HgCdTe molecular beam epitaxy substrate and HgCdTe molecular beam epitaxy device
By setting a silicon carbide coating on the silicon substrate reinforcement surface, the problems of thermal deformation and thermal conduction of silicon substrate are solved, and the structural stability and performance of mercury cadmium telluride molecular beam epitaxy devices are improved.
Patent Information
- Application Number
- CN202423249180.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2034-12-27
AI Technical Summary
In the existing technology, the thermal deformation and thermal conduction problems of silicon substrates during mercury cadmium telluride molecular beam epitaxy have not been effectively solved, affecting the quality of epitaxial layers and device performance.
A silicon carbide coating is deposited on the reinforced surface of the silicon substrate. A dense silicon carbide coating is formed by magnetron sputtering, which achieves high-strength bonding, matches the coefficient of thermal expansion, improves thermal conductivity, and reduces heat radiation loss.
It significantly reduces the deformation of silicon substrates due to temperature changes, lowers the temperature gradient of epitaxial layers, improves epitaxial growth quality and device performance, and enhances mechanical strength and reliability.
Smart Images
Figure CN223899600U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of infrared detectors, and in particular to a mercury cadmium telluride molecular beam epitaxy substrate and a mercury cadmium telluride molecular beam epitaxy device. Background Technology
[0002] Mercury cadmium telluride (MCAD) is an important infrared material widely used in infrared detectors and other fields. Silicon-based MCAD prepared via molecular beam epitaxy (MBE) not only reduces production costs but also improves device integration and reliability. During MBE, the thermal deformation and thermal conductivity of the silicon substrate are key factors affecting the quality of the epitaxial layer and device performance. Traditional silicon substrates are prone to deformation due to high temperatures during MBE, leading to defects in the epitaxial layer and impacting device reliability and stability. Previously, a silicon carbide wafer was laminated onto the back of the silicon substrate to optimize the deformation and thermal conductivity of the silicon substrate.
[0003] A common method to optimize thermal deformation and heat conduction of silicon substrates is to directly laminate a hardened wafer onto the back of the silicon substrate (hardened wafers exhibit less thermal deformation, structural stability, and high strength). However, the bonding strength between the directly laminated hardened wafer and the silicon substrate is relatively low, and its effect on curbing the thermal expansion and deformation of the silicon substrate is not significant. Moreover, this low-strength bonding also affects the heat conduction between the heat radiation source and the silicon substrate, resulting in large temperature differences between various locations on the silicon substrate. This, in turn, degrades the quality of subsequent epitaxial growth. Furthermore, since the substrate needs to be moved and rotated in the equipment, the laminated hardened wafer can lead to substrate structural instability.
[0004] Therefore, how to reduce the thermal deformation of mercury cadmium telluride molecular beam epitaxy substrates while ensuring good substrate thermal conductivity and improving substrate structural stability has become an urgent problem to be solved by those skilled in the art. Utility Model Content
[0005] The purpose of this invention is to provide a mercury cadmium telluride (MDT) molecular beam epitaxial substrate and a MDT molecular beam epitaxial device to solve the problem that existing technologies cannot effectively suppress the thermal deformation of MDT molecular beam epitaxial substrates while also reducing thermal conductivity and affecting structural stability.
[0006] To solve the above-mentioned technical problems, this utility model provides a mercury cadmium telluride molecular beam epitaxy substrate, including a silicon substrate and a silicon carbide coating;
[0007] The silicon substrate includes an epitaxial growth surface and a reinforcing surface; the epitaxial growth surface and the reinforcing surface are a set of opposing surfaces.
[0008] The silicon carbide coating is disposed on the reinforced surface and covers the reinforced surface.
[0009] Optionally, in the mercury cadmium telluride molecular beam epitaxy substrate, the silicon carbide coating is a silicon carbide magnetron sputtering growth layer.
[0010] Optionally, in the said mercury cadmium telluride molecular beam epitaxy substrate, the thickness of the silicon carbide coating ranges from 10 micrometers to 30 micrometers, including endpoint values.
