Chip-level nuclear battery based on radiation volt effect and thermoelectric conversion effect and application thereof

Abstract

The application relates to a chip-level nuclear battery based on a radiation volt effect and a thermoelectric conversion effect and application thereof, which is composed of a radioactive isotope layer, a PIN junction transducer device, a thermoelectric transducer device and an isolation protection layer, and the utilization rate of beta ray energy is improved. The high integration and miniaturization preparation of the PIN junction transducer device and the thermoelectric transducer device are realized by using a MEMS processing technology, and the interface failure problem in the traditional process is solved. In addition, the nuclear battery has the characteristics of modularity, and a power supply group can be formed by series connection to supply power for an integrated circuit.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor devices, and relates to a chip-level nuclear battery based on radiation volt effect and thermoelectric conversion effect. BACKGROUND

[0002] Miniaturization, microfabrication and integration of electronic products are the general trend of the world technology development, and microelectromechanical system (MEMS) is one of the most important technical innovations in recent years. The progress of sensor technology, microelectromechanical system, modern network and wireless communication technology promotes the generation and development of wireless sensor network with modern significance, which gradually shows important application value in the fields of national defense, industry, construction, biomedicine, etc. The traditional power supply mode using storage battery cannot meet or adapt to specific working environment and requirements, and microelectromechanical system also loses the space for further development without corresponding micro power supply.

[0003] Common micro batteries include micro fuel cells, micro chemical batteries, micro solar cells and micro internal combustion engines. Micro fuel cells, micro chemical batteries and micro internal combustion engines need to continuously supplement fuel or intermittent charging from the outside, and the supplementing fuel or charging process has high requirements on the preparation process of the battery, which increases the equipment cost. In addition, their energy conversion efficiency is low, and it is also difficult to miniaturize and integrate to the micron level.

[0004] Micro solar cells have the characteristics of cleanliness, safety, mature technology, etc. They can also be miniaturized and integrated to the micro-nano level by using micro-nano processing technology. Therefore, micro solar cells are a suitable choice for microelectromechanical system power supply. However, since micro solar cells rely on sunlight to work, this type of battery cannot work normally in an unstable sunlight environment. Nuclear batteries have the advantages of light weight, small size, long service life, high energy density, stable output performance, low maintenance service frequency, and do not need external sunlight, etc. Therefore, micro nuclear batteries are an ideal power supply for integrated circuit systems. SUMMARY

[0005] The purpose of the present application is to provide a chip-level nuclear battery based on radiation volt effect and thermoelectric conversion effect and its application.

[0006] The purpose of the present application can be achieved by the following technical solutions:

[0007] One of the technical solutions of the present application provides a chip-level nuclear battery based on radiation volt effect and thermoelectric conversion effect, comprising a PIN junction transducer device, a thermoelectric transducer device arranged in sequence from top to bottom, and an isolation shield covering the PIN junction transducer device and the thermoelectric transducer device, wherein the PIN junction transducer device comprises a high-resistance substrate, a lower electrode, a PIN junction transducer unit and an upper electrode which are sequentially compounded on the high-resistance substrate, and the thermoelectric transducer device comprises a second substrate, a bottom electrode on the substrate, a top electrode above the bottom electrode, and a series-connection structure thermoelectric column between the bottom electrode and the top electrode, and the upper surface of the upper electrode is further provided with a radioactive isotope layer, and the bottom electrode is further connected with the upper electrode through an internal circuit.

[0008] Further, the series-connection structure thermoelectric column comprises P-type thermoelectric columns and N-type thermoelectric columns, the bottom electrode and the top electrode are arranged in sections, adjacent P-type thermoelectric columns and N-type thermoelectric columns are connected through the sectional top electrode or bottom electrode, and all the P-type thermoelectric columns and N-type thermoelectric columns form a series-connection structure.

[0009] Further, the series-connection structure thermoelectric column comprises P-type thermoelectric columns and N-type thermoelectric columns, the bottom electrode and the top electrode are arranged in sections, adjacent P-type thermoelectric columns and N-type thermoelectric columns are connected through the sectional top electrode or bottom electrode, and all the P-type thermoelectric columns and N-type thermoelectric columns form a series-connection structure.

[0010] Further, the PIN junction transducer unit forms ohmic contact with the upper electrode and the lower electrode.

