CN113990550B - Planar Pin type beta irradiation battery with passivation layer surface field and preparation method - Google Patents
Planar Pin type beta irradiation battery with passivation layer surface field and preparation method Download PDFInfo
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Abstract
The invention relates to a planar PiN type beta irradiation battery with a passivation layer surface field and a preparation method thereof, wherein the irradiation battery comprises a PiN unit and a radioisotope unit positioned on the PiN unit, the PiN unit comprises an N type doped 4H-SiC substrate, an N type doped 4H-SiC epitaxial layer, a P type ion implantation region, an N type ohmic contact electrode, a first passivation layer, a second passivation layer and a P type ohmic contact electrode, and the P type ion implantation region is positioned in the surface layer of the N type doped 4H-SiC epitaxial layer to form a distributed P type region; the first passivation layer is positioned on the N-type doped 4H-SiC epitaxial layer and covers the surface of the isolation mesa; the second passivation layer is positioned on the first passivation layer at the isolation mesa; the P-type ohmic contact electrode is positioned on the P-type ion implantation region and is arranged alternately with the first passivation layer. The irradiation battery reduces the energy deposition of beta rays in a P-type region, improves the short-circuit current Isc, the open-circuit voltage Voc and the filling factor FF, and achieves the purpose of improving the energy conversion efficiency of the beta irradiation battery.
Description
Technical Field
The invention belongs to the technical field of microelectronics, and particularly relates to a planar Pin type beta irradiation battery with a passivation layer surface field and a preparation method thereof.
Background
The Micro nuclear battery or radioisotope battery has the advantages of small volume, light weight, long service life, easy integration, no influence of external environment on work and the like, can be used for solving the long-term power supply problems of aerospace deep space exploration, artificial cardiac pacemakers, portable mobile electronic products, implanted microsystems and the like, and is considered as one of ideal long-term energy sources for Micro-electric-Mechanical System (MEMS for short), sensors and the like.
Beta irradiation cell is a type of use 3 H、 63 Ni and 147 shellfish emitted by Pm and other radioactive isotopesA semiconductor isotope battery for outputting electric energy by the radiation volt effect of the tower (beta-Particle) rays. In 1953, the rapport study shows that the beta rays generated by isotope decay can generate electron-hole pairs in a silicon PN junction, and a carrier collection process similar to a photovoltaic Effect occurs, and finally, the beta rays are converted into electric energy to be output, and the phenomenon is called radiation Ford Effect (beta-Voltaic Effect). In 1957, elgin-Kidde first used β -Voltaic Effect on power supply, successfully manufactured the first isotope microbattery (β -Voltaic Battery).
Since 2006, with advances in preparation and process technology of wide bandgap semiconductor materials SiC, relevant reports of SiC-based isotope microbatteries have emerged. Silicon carbide has the characteristics of large forbidden bandwidth, strong thermal stability, high thermal conductivity, large carrier saturation rate, excellent anti-irradiation performance and the like, and the characteristics are beneficial to improving the energy conversion efficiency and the stability of the output performance of the beta-irradiation battery. In recent decades, the total conversion efficiency of beta irradiation cells has been improved from 0.2% to nearly 4% thanks to the use of wide bandgap semiconductor materials, with an energy conversion efficiency of 18.6% for silicon carbide PiN devices.
However, in the prior report, the energy conversion efficiency of the silicon carbide diode device under ideal conditions can reach 23.5%, which is far higher than the experimental result, and the reason is mainly that the energy deposition of beta rays in the silicon carbide material decays exponentially with the incidence depth, and a large number of electron-hole pairs generated by irradiation are positioned in the range of 1 mu m of the surface of the device, so that the surface recombination and the dead layer thickness of the P-type region of the silicon carbide PiN device have a significant influence on the energy conversion efficiency.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a conventional silicon carbide PiN type β irradiation cell provided in the prior art, and the PiN nuclear cell includes, from top to bottom, a radioactive source 60, a P-type ohmic contact electrode 50, a P-type highly doped SiC layer 30, an intrinsic i layer 20, an N-type highly doped SiC substrate 10 and an N-type ohmic contact electrode 40; the surface recombination of the P-type highly doped SiC layer 30 reduces the collection efficiency of electron-hole pairs generated by beta rays in a semiconductor on one hand, so that short-circuit current Isc is reduced, and the saturation current of a PiN device is increased on the other hand, so that open-circuit voltage Voc and fill factor FF are reduced; the relatively thick P-type highly doped SiC layer 30 will further enhance the negative effects of surface recombination while increasing dead layer losses. And the maximum output power pout=ff·isc·voc of the beta-irradiation cell, so the surface recombination and the P-type region dead layer thickness will limit the energy conversion efficiency of the silicon carbide PiN-type beta-irradiation cell. In addition, in order to avoid the ohmic contact electrode from blocking incident ions, the structure simply makes the P-type ohmic electrode at one corner of the device, so that radiation generated carriers far away from the P-type ohmic electrode are compounded in the transportation process, and the energy conversion rate is reduced.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a planar Pin type beta irradiation battery with a passivation layer surface field and a preparation method thereof. The technical problems to be solved by the invention are realized by the following technical scheme:
the embodiment of the invention provides a planar PiN type beta irradiation battery with a passivation layer surface field, which comprises a PiN unit and a radioisotope unit positioned on the PiN unit, wherein the PiN unit comprises an N type doped 4H-SiC substrate, an N type doped 4H-SiC epitaxial layer, a P type ion implantation region, an N type ohmic contact electrode, a first passivation layer, a second passivation layer and a P type ohmic contact electrode,
the N-type ohmic contact electrode, the N-type doped 4H-SiC substrate and the N-type doped 4H-SiC epitaxial layer are sequentially laminated, and an isolation table top is arranged on the periphery side of the N-type doped 4H-SiC epitaxial layer;
the P-type ion implantation region is positioned in the surface layer of the N-type doped 4H-SiC epitaxial layer to form a distributed P-type region;
the first passivation layer is positioned on the N-type doped 4H-SiC epitaxial layer and covers the surface of the isolation mesa;
the second passivation layer is positioned on the first passivation layer at the isolation mesa;
the P-type ohmic contact electrode is positioned on the P-type ion implantation region and is arranged alternately with the first passivation layer;
the radioisotope unit is positioned above the first passivation layer and the P-type ohmic contact electrode.
In one embodiment of the present invention, the doping concentration of the P-type ion implantation region is 1×10 19 ～5×10 19 cm -3 The implantation depth is 0.2-0.5 mu m, the width is 10-20 mu m, and the interval between adjacent implantation regions in the P-type ion implantation region is 100-1000 mu m.
In one embodiment of the invention, the P-type ohmic contact electrode comprises a plurality of longitudinal rectangular strips and a plurality of transverse rectangular strips, wherein the longitudinal rectangular strips are distributed in parallel, the transverse rectangular strips are distributed in parallel, and each transverse rectangular strip is connected with the longitudinal rectangular strips.
