Silicon carbide-based grid-shaped Schottky contact type nuclear battery

Abstract

The invention discloses a silicon carbide-based grid-shaped Schottky contact type nuclear battery and a manufacturing method thereof. The invention mainly solves the problems that in the prior art, a silicon carbide-based pn junction nuclear battery has difficult manufacturing process, and a Schottky junction nuclear battery has low efficiency. The nuclear battery of the invention sequentially comprises a bonding layer (1), a radioactive isotope source layer (3), a grid-shaped semitransparent Schottky contact layer (2), an n type SiC epitaxial layer (5) of which the doping concentration is 1*1015-5*1015cm<-3>, an n type SiC substrate (6) of which the doping concentration is 1*1018-7*1018cm<-3> and an ohmic contact electrode (7) from top to bottom, wherein a SiO2 passivation layer (4) is formed around the radioactive isotope source layer; the Schottky contact layer (2) comprises a horizontal grid bar and a plurality of vertical grid bars, wherein the horizontal grid bar is positioned in the middle position of each vertical grid bar; and the radioactive isotope source layer is positioned on the epitaxial layer (5) between every two vertical grid bars. The nuclear battery of the invention has the advantages of small energy loss and high energy conversion efficiency and can be used as an on-chip power source of an MEMS, a power source of a cardiac pacemaker or a spare power sourceof a mobile phone.

Description

technical field [0001] The invention belongs to the field of microelectronics, and in particular relates to a grid Schottky contact nuclear battery based on silicon carbide, which can be used to directly convert nuclear energy emitted by isotopes into electric energy. technical background [0002] In 1953, Rappaport discovered that the beta particles (β-Particles) produced by the decay of isotopes can generate electron-hole pairs in semiconductors. This phenomenon is called β-Voltaic Effect. Shortly thereafter, Elgin-Kidde first used the β-Voltaic Effect in power supply in 1957, and successfully manufactured the first isotope micro-battery (β-Voltaic Battery). Since 1989, GaN, GaP, AlGaAs, polysilicon and other materials have been used as materials for β-Voltaic batteries. With the advancement of the preparation and process technology of SiC, a wide bandgap semiconductor material, since 2006, there have been reports on SiC-based isotope batteries in the world. [0003] The...

AI Technical Summary

Problems solved by technology

In this PN junction structure, in order to prevent the ohmic contact electrode from blocking incident particles, the ohmic electrode must be overloaded in one corner of the device, but this will cause the irradiated carriers far away from the ohmic electrode to be recombined during the transport process, and Incident particles must pass through the SiO at the surface 2 The passivation layer and part of the P-type layer cause energy loss and reduce energy conversion efficiency

[0007] The nuclear battery disclosed in Chinese patent CN 101325093A adopts a Schottky junction structure, which avoids the difficulty in realizing the above-mentioned PN junction technology, but the Schottky contact layer of the Schottky nodule battery covers the entire battery area, as shown in Figure 8 As shown, since the incident particles reach the surface of the device, they will be blocked by the Schottky contact layer, only part of the particles can enter the device, and the particles entering the depletion region will contribute to the output power of the battery. Therefore, this The energy loss of the incident particles in the nuclear battery structure is large, and the energy conversion efficiency is low

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