[0011] Further, the PIN junction in the PIN junction transducer unit is a silicon carbide PIN junction or a gallium nitride PIN junction, and the number of PIN junctions is n, n≥1.

[0012] Further, the PIN junction transducer unit is prepared by epitaxial growth technology or magnetron sputtering technology.

[0013] Further, the upper electrode and the lower electrode are independently gold, silver, platinum or copper.

[0014] Further, the top electrode and the bottom electrode are independently gold, silver, platinum or copper.

[0015] Further, the PIN junction transducer device and the thermoelectric transducer device are assembled together by adsorption, bonding or bonding.

[0016] Further, the second substrate is a semiconductor thin film, an oxide thin film or an organic thin film.

[0017] In the present application, the utilization rate of beta ray energy by the PIN junction transducer device is limited, and most of the beta ray energy is released in the form of heat energy. The thermoelectric transducer device can convert the heat energy generated by the semiconductor PIN junction device into electrical energy, thereby improving the utilization rate of beta ray energy by the nuclear battery.

[0018] The second technical solution of the present application provides an application of a chip-level nuclear battery based on the radiation volt effect and the thermoelectric conversion effect, which is used in an integrated circuit and provides power for the integrated circuit device.

[0019] Further, the integrated circuit device is arranged on the second substrate and is connected to the lower electrode and the bottom electrode of the chip-level nuclear battery through internal circuits respectively.

[0020] Further, the chip-level nuclear battery is provided with one or more, and when the chip-level nuclear battery is provided with multiple, all the chip-level nuclear batteries are connected in series to form a power supply group and provide power for the integrated circuit device.

[0021] Further, the integrated circuit device is composed of transistors, resistors, capacitors, inductors and the like.

[0022] The conventional nuclear battery can only utilize part of the beta ray energy and convert it into electric energy, and most of the beta ray energy is dissipated in the form of heat energy and cannot be utilized. The present application introduces a thermoelectric conversion device into the nuclear battery, realizes the reuse of low-quality waste heat in the nuclear battery, improves the utilization efficiency of the beta ray energy of the nuclear battery as a whole, and thus can provide long-term stable energy supply for the integrated circuit. The particle bombarding the PIN junction conversion unit during the decay of the radioactive isotope releases a large number of electron-hole pairs in the material, which move directionally under the action of the built-in electric field to form an electric current. A large amount of heat is released during the decay of the radioactive isotope and the process of the particle bombarding the nuclear conversion material, which can drive the directional movement of the electron-hole pairs in the N-type thermoelectric column and the P-type thermoelectric column, thereby generating an electric current. The comprehensive utilization of these two ways of generating an electric current can improve the overall output performance of the device. In the present application, the radioactive isotope layer, the PIN junction conversion device and the thermoelectric conversion device are arranged in a "sandwich" structure, which can increase the contact area and improve the utilization rate of the isotope decay energy. The high-resistance substrate is used to isolate the PIN junction conversion device and the top electrode to prevent the electrons in the top electrode material from neutralizing the holes in the PIN junction conversion unit. In addition, the high-resistance substrate can also make the heat generated by the nuclear conversion device more uniformly introduced into the thermoelectric conversion device, thereby improving the utilization rate of the heat energy.

[0023] The conventional welding technology needs to use various adhesives to connect the components, which increases the interfacial thermal resistance, reduces the interfacial stability, and has an adverse effect on the output performance, reliability and service life of the device as a whole. At the same time, this method is difficult to use in the processing of micro devices. The present application uses MEMS processing technology to realize the high-integration and miniaturization of the thermoelectric conversion device and the PIN junction conversion device, solves the interfacial failure problem in the conventional process, and is conducive to improving the stability of the nuclear battery and prolonging the service life of the nuclear battery. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A schematic diagram of forming a top-down structure for the chip-level nuclear battery and the integrated circuit device;

[0025] Figure 2 A schematic diagram of forming a left-right structure for the chip-level nuclear battery and the integrated circuit device;

[0026] Figure 3 A schematic diagram of forming a power supply group by series connection of two chip-level nuclear batteries;

[0027] Figure 4 An energy conversion diagram of the chip-level nuclear battery;

[0028] Marked description in the figure:

[0029] 1, isolation protection layer; 2, radioisotope layer; 3, upper electrode; 4, PIN junction transducer unit; 5, lower electrode; 6, high resistance substrate; 7, internal circuit; 8, bottom electrode; 9, P-type thermoelectric column; 10, N-type thermoelectric column; 11, top electrode; 12, second substrate; 13, integrated circuit device. DETAILED DESCRIPTION

[0030] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments are implemented on the basis of the technical solutions of the present application, and detailed implementation methods and specific operation processes are given, but the protection scope of the present application is not limited to the following embodiments.