In one embodiment of the invention, a plurality of the longitudinal rectangular bars are equally spaced apart, a plurality of the transverse rectangular bars are equally spaced apart and vertically bisect the longitudinal rectangular bars.
In one embodiment of the invention, the number of longitudinal rectangular bars is greater than or equal to 5 and the number of transverse rectangular bars is greater than or equal to 1; the width of the longitudinal rectangular strips and the width of the transverse rectangular strips are 10-20 mu m, and the interval between the longitudinal rectangular strips is 100-1000 mu m.
In one embodiment of the invention, the P-type ohmic contact electrode comprises a plurality of circular rings and a plurality of rectangular strips, wherein the circular rings are sequentially nested in the order from small to large in radius, and each rectangular strip is connected with the circular rings.
In one embodiment of the invention, the rings are concentric circles distributed at equal intervals, the ring spacing is equal to the inner diameter of the central ring, and the rectangular bars are distributed at equal angles.
In one embodiment of the invention, the number of the circular rings is greater than or equal to 5, and the number of the rectangular strips is greater than or equal to 4; the width of the circular ring and the width of the rectangular strip are 10-20 mu m, and the ring spacing and the inner diameter of the central circular ring of the circular ring are 100-1000 mu m.
In one embodiment of the invention, the radioisotope unit includes a radioisotope source layer over the plurality of first passivation layers and the P-type ohmic contact electrode.
Another embodiment of the present invention provides a method for preparing a planar PiN type β -irradiation battery having a passivation layer surface field, comprising the steps of:
s1, epitaxially growing an N-type doped 4H-SiC epitaxial layer on an N-type doped 4H-SiC substrate;
s2, carrying out mesa etching on the N-doped 4H-SiC epitaxial layer to form an isolation mesa;
s3, performing ion implantation in the surface layer of the N-type doped 4H-SiC epitaxial layer to form a distributed P-type ion implantation region;
s4, preparing a first passivation layer on the surface of the N-type doped 4H-SiC epitaxial layer and the surface of the isolation mesa;
s5, preparing a second passivation layer on the first passivation layer at the isolation mesa;
s6, preparing a P-type ohmic contact electrode on the P-type ion implantation region, so that the P-type ohmic contact electrode and the first passivation layer are arranged alternately;
s7, epitaxially growing an N-type ohmic contact electrode on the back surface of the N-type doped 4H-SiC substrate;
s8, preparing a radioisotope unit above the first passivation layer and the P-type ohmic contact electrode.
Compared with the prior art, the invention has the beneficial effects that:
according to the irradiation battery disclosed by the invention, the distributed P-type ion implantation region is formed in the surface layer of the N-type doped 4H-SiC epitaxial layer, the P-type ohmic contact electrode is prepared on the distributed P-type region, and the surface outside the P-type region is subjected to passivation layer treatment, so that the surface of the N-type epitaxial layer is covered with the first passivation layer, the energy deposition of beta rays in the P-type region is reduced, the surface recombination effect of a device is weakened, the collection efficiency of ohmic contact electrodes on carriers generated by irradiation is improved, the recombination of the carriers generated by irradiation in the transportation process is reduced, the saturation current of the device is reduced, and the short-circuit current Isc, the open-circuit voltage Voc and the filling factor FF are further improved, so that the energy conversion efficiency of the beta irradiation battery is improved.
Drawings
Fig. 1 is a schematic structural diagram of a conventional silicon carbide PiN type β irradiation cell provided in the prior art;
fig. 2 is a schematic structural diagram of a planar PiN-type β -cell with a passivation layer surface field according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a gate P-type ohmic contact electrode according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of an annular P-type ohmic contact electrode according to an embodiment of the present invention;
fig. 5 a-5 j are schematic process diagrams of a method for preparing a planar PiN-type β -cell with a passivation layer surface field according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to specific examples, but embodiments of the present invention are not limited thereto.
Example 1
Referring to fig. 2, fig. 2 is a schematic structural diagram of a planar PiN-type β -cell with passivation layer surface field according to an embodiment of the present invention. The PiN unit and a radioisotope unit located on the PiN unit.
The PiN unit comprises an N-type doped 4H-SiC substrate 1, an N-type doped 4H-SiC epitaxial layer 2, a P-type ion implantation region 3, an N-type ohmic contact electrode 4, a first passivation layer 5, a second passivation layer 6 and a P-type ohmic contact electrode 7.
Specifically, the shape of the PiN cell includes, but is not limited to, square or circular. When the Pin unit is square, the area of the table surface is 0.5x0.5cm-1.0x1.0 cm; when the Pin unit is round, the table surface area is phi 0.5 cm-phi 1.0cm; the area size of the PiN cell is not limited to the above area and size.
The N-type ohmic contact electrode 4, the N-type doped 4H-SiC substrate 1 and the N-type doped 4H-SiC epitaxial layer 2 are laminated in this order. Forming an isolation table-board on the outer peripheral side of part of the N-type doped 4H-SiC epitaxial layer 2; specifically, the isolation mesa is formed on the side surface of the partial N-doped 4H-SiC epitaxial layer 2 and the outer peripheral surface of the N-doped 4H-SiC epitaxial layer 2.
In one embodiment, the material of the N-type doped 4H-SiC substrate 1 is N-type highly doped 4H-SiC with a doping concentration of 5×10 18 cm -3 The thickness was 380. Mu.m. The material of the N-type doped 4H-SiC epitaxial layer 2 is N-type low-doped 4H-SiC, and the doping concentration is 1 multiplied by 10 14 ～1×10 15 cm -3 The thickness is 4.0-10.0 mu m, and the doping ion is nitrogen ion. The material of the N-type ohmic contact electrode 4 includes, but is not limited to, ni, 200nm thick; ohmic contact is formed between the N-type ohmic contact electrode 4 and the interface of the N-type doped 4H-SiC substrate 1.
The P-type ion implantation region 3 is positioned in the surface layer of the N-type doped 4H-SiC epitaxial layer 2 to form a distributed P-type region; the distributed P-type region may be a gate-like distributed P-type region and a ring-like distributed P-type region. Specifically, the P-type ion implantation region 3 is formed by ion implantation of an N-type doped 4H-SiC epitaxial layer 2 having a doping concentration of 1×10 19 ～5×10 19 cm -3 The implantation depth is 0.2-0.5 mu m, the width is 10-20 mu m, and the implanted ions are aluminum ions; the interval between adjacent implantation regions in the distributed P-type ion implantation region 3 is 100-1000 μm.
