argon ion etching is used to define the shape of the photosensitive surface of the device;

[0048] 5. After treating the device surface with HF acid etching solution, perform anodizing treatment again;

[0049] 6. Photolithography and deposition of composite ohmic contact electrodes in indium / gold with a thickness of 20nm / 600nm completes the fabrication of the mercury cadmium telluride detector;

[0050] 7. A 2 μm thick manganese cobalt nickel oxide thin film was deposited on a double-polished sapphire substrate using the sol-gel method;

[0051] 8. A cadmium / gold composite ohmic contact electrode was deposited using dual-ion beam sputtering, with a thickness of 20 nm / 300 nm.

[0052] 9. After photolithography, argon ion etching is used to define the shape of the thermistor. This completes the formation of the manganese cobalt nickel-oxygen thermistor.

[0053] Preparation complete;

[0054] 10. Use epoxy adhesive to bond and press the lower surface of the mercury cadmium telluride detector to the upper surface of the manganese cobalt nickel oxide thermistor, with an adhesive thickness of 1μm;

[0055] 11. Attach the lower surface of the detector module to the cold end of the semiconductor cooler with epoxy adhesive, and then bake it in a 40°C oven for 24 hours.

Claims

1. A vertically integrated, temperature-controlled, cooled mercury cadmium telluride (MdCb) detector assembly, comprising a three-stage semiconductor cooler substrate, a manganese cobalt nickel oxide thermistor (2) above the semiconductor cooler substrate, and a MdCb detector (3) above the manganese cobalt nickel oxide thermistor; wherein the manganese cobalt nickel oxide thermistor structure comprises a sapphire substrate (5), a manganese cobalt nickel oxide thin film (6) on the sapphire substrate, and cadmium / gold composite ohmic contact electrodes (7) on both sides of the upper surface of the manganese cobalt nickel oxide thin film; wherein the MdCb detector structure comprises a sapphire substrate (9), an epoxy resin (10) on the sapphire substrate, and above the epoxy resin, sequentially, an anodic oxide layer (11), a MdCb functional material (12), a sandwich structure of the anodic oxide layer (11), a ZnS antireflection layer (13) above the anodic oxide layer, and indium / gold composite ohmic contact electrodes (14) on both sides of the surface of the MdCb functional material; characterized in that: The detector assembly is vertically integrated by means of epoxy adhesive bonding of a three-stage semiconductor cooler (1), a manganese cobalt nickel oxygen thermistor (2) and a mercury cadmium telluride detector (3). The thermistor is located directly below the mercury cadmium telluride detector, and the sensitive area of ​​the thermistor is completely covered by the mercury cadmium telluride device. The manganese cobalt nickel-oxygen thermistor is in the form of a rectangular coil, and the cadmium / gold composite ohmic contact electrode (7) is located at both ends of the manganese cobalt nickel-oxygen thermistor. The three-stage semiconductor cooler (1) provides a low temperature of -50°C and below, enabling the mercury cadmium telluride detector (3) to operate in a suitable temperature range; the epoxy adhesive bonding the three-stage semiconductor cooler (1) and the manganese cobalt nickel oxide thermistor (2) has a thickness of 1 μm; the epoxy adhesive bonding the manganese cobalt nickel oxide thermistor (2) and the mercury cadmium telluride detector (3) has a thickness of 1 μm.

2. The vertically integrated cooled mercury cadmium telluride detector assembly with precise temperature control according to claim 1, characterized in that: The thickness of the manganese cobalt nickel oxide thermistor film (6) is 2 μm.

3. The vertically integrated cooled mercury cadmium telluride detector assembly with precise temperature control according to claim 1, characterized in that: The functional material (12) of the mercury cadmium telluride detector has a thickness of 10 μm, and there are anodic oxide layers (11) on the upper and lower surfaces. There is a ZnS anti-reflection layer (13) above the anodic oxide layer on the upper surface.

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