[0031] In the following embodiments, HJ3527 type photoresist, LOL2000 type photoresist and HJ238 type developing solution are purchased from Huaji Semiconductor (Shanghai) Co., Ltd., and the target material is purchased from Zhongnuo New Material (Beijing) Technology Co., Ltd.

[0032] The remaining raw materials or processing techniques, unless otherwise specified, are all conventional commercially available raw materials or conventional processing techniques in the art.

[0033] Example 1:

[0034] The embodiments of the present application are based on standard MEMS processing technology, and utilize exposure, development, thin film deposition and stripping process to provide a technical solution and preparation method for processing chip-level nuclear battery on a substrate:

[0035] Step 1: spin-coat LOL2000 type photoresist on a silicon oxide substrate (i.e. second substrate 12), and perform ultraviolet exposure patterning with a mask.

[0036] Step 2: wash away the photoresist of the exposed part in HJ238 type developing solution.

[0037] Step 3: deposit 20nm chromium and 200nm gold by magnetron sputtering.

[0038] Step 4: Put into acetone for soaking and peeling, leaving the bottom electrode 8.

[0039] Step 5: Use magnetron sputtering to deposit Bi2Te3 as N-type thermoelectric column 10 and Sb2Te3 as P-type thermoelectric column 9 on the bottom electrode 8, with a height of 2 μm and 4 pairs of thermoelectric columns.

[0040] Step 6: Spin-coat HJ3527 type photoresist as a support structure and perform ultraviolet exposure patterning, with the same height as the thermoelectric column.

[0041] Step 7: Deposit gold as the top electrode 11 above the support structure, with a thickness of 200 nm.

[0042] Step 8: Use oxygen plasma treatment to remove the support structure, forming a thermoelectric transducer device, and at this time, the N-type thermoelectric column 10 and the P-type thermoelectric column 9 are connected through the top electrode 11 and the bottom electrode 8 to form a series structure.

[0043] Step 9: Absorb a 200 μm single crystal silicon carbide substrate, i.e. high resistance substrate 6, of the same size as the top electrode 11 of the thermoelectric transducer device.

[0044] Step 10: Epitaxially grow a 100 nm gold layer as the lower electrode 5 on the single crystal silicon carbide substrate.

[0045] Step 11: Use microwave plasma chemical vapor deposition technology and ion implantation technology to epitaxially grow a P-type high-doped silicon carbide layer (doping atom concentration of about 5×10 17 / cm 3 ), an intrinsic silicon carbide layer and an N-type high-doped silicon carbide layer (doping atom concentration of about 5×10 17 / cm 3 ) on the gold layer of the single crystal silicon carbide substrate in sequence, forming a PIN junction transducer unit 4 with a silicon carbide PIN junction number of 1 and a thickness of 10 μm.

[0046] Step 12: Epitaxially grow a 100 nm gold layer as the upper electrode 3 on the silicon carbide PIN junction.

[0047] Step 13: Absorb a nickel-63 with a thickness of 2 μm as the radioisotope layer 2 above the upper electrode 3.

[0048] Step 14: Use the internal circuit 7 to connect the top electrode 11 and the bottom electrode 8 of the thermoelectric transducer device, and the upper electrode 3 and the lower electrode 5 of the PIN junction transducer device in series, and connect them into the integrated circuit device 13 below. Figure 1

[0049] ​Step 15: Set up a isolation shield 1 outside the nuclear battery.

[0050] Example 2:

[0051] Most of them are the same as example 1, except that the number of thermoelectric pillars is 512 in this example.

[0052] Example 3:

[0053] Most of them are the same as example 1, except that the number of silicon carbide PIN junctions is 5 in this example.

[0054] Example 4:

[0055] Most of them are the same as example 1, except that the nuclear battery is located on the side of the integrated circuit device 13 (as shown in Figure 2 ).