The first passivation layer 5 is located on the N-type doped 4H-SiC epitaxial layer 2 and covers the surface of the isolation mesa, i.e., the surface and sides of the N-type doped 4H-SiC epitaxial layer 2 between the P-type ion implantation regions 3. Specifically, the material of the first passivation layer 5 includes SiO 2 The thickness is 30-50 nm, and the width of the first passivation layer 5 positioned between the P-type ion implantation regions 3, namely between the P-type ohmic contact electrodes 7, is equal to the interval between the adjacent implantation regions in the distributed P-type ion implantation regions 3, and is 100-1000 mu m.
The second passivation layer 6 is located on the first passivation layer 5 at the isolation mesa, i.e. the second passivation layer 6 is located on the outer surface of the first passivation layer 5. Specifically, the thickness of the second passivation layer 6 is 0.2 to 0.5 μm and the side height is 1 μm.
The P-type ohmic contact electrode 7 is located on the P-type ion implantation region 3 and is spaced apart from the first passivation layer 5. It is understood that the P-type ohmic contact electrode 7 completely covers the P-type ion implantation region 3, and the first passivation layer 5 is the other portion. The shape of the P-type ohmic contact electrode 7 is the same as that of the P-type ion implantation region 3, forming a distributed ohmic contact electrode. The material of the P-type ohmic contact electrode 7 includes, but is not limited to, one or more of Ti, ni, and Al, for example, the material of the P-type ohmic contact electrode 7 is Ti, or Ni, or Al, or a combination of Ti and Ni, or a combination of Ti and Al, or a combination of Ni and Al, or a multilayer metal of a combination of Ti and Ni and Al; the thickness of the P-type ohmic contact electrode 7 is 50-150 nm, and the width is 10-20 mu m; ohmic contact is formed between the P-type ohmic contact electrode 7 and the interface of the P-type ion implantation region 3.
The radioisotope unit is located above the first passivation layer 5 and the P-type ohmic contact electrode 7. Specifically, the radioisotope unit includes a radioisotope source layer 8, the radioisotope source layer 8 is located above the first passivation layer 5 and the P-type ohmic contact electrode 7, and the beta-radiation source material of the radioisotope source layer 8 includes Ni 63 、Pm 137 、H 3 But are not limited to, these several isotopes.
Referring to fig. 3, fig. 3 is a schematic structural diagram of a gate P-type ohmic contact electrode according to an embodiment of the present invention.
In fig. 3, the P-type ohmic contact electrode 7 is a grid-shaped distribution electrode, and includes a plurality of longitudinal rectangular bars 71 and a plurality of transverse rectangular bars 72, wherein the longitudinal rectangular bars 71 are arranged in parallel, the transverse rectangular bars 72 are arranged in parallel, and each transverse rectangular bar 72 is connected with the longitudinal rectangular bars 71. It will be appreciated that the transverse rectangular bars 72 may be connected in the middle of the longitudinal rectangular bars 71 or may be connected at the ends of the longitudinal rectangular bars 71.
Further, the plurality of longitudinal rectangular bars 71 are equally spaced apart, and the plurality of transverse rectangular bars 72 are equally spaced apart and vertically bisect the longitudinal rectangular bars 71.
In one embodiment, the plurality of longitudinal rectangular bars 71 are equally spaced, have the same length as the longitudinal length of the PiN unit, have a width of 10 μm to 20 μm, and have a number of 5 or more; the spacing h1 between the longitudinal rectangular bars 71 is 100-1000 μm the same as the spacing between the adjacent implanted regions and the width of the first passivation layer 5 between the P-type ohmic contact electrodes 7. The transverse rectangular strips 72 vertically divide the longitudinal rectangular strips 71, the length of the strips is the same as the transverse length of the PiN units, the width of the strips is 10-20 mu m, and the number of the strips is more than or equal to 1.
Referring to fig. 4, fig. 4 is a schematic structural diagram of an annular P-type ohmic contact electrode according to an embodiment of the present invention.
In fig. 4, the P-type ohmic contact electrode 7 is an annular distribution electrode, and includes a plurality of rings 73 and a plurality of rectangular strips 74, wherein the rings 73 are sequentially nested in order from small to large in radius, and each rectangular strip 74 is connected with the rings 73. Further, the rings 73 are concentric circles distributed at equal intervals, and the ring intervals are equal to the inner diameter of the central ring 73; the rectangular strips 74 are equiangularly distributed, that is, the included angles between the adjacent rectangular strips 74 are equal, and the rectangular strips 74 are uniformly distributed along the circumference of the circular ring 73.
In one embodiment, the plurality of rings 73 are concentric circles, the width of the rings 73 is 10 μm to 20 μm, the plurality of rings 73 are distributed at equal intervals, the ring intervals are equal to the inner diameter of the central ring 73, and the number of the rings 73 is greater than or equal to 5; the ring spacing h2, the inner diameter h3 of the central ring 73, the spacing between adjacent injection regions and the width of the first passivation layer 5 between the P-type ohmic contact electrodes 7 are all the same and are 100-1000 μm. The rings are connected by a plurality of rectangular bars 74, and a plurality of two rectangular bars 74 are equiangularly distributed, for example, when the number of rectangular bars 74 is equal to 4, the included angles between two adjacent rectangular bars 74 are 90 °.
The shape of the P-type ohmic contact electrode 7 is not limited to the above-described grid-like distributed electrode and annular distributed electrode, as long as it satisfies the conditions of the distributed electrode.