[0011] Optionally, in the said mercury cadmium telluride molecular beam epitaxy substrate, the thickness of the silicon substrate ranges from 599 micrometers to 601 micrometers, including endpoint values.
[0012] Optionally, in the mercury cadmium telluride molecular beam epitaxy substrate, the silicon carbide coating is a heat-treated silicon carbide coating.
[0013] Optionally, in the mercury cadmium telluride molecular beam epitaxy substrate, the silicon carbide coating completely covers the reinforced surface.
[0014] A mercury cadmium telluride (MDT) molecular beam epitaxy device, the MDT molecular beam epitaxy device comprising a mercury cadmium telluride (MDT) molecular beam epitaxy substrate as described in any of the above.
[0015] A component to be plated on a mercury cadmium telluride (MCAD) molecular beam epitaxial substrate, wherein the component to be plated on the MCAD molecular beam epitaxial substrate includes a silicon substrate and a protective capping layer.
[0016] The silicon substrate includes an epitaxial growth surface and a surface to be plated; the epitaxial growth surface and the surface to be plated are a set of opposing surfaces;
[0017] The protective covering layer is disposed on the epitaxial growth surface and completely covers the epitaxial growth surface.
[0018] Optionally, in the part to be plated on the mercury cadmium telluride molecular beam epitaxy substrate, the protective coating layer is a photoresist film layer.
[0019] Optionally, in the workpiece to be plated on the mercury cadmium telluride molecular beam epitaxy substrate, the thickness of the photoresist film layer ranges from 0.5 micrometers to 1.5 micrometers, including endpoint values.
[0020] The mercury cadmium telluride molecular beam epitaxial substrate provided by this utility model includes a silicon substrate and a silicon carbide coating; the silicon substrate includes an epitaxial growth surface and a reinforcement surface; the epitaxial growth surface and the reinforcement surface are a set of opposing surfaces; the silicon carbide coating is disposed on the reinforcement surface and covers the reinforcement surface. This invention achieves a high-strength bond between silicon carbide and the silicon substrate by adding a coating to the silicon substrate surface, thus fabricating silicon carbide on the back side of the silicon substrate (i.e., the reinforced surface). This high-strength bond, combined with the matching thermal expansion coefficients of silicon carbide and the single-crystal silicon wafer, and the significantly higher bending strength of silicon carbide compared to the single-crystal silicon wafer, significantly reduces the deformation of the silicon substrate caused by temperature changes. Furthermore, the thermal conductivity of silicon carbide itself is five times that of the silicon substrate. Combined with the high-strength bond between the silicon carbide coating and the silicon substrate, this significantly reduces the heat loss rate of the heat radiation source, lowers the temperature gradient in the epitaxial layer, and facilitates heat dissipation in subsequent devices. It also greatly reduces the generation of localized high-temperature points during epitaxy, thereby improving the epitaxial growth quality of the mercury cadmium telluride (HCDT) thin film and the performance of the final device. Additionally, the HCDT coating increases the mechanical strength of the silicon substrate, improving the reliability and lifespan of the device. This invention also provides a HCDT molecular beam epitaxy device and a substrate to be coated with HCDT materials, both exhibiting the aforementioned beneficial effects. Attached Figure Description
[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 A schematic diagram of a specific embodiment of the mercury cadmium telluride molecular beam epitaxial substrate provided by this utility model;
[0023] Figure 2 A schematic diagram of a specific embodiment of the mercury cadmium telluride molecular beam epitaxial substrate to be plated according to the present invention;
[0024] Figure 3 A schematic diagram of the magnetron sputtering growth process of a specific embodiment of the mercury cadmium telluride molecular beam epitaxial substrate provided by this utility model.
[0025] Figure 4 This is a schematic diagram of the structure of a mercury cadmium telluride (MCAD) molecular beam epitaxy substrate provided by this utility model after growing a mercury cadmium telluride (MCAD) layer.
[0026] The figure includes 01-silicon substrate, 02-silicon carbide coating, 03-protective capping layer, 04-passivation layer and buffer layer, and 05-mercury cadmium telluride layer. Detailed Implementation
[0027] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0028] The core of this invention is to provide a mercury cadmium telluride molecular beam epitaxy substrate, the structural schematic diagram of one specific embodiment of which is shown below. Figure 1 As shown, this is referred to as Specific Embodiment 1, which includes a silicon substrate 01 and a silicon carbide coating.