[0056] Example 5:

[0057] Most of them are the same as example 4, except that the power supply group is composed of two nuclear batteries connected in series (as shown in Figure 3 ). At this time, the bottom electrode 8 of the two nuclear batteries is connected, and the lower electrode 5 of the previous nuclear battery is also connected to the upper electrode 3 of the next nuclear battery through the internal circuit 7 in the direction towards the integrated circuit device 13.

[0058] In general, traditional nuclear batteries can only utilize part of the beta ray energy and convert it into electrical energy, while most of the beta ray energy is dissipated in the form of heat energy and cannot be utilized. The present application introduces a thermoelectric transducer into the nuclear battery, which realizes the reuse of low-quality waste heat in the nuclear battery and improves the utilization efficiency of the beta ray energy of the nuclear battery as a whole Figure 4 ), so as to provide long-term stable energy supply for the integrated circuit. In addition, the present application realizes the high integration and miniaturization of the thermoelectric transducer and the PIN junction transducer by using MEMS processing technology, solves the interface failure problem in traditional process, and is conducive to improving the stability of the nuclear battery and prolonging the service life of the nuclear battery.

[0059] The above description of the embodiments is for the convenience of those skilled in the art to understand and use the invention. Those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described herein to other embodiments without having to go through creative labor. Therefore, the present application is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present application should be within the scope of protection of the present application.

Claims

1. A chip-scale nuclear battery based on the radiation voltaic effect and the thermoelectric conversion effect, characterized in that, The chip-level nuclear battery comprises, from top to bottom, a PIN junction transducer, a thermoelectric transducer, and a protective shield covering the PIN junction transducer and the thermoelectric transducer, wherein the PIN junction transducer comprises a high-resistance substrate, a lower electrode, a PIN junction transducing unit and an upper electrode which are sequentially compounded on the high-resistance substrate, and the thermoelectric transducer comprises a second substrate, a bottom electrode on the substrate, a top electrode above the bottom electrode, and a series-connection structure thermoelectric column between the bottom electrode and the top electrode; the upper surface of the upper electrode is further provided with a radioactive isotope layer, and the bottom electrode is further connected with the upper electrode through an internal circuit. The series-connection structure thermoelectric column comprises P-type thermoelectric columns and N-type thermoelectric columns, and the bottom electrode and the top electrode are arranged in segments, the adjacent P-type thermoelectric columns and N-type thermoelectric columns are connected through the segmented top electrode or bottom electrode, and all the P-type thermoelectric columns and N-type thermoelectric columns form a series-connection structure. The series-connection structure of the series-connection structure thermoelectric column has m periods, and m is greater than or equal to 1. The PIN junction transducing unit forms ohmic contact with the upper electrode and the lower electrode.

2. The chip-scale nuclear battery based on the radiation voltaic effect and the thermoelectric conversion effect according to claim 1, characterized in that, The PIN junction in the PIN junction transducing unit is a silicon carbide PIN junction or a gallium nitride PIN junction, and the number of PIN junctions is n, and n is greater than or equal to 1.

3. A chip-scale nuclear battery based on the radiovoltaic effect and the thermoelectric conversion effect according to claim 2, characterized in that, The PIN junction transducing unit is prepared by epitaxial growth technology or magnetron sputtering technology.

4. The chip-scale nuclear battery based on the radiation voltaic effect and the thermoelectric conversion effect according to claim 1, characterized in that, The upper electrode and the lower electrode are independently gold, silver, platinum or copper. The top electrode and the bottom electrode are independently gold, silver, platinum or copper.

5. The chip-scale nuclear battery based on the radiation voltaic effect and the thermoelectric conversion effect according to claim 1, characterized in that, The PIN junction transducer and the thermoelectric transducer are assembled together by adsorption, bonding or bonding.

6. Use of a chip-scale nuclear battery based on the radiovoltaic effect and the thermoelectric conversion effect according to any one of claims 1 to 5, characterized in that, The chip-level nuclear battery is used in an integrated circuit and supplies power to the integrated circuit device.

7. Use of a chip-scale nuclear battery based on the radiovoltaic effect and the thermoelectric conversion effect according to claim 6, characterized in that, The integrated circuit device is arranged on the second substrate and connected with the lower electrode and the bottom electrode of the chip-level nuclear battery through an internal circuit. The chip-level nuclear battery is provided with one or more, and when the chip-level nuclear battery is provided with multiple, all the chip-level nuclear batteries are connected in series to form a power supply group and supply power to the integrated circuit device.

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