Compared with a conventional silicon carbide PiN type beta irradiation battery, in the embodiment, the distributed P type region is obtained by carrying out ion implantation on the N type doped 4H-SiC epitaxial layer, an ohmic contact electrode is covered only above the distributed P type region, and passivation treatment is carried out on the surface of the N type epitaxial layer outside the distributed P type region, so that the surface of the N type epitaxial layer is covered with SiO 2 And a first passivation layer. This has the following advantages: 1. the distributed P-type region is obtained by carrying out ion implantation treatment on the N-type epitaxial layer, compared with the process method of carrying out P-type epitaxy on the surface of the N-type epitaxial layer and carrying out groove etching on the P-type epitaxial layer to obtain the distributed P-type region, the surface damage of the N-type epitaxial layer caused by surface etching is avoided, the composite action of the surface of the N-type region is reduced, and meanwhile, the planar device obtained by the ion implantation process is beneficial to the transverse expansion of a depletion region electric field generated by the distributed P-type region in the N-type epitaxial layer, so that the collection efficiency of carriers is improved, and the saturation current is reduced. 2. The distributed P-type region and the ohmic contact electrode above the distributed P-type region reduce the P-type dead zone on the surface of the device and the coverage area of the corresponding metal electrode, so that the energy loss of the P-type dead zone on beta rays caused by the ohmic contact electrode and the P-type dead zone is reduced, the recombination of carriers at a P-type dead zone and a metal contact interface is reduced, meanwhile, the average transport distance in the carrier collection process is reduced through the pattern design of the distributed P-type region and the corresponding ohmic contact electrode above the distributed P-type region, the recombination loss of carriers in the transport process is reduced, and the collection efficiency of the carriers is improved. 3. Because the collecting efficiency of the P-type region on carriers is far lower than that of the depletion region, the conventional silicon carbide PiN-type beta irradiation battery mainly uses a PN junction to form the depletion region as a part of a sensitive region to collect carriers generated by beta ray irradiation, so that incident beta rays must pass through the P-type dead layer region, thereby causing remarkable particle energy loss; in the present embodiment, the distributed P-type region is formed only in the ion implantation region by ion implantation treatment, and is formed by SiO 2 The negative fixed charges of the silicon carbide interface between the first passivation layer and the N-type epitaxial layer replace the P-type region to generate a surface depletion region of the N-type epitaxial layer and a P-type inversion layer on the surface of the N-type epitaxial layer, so that beta rays can deposit energy on the depletion layer without passing through the P-type dead layer region, and the collection efficiency of carriers is improved. SiO on the surface of the N-type epitaxial layer 2 The first passivation layer improves interface characteristics, reduces the recombination effect of the surface of the device, simultaneously the depletion region electric field on the surface of the N-type epitaxial layer withdraws electrons generated by beta rays, and a P-type inversion layer is formed on the surface, so that the recombination effect of the surface of the device is further reduced, and the carrier recombination loss is reducedAnd reduces the device saturation current. The short-circuit current Isc can be raised at the 2 nd and 3 rd points, and the short-circuit current Isc, the open-circuit voltage Voc and the filling factor FF can be raised at the 1 st and 4 th points, so that the energy conversion efficiency of the beta-irradiation battery can be finally raised.
In summary, in the irradiation battery of this embodiment, a distributed P-type ion implantation region is formed in the surface layer of the N-type doped 4H-SiC epitaxial layer, and a P-type ohmic contact electrode is prepared on the distributed P-type region, and meanwhile, the surface outside the P-type region is subjected to passivation layer treatment, so that the surface of the N-type epitaxial layer covers the first passivation layer, the energy deposition of beta rays in the P-type region is reduced, the surface recombination effect of the device is weakened, the collection efficiency of the ohmic contact electrode on carriers generated by irradiation is improved, the recombination of the carriers generated by irradiation in the transportation process is reduced, the saturation current of the device is reduced, and further the short-circuit current Isc, the open-circuit voltage Voc and the filling factor FF are improved, so that the energy conversion efficiency of the beta irradiation battery is improved.
Example two
On the basis of the first embodiment, please refer to fig. 5 a-5 j, fig. 5 a-5 j are schematic process diagrams of a preparation method of a planar PiN type β -irradiation battery with a passivation layer surface field according to an embodiment of the present invention, the preparation method includes the steps of:
s1, epitaxially growing an N-type doped 4H-SiC epitaxial layer 2 on an N-type doped 4H-SiC substrate 1, see FIG. 5a and FIG. 5b.
First, the sample wafer of the N-type doped 4H-SiC substrate 1 is cleaned to remove surface pollutants.
Then, epitaxially growing a layer of 1X 10 doping concentration on the surface of the cleaned N-type high doping 4H-SiC substrate 1 sample wafer by using a chemical vapor deposition CVD method 14 ～1×10 15 cm -3 N-type low doped 4H-SiC with the thickness of 4.0-10.0 mu m is formed into an N-type doped 4H-SiC epitaxial layer 2.
S2, carrying out mesa etching on the N-type doped 4H-SiC epitaxial layer 2 to form an isolation mesa, see FIG. 5c.
Specifically, the N-type doped 4H-SiC epitaxial layer 2 is subjected to mesa etching by using an inductively coupled plasma ICP etching method, the etching depth is 1 mu m, so that part of the N-type doped 4H-SiC epitaxial layer 2 forms a mesa, and mesa isolation of a device is formed.
S3, performing ion implantation in the surface layer of the N-type doped 4H-SiC epitaxial layer 2 to form a distributed P-type ion implantation region 3, see FIG. 5d.
Specifically, a silicon dioxide ion implantation mask layer is deposited on the surface of a sample, glue is coated on the silicon dioxide ion implantation mask layer, a blocking layer with a distributed P-type region pattern is formed by photoetching, an ion implantation window is opened by etching silicon dioxide by an acid wet method, and a doping concentration of 1 multiplied by 10 is formed on the upper part of an N-type doped 4H-SiC epitaxial layer 2 by adopting an ion implantation method 19 ～5×10 19 cm -3 And the P-type ion implantation region with the depth of 0.2-0.5 mu m is subjected to 1700 ℃ high temperature thermal annealing under the protection of a surface carbon film, so that the distributed P-type ion implantation region 3 is formed.
S4, preparing a first passivation layer 5 on the surface of the N-type doped 4H-SiC epitaxial layer 2 and the surface of the isolation mesa, see FIG. 5e.
Specifically, the sample subjected to ion implantation is subjected to sacrificial oxidation, the surface sacrificial oxidation layer is removed by etching silicon dioxide by an acid wet method, the sample is cleaned, and then the sample is subjected to high-temperature thermal oxidation to form a dense SiO2 passivation thin layer with the thickness of 30-50 nm, so that the first passivation layer 5 is formed.
S5, preparing a second passivation layer 6 on the first passivation layer 5 at the isolation mesa, see FIG. 5f.
In particular, in dense SiO 2 Coating adhesive on the passivation layer, photoetching to form a barrier layer with sensitive region pattern, and forming a dense SiO (silicon dioxide) 2 Performing CVD deposition on the surface of the passivation thin layer to passivate the sample wafer, and performing dense SiO (silicon dioxide) 2 The surface of the passivation thin layer forms SiO with the thickness of 0.2-0.5 mu m 2 And a passivation layer forming a second passivation layer 6.
S6, preparing a P-type ohmic contact electrode 7 on the P-type ion implantation region 3, so that the P-type ohmic contact electrode 7 and the first passivation layer 5 are arranged alternately.
First, a photoresist is coated on the first passivation layer 5, a barrier layer with a distributed P-type region pattern is formed by photolithography, and an acid wet etching silicon dioxide is used to open a window of the first passivation layer 5 as a P-type ohmic contact electrode region 7', see fig. 5g.
Then, glue is coated on the front surface of the sample wafer, a metal deposition window on the surface of the distributed P-type region is formed by photoetching, the sample wafer after windowing is cleaned, P-type ohmic contact electrode metal is deposited by magnetron sputtering, the material is Ti or Ni or Al or multilayer metal containing Ti or Ni or Al, and then photoresist is stripped to form the P-type ohmic contact electrode 7, see FIG. 5h.
S7, epitaxially growing an N-type ohmic contact electrode 4 on the back surface of the N-type doped 4H-SiC substrate 1, see FIG. 5i.