[0029] The silicon substrate 01 includes an epitaxial growth surface and a reinforcing surface; the epitaxial growth surface and the reinforcing surface are a set of opposing surfaces;
[0030] The silicon carbide coating is disposed on the reinforced surface and covers the reinforced surface.
[0031] It should be noted that the silicon carbide coating in this invention is not fabricated elsewhere and then transferred to the reinforced surface and connected to it, but is grown directly on the surface of the reinforced surface.
[0032] The silicon carbide coating 02 can be a 3C-silicon carbide coating 02 or other types of silicon carbide coating 02, and this utility model does not limit it.
[0033] Preferably, the silicon carbide coating 02 is a silicon carbide magnetron sputtering grown layer.
[0034] In this preferred embodiment, the silicon carbide coating 02 is further defined as a silicon carbide magnetron sputtering growth layer. The silicon carbide coating 02 obtained by magnetron sputtering deposition is more dense and can significantly improve the uniformity of the silicon carbide coating 02, and has higher production efficiency. Of course, other growth methods of silicon carbide coating 02 can also be used, and this utility model does not limit them here.
[0035] Furthermore, the thickness of the silicon carbide coating 02 ranges from 10 micrometers to 30 micrometers, including endpoints such as 10.0 micrometers, 22.8 micrometers, or 30.0 micrometers; the thickness of the silicon substrate 01 ranges from 599 micrometers to 601 micrometers, including endpoints such as 599.0 micrometers, 600.2 micrometers, or 601.0 micrometers. These ranges represent the optimal ranges after extensive theoretical calculations and practical testing. Within these ranges, the low cost of the silicon carbide coating 02 can be maintained, while also ensuring that the silicon carbide coating 02 enhances the thermal deformation resistance and thermal conductivity of the silicon substrate 01. Of course, the above parameters can be adjusted according to actual conditions, and this invention does not limit this adjustment.
[0036] Furthermore, the silicon carbide coating 02 is a heat-treated silicon carbide coating 02. The heat-treated silicon carbide coating 02, while completing crystallization, also releases residual stress, further enhancing the silicon carbide coating 02's resistance to thermal deformation of the silicon substrate 01, and also improving the device's operational stability.
[0037] In addition, the silicon carbide coating 02 completely covers the reinforced surface.
[0038] Completely covering the reinforced surface of the silicon substrate 01 with the silicon carbide coating 02 can maximize the thermal stress resistance of the silicon substrate 01, and reduce the likelihood of stress concentration and localized high-temperature points during epitaxial growth, thereby improving the operational stability of the device. Of course, the silicon carbide coating 02 may also partially cover the reinforced surface; this invention is not limited thereto.
[0039] The mercury cadmium telluride molecular beam epitaxial substrate provided by this utility model includes a silicon substrate 01 and a silicon carbide coating; the silicon substrate 01 includes an epitaxial growth surface and a reinforcement surface; the epitaxial growth surface and the reinforcement surface are a set of opposing surfaces; the silicon carbide coating is disposed on the reinforcement surface and covers the reinforcement surface. This invention achieves a high-strength bond between silicon carbide and the silicon substrate 01 by adding a coating to the surface of the silicon substrate 01, thus fabricating silicon carbide on the back side of the silicon substrate 01 (i.e., the reinforced surface). This high-strength bond, combined with the matching thermal expansion coefficients between silicon carbide and the single-crystal silicon wafer and the bending strength of silicon carbide far exceeding that of the single-crystal silicon wafer, can significantly reduce the deformation of the silicon substrate caused by temperature changes. In addition, the thermal conductivity of silicon carbide itself is five times that of the silicon substrate 01. Furthermore, the high-strength bond between the silicon carbide coating and the silicon substrate 01 significantly reduces the loss rate of the heat radiation source, reduces the temperature gradient in the epitaxial layer, and facilitates heat dissipation of subsequent devices. This greatly reduces the generation of local high-temperature points during epitaxy, thereby improving the epitaxial growth quality of the mercury cadmium telluride thin film and the performance of the final device. Moreover, the silicon carbide coating can increase the mechanical strength of the silicon substrate, improving the reliability and lifespan of the device.