And coating glue on the front surface of the sample wafer for protection, and forming an N-type ohmic contact electrode 4 on the back surface of the sample wafer through magnetron sputtering deposition, wherein the N-type ohmic contact electrode 4 is made of Ni, and the thickness is 200nm.
S8, a radioisotope unit is prepared above the first passivation layer 5 and the P-type ohmic contact electrode 7, see fig. 5j.
Specifically, a radioisotope source layer 8 is formed on the upper surface of a sample by a deposition or painting method, and a planar silicon carbide Pin type beta irradiation battery with a distributed P type region and a passivation layer surface field is obtained.
The device structure manufactured by the above manufacturing method is referred to in embodiment one, and this embodiment is not repeated.
The irradiation battery prepared by the embodiment forms the distributed P-type ion implantation region in the surface layer of the N-type doped 4H-SiC epitaxial layer, prepares the P-type ohmic contact electrode on the distributed P-type region, and simultaneously carries out passivation layer treatment on the surface outside the P-type region, so that the surface of the N-type epitaxial layer is covered with the first passivation layer, the energy deposition of beta rays in the P-type region is reduced, the surface recombination effect of a device is weakened, the collection efficiency of the ohmic contact electrode on carriers generated by irradiation is improved, the recombination of the carriers generated by irradiation in the transportation process is reduced, the saturation current of the device is reduced, and further the short-circuit current Isc, the open-circuit voltage Voc and the filling factor FF are improved, and the purpose of improving the energy conversion efficiency of the beta irradiation battery is achieved.
Example III
On the basis of the second embodiment, please refer to fig. 5 a-5 j, the preparation method of the planar silicon carbide PiN type beta irradiation cell with grid-shaped distributed P-type region and passivation layer surface field is described in this embodiment, wherein the cell area is 0.7cm×0.7cm, the pitch of the P-type implantation region is 300 μm, the number of electrodes of the longitudinal rectangular strips 71 is 22, and the number of electrodes of the transverse rectangular strips 72 is 1.
S1, epitaxially growing an N-type doped 4H-SiC epitaxial layer 2 on an N-type doped 4H-SiC substrate 1.
First, a standard RAC is used to clean a sample of the N-doped 4H-SiC substrate 1 to remove surface contaminants, see fig. 5a.
Specifically, the doping concentration is 5×10 at 25deg.C 18 cm -3 N-type high doped 4H-SiC substrate 1 sample wafer with thickness of 380 mu m is arranged on H 2 SO 4 :H 2 O 2 Soaking in the reagent in the ratio of (4:1) for 10min to remove organic and metal contamination on the surface of the sample wafer; then at 85 ℃, the sample wafer with the surface organic and metal contamination removed is treated with H 2 O:NH 4 OH:H 2 O 2 Soaking in the reagent of (5:1:1) for 10min to remove impurity particles; thereafter, at 85 ℃, the sample wafer from which the impurity particles were removed was subjected to H 2 O:HCl:H 2 O 2 Soaking in the reagent of (5:1:1) for 10min to remove metal and heavy ion contamination; finally, at 25 ℃, the sample wafer with the metal removed and heavy ion contaminated is treated with H 2 O is soaked in a reagent of HF (10:1) for 10min to remove the surface natural oxide layer.
Then, an N-doped 4H-SiC epitaxial layer 2 is epitaxially grown, see fig. 5b.
Specifically, the N-type 4H-SiC low-doped epitaxial layer 2 is grown on the cleaned N-type high-doped 4H-SiC substrate 1 sample wafer by using a low pressure chemical vapor deposition LPCVD method in an unintended doping epitaxial mode. The process conditions are as follows: the epitaxy temperature was 1580deg.C and the pressure was 100mbar, the reaction gas was propane (C 3 H 8 ) And Silane (SiH) 4 ) C/Si is 1, carrier gas is pure hydrogen, and the doping concentration of nitrogen is 7 multiplied by 10 14 cm -3 The N-type 4H-SiC low doped epitaxial layer 2 has a thickness of 9 μm.
S2, carrying out mesa etching on the N-type doped 4H-SiC epitaxial layer 2 to form an isolation mesa, see FIG. 5c.
Firstly, carrying out standard RCA cleaning on a sample wafer subjected to epitaxial growth; after the sample wafer is washed, the nitrogen doping concentration is 7×10 14 cm -3 A Ni film with the thickness of 200nm is deposited on the N-doped 4H-SiC epitaxial layer 2 through magnetron sputtering as an etching mask layer, and the Ni film is patterned by using a photoetching plate to form patterns required by etching; then etching part of the N-doped 4H-SiC epitaxial layer 2 on the upper surface of the sample wafer by utilizing inductively coupled plasma ICP with the etching depth of 1 mu m, and using H at 25 DEG C 2 SO 4 :H 2 O 2 (4:1) immersing the sample wafer subjected to the etching for 10min to remove the Ni mask layer, so as to form the mesa isolation of the device.
S3, performing ion implantation in the surface layer of the N-type doped 4H-SiC epitaxial layer 2 to form a distributed P-type ion implantation region 3, see FIG. 5d.
Firstly, carrying out standard RCA cleaning on a sample wafer subjected to mesa etching; then, using chemical vapor deposition CVD to deposit silicon dioxide with the thickness of 3 mu m on the surface of the sample wafer as an ion implantation mask layer; then spin coating photoresist on the silicon dioxide ion implantation mask layer, photoetching to form a barrier layer with a distributed P-type region pattern, and etching the silicon dioxide by using a buffer HF solution BHF acid wet method with the concentration of 5% to open an ion implantation window; then, ion implantation is carried out on the N-type doped 4H-SiC epitaxial layer 2 to form a grid-shaped distributed P-type ion implantation region 3 with the doping concentration of 1.5x10 19 cm -3 The implantation depth was 0.3 μm, the width was 16 μm, the pitch was 300 μm, and the ion implantation parameters were: p-type injected impurities are monovalent aluminum ions, the energy of the aluminum ions is less than or equal to 350KeV, and the injection temperature is 400 ℃; finally, the silicon dioxide ion implantation mask layer is removed by adopting a buffer HF solution BHF acid wet etching with the concentration of 5 percent for the sample wafer after ion implantation, then the physical vapor deposition PVD is carried out for the surface of the sample wafer to deposit a carbon film protection layer, and the high temperature thermal annealing is carried out for 20 minutes at the temperature of 1700 ℃.
S4, preparing a first passivation layer 5 on the surface of the N-type doped 4H-SiC epitaxial layer 2 and the surface of the isolation mesa, see FIG. 5e.
Firstly, carrying out standard RCA cleaning on a sample wafer after ion implantation; then, carrying out wet oxygen oxidation on the surface of the sample piece for 2 hours at 1150+/-50 ℃ to form a sacrificial oxide layer; then, carrying out wet etching on the sample wafer subjected to sacrificial oxidation by adopting HF solution DHF acid with the concentration of 10% to remove a sacrificial oxide layer; then, carrying out standard RCA cleaning on the sample wafer from which the sacrificial oxide layer is removed; finally, dry oxidation is carried out on the surface of the sample piece after ion implantation for 3 hours at 1150+/-50 ℃ to form compact SiO with the thickness of 30nm 2 The thin layer was passivated, and then annealed in a nitrogen atmosphere at 1150±50 ℃ for 1 hour, to form the first passivation layer 5.
S5, preparing a second passivation layer 6 on the first passivation layer 5 at the isolation mesa, see FIG. 5f.
Firstly, spin coating photoresist on the first passivation layer 5; then, patterning the photoresist by using a photolithography mask to form a barrier layer having a pattern of a sensitive region; finally, at a temperature of 250 ℃, a plasma enhanced chemical vapor deposition PECVD method is used to deposit SiO with a thickness of 300nm on the first passivation layer 5 2 Then, a rapid thermal annealing is performed in a pure argon atmosphere at a temperature of 1000±50 ℃ for 5 minutes to form the second passivation layer 6.
S6, preparing a P-type ohmic contact electrode 7 on the P-type ion implantation region 3, so that the P-type ohmic contact electrode 7 and the first passivation layer 5 are arranged alternately.
First, the first passivation layer 5 is etched and windowed to form a P-type ohmic contact electrode region 7', see fig. 5g. Specifically, photoresist is spin-coated on the first passivation layer 5, the photoresist is patterned by using a photolithography plate, a barrier layer with a distributed P-type region pattern required by etching and windowing is formed, then a buffer HF solution BHF with the concentration of 5% is used for etching silicon dioxide in a wet method to open a window of the first passivation layer 5, and the windowed region is used as a P-type ohmic contact electrode region.
Then, a gate-like distributed P-type ohmic contact electrode 7 for the sensitive region is formed, see fig. 5h. Specifically, photoresist is firstly coated on the front surface of a sample wafer in a spin mode; patterning the photoresist by using a photoetching plate to form a metal deposition window on the surface of the distributed P-type region; then cleaning the surface of the windowed sample wafer by a wet method and a dry method, and depositing Ti/Al double-layer metal with the thickness of 30nm/70nm respectively by magnetron sputtering to form contact metal of a P-type ohmic contact electrode; finally, stripping the photoresist to form grid-shaped distributed P-type ohmic contact electrodes 7 with electrode widths (namely the widths of the longitudinal rectangular strips and the transverse rectangular strips) of 16 mu m, electrode spacing of 300 mu m between the longitudinal rectangular strips, the number of electrodes 22 of the longitudinal rectangular strips 71 and the number of electrodes 1 of the transverse rectangular strips 72.
S7, epitaxially growing an N-type ohmic contact electrode 4 on the back surface of the N-type doped 4H-SiC substrate 1, see FIG. 5i.
First, photoresist is spin-coated on the front surface of the sample wafer. Then, the surface of the sample was cleaned by wet or dry method. Then, ni metal with a thickness of 200nm was deposited on the lower surface of the sample piece by magnetron sputtering to form an N-type ohmic contact electrode 4. Finally, rapid thermal annealing is performed under pure argon atmosphere at 1000 ℃ for 3 minutes, and an ohmic contact interface of the N-type ohmic contact electrode 4 and the P-type ohmic contact electrode 7 is formed.
S8, a radioisotope unit is prepared above the first passivation layer 5 and the P-type ohmic contact electrode 7, see fig. 5j.
Specifically, a beta radiation source is placed on the upper surface of a sample by a deposition or painting method to form a radioisotope source layer 8, so that the planar silicon carbide PiN type beta irradiation battery with a grid-shaped distributed P-type region and a passivation layer surface field is obtained.
Example IV
On the basis of the second embodiment, please refer to fig. 5 a-5 j, the preparation method of the planar silicon carbide PiN type beta irradiation cell with annular distributed P-type region and passivation layer surface field is described in this embodiment, wherein the cell area Φ0.8cm, the interval between P-type implantation regions 900 μm, the number of ring electrodes 8, and the number of rectangular strip 74 electrodes 4.
S1, epitaxially growing an N-type doped 4H-SiC epitaxial layer 2 on an N-type doped 4H-SiC substrate 1.
First, a standard RAC is used to clean a sample of the N-doped 4H-SiC substrate 1 to remove surface contaminants, see fig. 5a.
Specifically, the doping concentration is 5×10 at 25deg.C 18 cm -3 N-type high doped 4H-SiC substrate 1 sample wafer with thickness of 380 mu m is arranged on H 2 SO 4 :H 2 O 2 Soaking in the reagent in the ratio of (4:1) for 10min to remove organic and metal contamination on the surface of the sample wafer; then at 85 ℃, the sample wafer with the surface organic and metal contamination removed is treated with H 2 O:NH 4 OH:H 2 O 2 Soaking in the reagent of (5:1:1) for 10min to remove impurity particles; thereafter, at 85 ℃, the sample wafer from which the impurity particles were removed was subjected to H 2 O:HCl:H 2 O 2 Soaking in the reagent of (5:1:1) for 10min to remove metal and heavy ion contamination; finally, at 25 ℃, the sample wafer with the metal removed and heavy ion contaminated is treated with H 2 O is soaked in a reagent of HF (10:1) for 10min to remove the surface natural oxide layer.
Then, an N-doped 4H-SiC epitaxial layer 2 is epitaxially grown, see fig. 5b.
Specifically, the N-type low-doped 4H-SiC epitaxial layer 2 is grown on the cleaned N-type high-doped 4H-SiC substrate 1 sample wafer by using a low pressure chemical vapor deposition LPCVD method in an unintended doping epitaxial mode. The process conditions are as follows: the epitaxy temperature was 1580deg.C and the pressure was 100mbar, the reaction gas was propane (C 3 H 8 ) And Silane (SiH) 4 ) C/Si is 1.5, carrier gas is pure hydrogen, and nitrogen doping concentration is 1X 10 14 cm -3 An N-type low doped 4H-SiC epitaxial layer 2 with a thickness of 10 μm.
S2, carrying out mesa etching on the N-type doped 4H-SiC epitaxial layer 2 to form an isolation mesa, see FIG. 5c.
Firstly, carrying out standard RCA cleaning on a sample wafer subjected to epitaxial growth; after the sample wafer is washed, the nitrogen doping concentration is 1X 10 14 cm -3 A Ni film with the thickness of 200nm is deposited on the N-doped 4H-SiC epitaxial layer 2 through magnetron sputtering as an etching mask layer, and the Ni film is patterned by using a photoetching plate to form patterns required by etching; then etching part of the N-doped 4H-SiC epitaxial layer 2 on the upper surface of the sample wafer by utilizing inductively coupled plasma ICP with the etching depth of 1 mu m, and using H at 25 DEG C 2 SO 4 :H 2 O 2 (4:1) immersing the sample wafer subjected to the etching for 10min to remove the Ni mask layer, so as to form the mesa isolation of the device.