[0040] This invention also provides a mercury cadmium telluride (MDT) molecular beam epitaxy device, which includes a MDT molecular beam epitaxy substrate as described in any of the above descriptions.
[0041] The technical features of the mercury cadmium telluride (MDT) molecular beam epitaxial device in this specific embodiment can be referred to the mercury cadmium telluride (MDT) molecular beam epitaxial substrate mentioned above, and will not be repeated here. The mercury cadmium telluride (MDT) molecular beam epitaxial substrate provided by this utility model includes a silicon substrate 01 and a silicon carbide coating; the silicon substrate 01 includes an epitaxial growth surface and a reinforcement surface; the epitaxial growth surface and the reinforcement surface are a set of opposing surfaces; the silicon carbide coating is disposed on the reinforcement surface, and the silicon carbide coating covers the reinforcement surface. This invention achieves a high-strength bond between silicon carbide and the silicon substrate 01 by adding a coating to the surface of the silicon substrate 01, thus fabricating silicon carbide on the back side of the silicon substrate 01 (i.e., the reinforced surface). This high-strength bond, combined with the matching thermal expansion coefficients between silicon carbide and the single-crystal silicon wafer and the bending strength of silicon carbide far exceeding that of the single-crystal silicon wafer, can significantly reduce the deformation of the silicon substrate caused by temperature changes. In addition, the thermal conductivity of silicon carbide itself is five times that of the silicon substrate 01. Furthermore, the high-strength bond between the silicon carbide coating and the silicon substrate 01 significantly reduces the loss rate of the heat radiation source, reduces the temperature gradient in the epitaxial layer, and facilitates heat dissipation of subsequent devices. This greatly reduces the generation of local high-temperature points during epitaxy, thereby improving the epitaxial growth quality of the mercury cadmium telluride thin film and the performance of the final device. Moreover, the silicon carbide coating can increase the mechanical strength of the silicon substrate, improving the reliability and lifespan of the device.
[0042] This utility model also provides a substrate to be plated for mercury cadmium telluride molecular beam epitaxy, and a schematic diagram of one specific embodiment is shown below. Figure 2 As shown, referred to as Specific Embodiment Two, the substrate to be plated in the mercury cadmium telluride molecular beam epitaxial substrate includes a silicon substrate 01 and a protective capping layer 03.
[0043] The silicon substrate 01 includes an epitaxial growth surface and a surface to be plated; the epitaxial growth surface and the surface to be plated are a set of opposing surfaces;
[0044] The protective covering layer 03 is disposed on the epitaxial growth surface and completely covers the epitaxial growth surface.
[0045] It should be noted that, in the present invention, the mercury cadmium telluride (MDT) molecular beam epitaxial substrate is obtained after the silicon carbide coating 02 mentioned above is applied to the surface to be coated. Of course, the protective capping layer 03 is used to protect the epitaxial growth surface of the silicon substrate 01 during the application of the silicon carbide coating 02, and to prevent the epitaxial growth surface from being contaminated by silicon carbide. After the silicon carbide coating 02 is applied to the surface to be coated, the protective capping layer 03 needs to be removed before mercury cadmium telluride (MDT) molecular beam epitaxial growth is performed on the epitaxial growth surface.
[0046] Preferably, the protective cover layer 03 is a photoresist film layer. The photoresist film layer is dense and can play a good protective role for the epitaxial growth surface. At the same time, the photoresist film is easy to remove and has low residue, so it will not affect the subsequent mercury cadmium telluride molecular beam epitaxial growth.
[0047] Furthermore, the thickness of the photoresist film layer ranges from 0.5 micrometers to 1.5 micrometers, including endpoint values such as any one of 0.50 micrometers, 1.02 micrometers, or 1.50 micrometers. Within the above range, the photoresist film can provide good protection during the silicon carbide setup process (such as magnetron sputtering) and also achieve low residue of the photoresist film in subsequent processes.