S3, performing ion implantation in the surface layer of the N-type doped 4H-SiC epitaxial layer 2 to form a distributed P-type ion implantation region 3, see FIG. 5d.
Firstly, carrying out standard RCA cleaning on a sample wafer subjected to mesa etching; then, using chemical vapor deposition CVD to deposit silicon dioxide with the thickness of 3 mu m on the surface of the sample wafer as an ion implantation mask layer; then spin coating photoresist on the silicon dioxide ion implantation mask layer, photoetching to form a barrier layer with a distributed P-type region pattern, and etching the silicon dioxide by using a buffer HF solution BHF acid wet method with the concentration of 5% to open an ion implantation window; then, ion implantation is carried out on the N-type doped 4H-SiC epitaxial layer 2 to form a ring-shaped distributed P-type ion implantation region 3, and the doping concentration is 3 multiplied by 10 19 cm -3 The implantation depth was 0.25 μm, the width was 12 μm, the pitch was 900 μm, and the ion implantation parameters were: p-type injected impurities are monovalent aluminum ions, the energy of the aluminum ions is less than or equal to 350KeV, and the injection temperature is 400 ℃; finally, the silicon dioxide ion implantation mask layer is removed by adopting a buffer HF solution BHF acid wet etching with the concentration of 5 percent for the sample wafer after ion implantation, then the physical vapor deposition PVD is carried out for the surface of the sample wafer to deposit a carbon film protection layer, and the high temperature thermal annealing is carried out for 20 minutes at the temperature of 1700 ℃.
S4, preparing a first passivation layer 5 on the surface of the N-type doped 4H-SiC epitaxial layer 2 and the surface of the isolation mesa, see FIG. 5e.
Firstly, carrying out standard RCA cleaning on a sample wafer after ion implantation; then, carrying out wet oxygen oxidation on the surface of the sample piece for 2 hours at 1150+/-50 ℃ to form a sacrificial oxide layer; then, carrying out wet etching on the sample wafer subjected to sacrificial oxidation by adopting HF solution DHF acid with the concentration of 10% to remove a sacrificial oxide layer; then, carrying out standard RCA cleaning on the sample wafer from which the sacrificial oxide layer is removed; finally, dry oxidation is carried out on the surface of the sample piece after ion implantation for 4 hours at 1150+/-50 ℃ to form compact SiO with the thickness of 40nm 2 Passivating the thin layer, and then annealing in nitrogen atmosphere at 1150+ -50deg.C for 1 hr to form a firstAnd a passivation layer 5.
S5, preparing a second passivation layer 6 on the first passivation layer 5 at the isolation mesa, see FIG. 5f.
Firstly, spin coating photoresist on the first passivation layer 5; then, patterning the photoresist by using a photolithography mask to form a barrier layer having a pattern of a sensitive region; finally, at a temperature of 250 ℃, a plasma enhanced chemical vapor deposition PECVD method is used to deposit SiO with a thickness of 400nm on the first passivation layer 5 2 Then, a rapid thermal annealing is performed in a pure argon atmosphere at a temperature of 1000±50 ℃ for 5 minutes to form the second passivation layer 6.
S6, preparing a P-type ohmic contact electrode 7 on the P-type ion implantation region 3, so that the P-type ohmic contact electrode 7 and the first passivation layer 5 are arranged alternately.
First, the first passivation layer 5 is etched and windowed to form a P-type ohmic contact electrode region 7', see fig. 5g. Specifically, photoresist is spin-coated on the first passivation layer 5, the photoresist is patterned by using a photolithography plate, a barrier layer with a distributed P-type region pattern required by etching and windowing is formed, then a buffer HF solution BHF with the concentration of 5% is used for etching silicon dioxide in a wet method to open a window of the first passivation layer 5, and the windowed region is used as a P-type ohmic contact electrode region.
Then, a gate-like distributed P-type ohmic contact electrode 7 for the sensitive region is formed, see fig. 5h. Specifically, photoresist is firstly coated on the front surface of a sample wafer in a spin mode; patterning the photoresist by using a photoetching plate to form a metal deposition window on the surface of the distributed P-type region; then cleaning the surface of the windowed sample wafer by a wet method and a dry method, and depositing Ni metal with the thickness of 120nm respectively by magnetron sputtering to form contact metal of a P-type ohmic contact electrode; finally, stripping the photoresist to form annular distributed P-type ohmic contact electrodes 7 with electrode widths, namely the widths of the circular rings and the rectangular strips, of 12 mu m, the spacing between the rings of the electrodes of 900 mu m, the number of the circular ring electrodes of 8 and the number of the rectangular strips 74 of 4.
S7, epitaxially growing an N-type ohmic contact electrode 4 on the back surface of the N-type doped 4H-SiC substrate 1, see FIG. 5i.
First, photoresist is spin-coated on the front surface of the sample wafer. Then, the surface of the sample was cleaned by wet or dry method. Then, ni metal with a thickness of 200nm was deposited on the lower surface of the sample piece by magnetron sputtering to form an N-type ohmic contact electrode 4. Finally, rapid thermal annealing is performed under pure argon atmosphere at 1000 ℃ for 3 minutes, and an ohmic contact interface of the N-type ohmic contact electrode 4 and the P-type ohmic contact electrode 7 is formed.
S8, a radioisotope unit is prepared above the first passivation layer 5 and the P-type ohmic contact electrode 7, see fig. 5j.
Specifically, a beta radiation source is placed on the upper surface of a sample by a deposition or painting method to form a radioisotope source layer 8, so that the planar silicon carbide PiN type beta irradiation battery with a grid-shaped distributed P-type region and a passivation layer surface field is obtained.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.
Claims (10)
1. A planar PiN type beta irradiation battery with a passivation layer surface field is characterized by comprising a PiN unit and a radioisotope unit positioned on the PiN unit, wherein the PiN unit comprises an N type doped 4H-SiC substrate (1), an N type doped 4H-SiC epitaxial layer (2), a P type ion implantation region (3), an N type ohmic contact electrode (4), a first passivation layer (5), a second passivation layer (6) and a P type ohmic contact electrode (7),
the N-type ohmic contact electrode (4), the N-type doped 4H-SiC substrate (1) and the N-type doped 4H-SiC epitaxial layer (2) are sequentially laminated, and an isolation table top is arranged on the peripheral side of the N-type doped 4H-SiC epitaxial layer (2);
the P-type ion implantation region (3) is positioned in the surface layer of the N-type doped 4H-SiC epitaxial layer (2) to form a distributed P-type region;
the first passivation layer (5) is positioned on the N-type doped 4H-SiC epitaxial layer (2) and covers the surface of the isolation mesa;
-the second passivation layer (6) is located on the first passivation layer (5) at the isolation mesa;
the P-type ohmic contact electrode (7) is positioned on the P-type ion implantation region (3) and is arranged at intervals with the first passivation layer (5);
the radioisotope unit is located above the first passivation layer (5) and the P-type ohmic contact electrode (7).
2. Planar PiN-type beta irradiation cell with passivation layer surface field according to claim 1, characterized in that the doping concentration of the P-type ion implantation region (3) is 1 x 10 19 ～5×10 19 cm -3 The implantation depth is 0.2-0.5 mu m, the width is 10-20 mu m, and the interval between adjacent implantation regions in the P-type ion implantation region (3) is 100-1000 mu m.
3. The planar PiN-type beta irradiation cell with passivation layer surface field according to claim 1, wherein the P-type ohmic contact electrode (7) comprises a plurality of longitudinal rectangular strips (71) and a plurality of transverse rectangular strips (72), the plurality of longitudinal rectangular strips (71) are arranged side by side, the plurality of transverse rectangular strips (72) are arranged side by side and each transverse rectangular strip (72) is connected with the plurality of longitudinal rectangular strips (71).
4. A planar PiN-type beta irradiation cell with passivation layer surface field according to claim 3, characterized in that several of the longitudinal rectangular strips (71) are equally spaced apart, several of the transverse rectangular strips (72) are equally spaced apart and the longitudinal rectangular strips (71) are equally vertically divided.
5. A planar PiN-type beta irradiation cell with passivation layer surface field according to claim 3, characterized in that the number of longitudinal rectangular strips (71) is greater than or equal to 5 and the number of transverse rectangular strips (72) is greater than or equal to 1; the width of the longitudinal rectangular strips (71) and the width of the transverse rectangular strips (72) are 10-20 mu m, and the interval between the longitudinal rectangular strips (71) is 100-1000 mu m.
6. The planar PiN-type beta irradiation cell with passivation layer surface field according to claim 1, wherein the P-type ohmic contact electrode (7) comprises a plurality of circular rings (73) and a plurality of rectangular strips (74), the plurality of circular rings (73) are nested in sequence from the smaller radius to the larger radius, and each rectangular strip (74) is connected with the plurality of circular rings (73).
7. The planar PiN-type beta irradiation cell with passivation layer surface field according to claim 6, wherein the rings (73) are concentric circles distributed at equal intervals, the ring pitch is equal to the inner diameter of the central ring (73), and the rectangular bars (74) are distributed at equal angles.
8. The planar PiN-type beta irradiation cell with passivation layer surface field of claim 6, wherein the number of rings (73) is greater than or equal to 5 and the number of rectangular bars (74) is greater than or equal to 4; the width of the circular ring (73) and the width of the rectangular strip (74) are 10-20 mu m, and the ring spacing of the circular ring (73) and the inner diameter of the central circular ring (73) are 100-1000 mu m.
9. Planar PiN-type beta irradiation cell with passivation layer surface field according to claim 1, characterized in that the radioisotope unit comprises a radioisotope source layer (8), the radioisotope source layer (8) being located above the number of first passivation layers (5) and the P-type ohmic contact electrode (7).
10. The preparation method of the planar Pin type beta irradiation battery with the passivation layer surface field is characterized by comprising the following steps:
s1, epitaxially growing an N-type doped 4H-SiC epitaxial layer (2) on an N-type doped 4H-SiC substrate (1);
s2, carrying out mesa etching on the N-type doped 4H-SiC epitaxial layer (2) to form an isolation mesa;
s3, performing ion implantation in the surface layer of the N-type doped 4H-SiC epitaxial layer (2) to form a distributed P-type ion implantation region (3);
s4, preparing a first passivation layer (5) on the surface of the N-type doped 4H-SiC epitaxial layer (2) and the surface of the isolation mesa;
s5, preparing a second passivation layer (6) on the first passivation layer (5) at the isolation mesa;
s6, preparing a P-type ohmic contact electrode (7) on the P-type ion implantation region (3), so that the P-type ohmic contact electrode (7) and the first passivation layer (5) are arranged alternately;
s7, epitaxially growing an N-type ohmic contact electrode (4) on the back surface of the N-type doped 4H-SiC substrate (1);
s8, preparing a radioisotope unit above the first passivation layer (5) and the P-type ohmic contact electrode (7).
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0762499A1 (en) * | 1995-09-08 | 1997-03-12 | Daimler-Benz Aktiengesellschaft | Monolithic integrated device of PIN diode and field effect transistor and method of manufacturing the same |
| CN101540343A (en) * | 2009-04-14 | 2009-09-23 | 西安电子科技大学 | 4H-SiC PiN /schottky diode of offset field plate structure and manufacturing method of 4H-SiC PiN /schottky diode |
| CN102280157A (en) * | 2011-06-30 | 2011-12-14 | 西安电子科技大学 | Silicon carbide gridding electrode PIN type nuclear battery |
| WO2013056556A1 (en) * | 2011-10-19 | 2013-04-25 | 西安电子科技大学 | Layer i vanadium-doped pin-type nuclear battery and preparation method thereof |
| CN110491541A (en) * | 2018-10-29 | 2019-11-22 | 长安大学 | A kind of H-3 silicon carbide isotope battery and its manufacturing method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10304579B2 (en) * | 2017-01-25 | 2019-05-28 | Bor-Ruey Chen | PI-orbital semiconductor quantum cell |
-
2021
- 2021-10-09 CN CN202111177392.5A patent/CN113990550B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0762499A1 (en) * | 1995-09-08 | 1997-03-12 | Daimler-Benz Aktiengesellschaft | Monolithic integrated device of PIN diode and field effect transistor and method of manufacturing the same |
| CN101540343A (en) * | 2009-04-14 | 2009-09-23 | 西安电子科技大学 | 4H-SiC PiN /schottky diode of offset field plate structure and manufacturing method of 4H-SiC PiN /schottky diode |
| CN102280157A (en) * | 2011-06-30 | 2011-12-14 | 西安电子科技大学 | Silicon carbide gridding electrode PIN type nuclear battery |
| WO2013056556A1 (en) * | 2011-10-19 | 2013-04-25 | 西安电子科技大学 | Layer i vanadium-doped pin-type nuclear battery and preparation method thereof |
| CN110491541A (en) * | 2018-10-29 | 2019-11-22 | 长安大学 | A kind of H-3 silicon carbide isotope battery and its manufacturing method |
Non-Patent Citations (1)
| Title |
|---|
| 离子注入制备n型SiC欧姆接触的工艺研究;刘芳,张玉明,张义门,郭辉;半导体技术(第04期);全文 * |
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