[0048] The following provides a complete fabrication process for mercury cadmium telluride molecular beam epitaxy substrates, including:
[0049] Step 1: Select a high-quality silicon substrate 01 as the silicon substrate, and perform rigorous cleaning and pretreatment using a substrate cleaner to obtain a clean silicon substrate surface. To prevent the front side of the silicon substrate from being contaminated by the magnetron sputtering process, a protective layer 03 is applied to the front side of the silicon substrate by spin-coating a protective layer.
[0050] Step 2: Perform magnetron sputtering on the silicon substrate obtained in Step 1. After fabricating a silicon carbide film of suitable thickness on the back side of the silicon substrate using magnetron sputtering, remove the mask on the front side of the silicon substrate. Finally, anneal the substrate at 600 °C to convert the silicon carbide film into a crystalline state while releasing residual stress. (See reference...) Figure 3 , Figure 3 This is a schematic diagram of the process of silicon substrate in magnetron sputtering.
[0051] Step 3: Remove the silicon substrate with silicon carbide on the back side obtained in Step 2, and place it into the molecular beam epitaxy equipment with the front side facing the furnace nozzle. Perform epitaxial growth of the passivation layer and buffer layer 04, and the mercury cadmium telluride layer 05. (Refer to...) Figure 4 , Figure 4 This is a schematic diagram of the structure after the growth of the mercury cadmium telluride layer.
[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.
[0053] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0054] The foregoing has provided a detailed description of the mercury cadmium telluride (MCAD) molecular beam epitaxy substrate and the MCAD molecular beam epitaxy device provided by this utility model. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this utility model.
Claims
1. A mercury cadmium telluride molecular beam epitaxy substrate, characterized in that, Including the silicon substrate and the silicon carbide coating; The silicon substrate includes an epitaxial growth surface and a reinforcing surface; the epitaxial growth surface and the reinforcing surface are a set of opposing surfaces. The silicon carbide coating is disposed on the reinforced surface and covers the reinforced surface.
2. The mercury cadmium telluride molecular beam epitaxy substrate as described in claim 1, characterized in that, The silicon carbide coating is a silicon carbide magnetron sputtering grown layer.
3. The mercury cadmium telluride molecular beam epitaxy substrate as described in claim 1, characterized in that, The thickness of the silicon carbide coating ranges from 10 micrometers to 30 micrometers, including the endpoint values.
4. The mercury cadmium telluride molecular beam epitaxy substrate as described in claim 1, characterized in that, The thickness of the silicon substrate ranges from 599 micrometers to 601 micrometers, including endpoints.
5. The mercury cadmium telluride molecular beam epitaxy substrate as described in claim 1, characterized in that, The silicon carbide coating is a heat-treated silicon carbide coating.
6. The mercury cadmium telluride molecular beam epitaxy substrate as described in claim 1, characterized in that, The silicon carbide coating completely covers the reinforced surface.
7. A mercury cadmium telluride molecular beam epitaxy device, characterized in that, The mercury cadmium telluride molecular beam epitaxy device includes the mercury cadmium telluride molecular beam epitaxy substrate as described in any one of claims 1 to 6.
8. A substrate to be plated using mercury cadmium telluride molecular beam epitaxy, characterized in that, The substrate to be plated in the mercury cadmium telluride molecular beam epitaxy substrate includes a silicon substrate and a protective capping layer; The silicon substrate includes an epitaxial growth surface and a surface to be plated; the epitaxial growth surface and the surface to be plated are a set of opposing surfaces; The protective covering layer is disposed on the epitaxial growth surface and completely covers the epitaxial growth surface.
9. The part to be plated on the mercury cadmium telluride molecular beam epitaxy substrate as described in claim 8, characterized in that, The protective coating layer is a photoresist film layer.
10. The workpiece to be plated on the mercury cadmium telluride molecular beam epitaxy substrate as described in claim 9, characterized in that, The thickness of the photoresist film layer ranges from 0.5 micrometers to 1.5 micrometers, including the endpoint values.