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CN-119967823-B - Diode structure

CN119967823BCN 119967823 BCN119967823 BCN 119967823BCN-119967823-B

Abstract

The application provides a diode structure which comprises a substrate layer body, a filling groove, a filling layer body and a first metal layer body, wherein the substrate layer body comprises a top surface and a bottom surface which are oppositely arranged, the filling groove is arranged on the substrate layer body, the filling groove extends along the length direction or the width direction of the substrate layer body, the opening of the filling groove is gradually increased from the bottom surface to the top surface, the filling layer body is arranged in the filling groove, the filling layer body is provided with a first ohmic contact area in the filling groove, and the first metal layer body is arranged on the top surface of the substrate layer body and is in Schottky contact with the substrate layer body, and at least part of the first metal layer body is embedded in the filling groove. The application solves the problem of low high voltage resistance of SIC diode devices in the prior art.

Inventors

  • LI LI

Assignees

  • 珠海格力电子元器件有限公司
  • 珠海格力电器股份有限公司

Dates

Publication Date
20260508
Application Date
20250123

Claims (5)

  1. 1. A diode structure, comprising: A base layer body (100), the base layer body (100) comprising oppositely disposed top and bottom surfaces; a filling groove (200) provided on the base layer body (100), the filling groove (200) extending in a longitudinal direction or a width direction of the base layer body (100), an opening of the filling groove (200) gradually increasing from the bottom surface to the top surface; a filling layer body (300) arranged in the filling groove (200), wherein the filling layer body (300) is provided with a first ohmic contact area in the filling groove (200); A first metal layer body (400) arranged on the top surface of the substrate layer body (100) and forming schottky contact with the substrate layer body (100), wherein at least part of the first metal layer body (400) is embedded in the filling groove (200); The filling groove (200) comprises a first groove body (210) arranged on the basal layer body (100); The second groove body (220) is arranged on the basal layer body (100) and is communicated with the first groove body (210), the second groove body (220) is positioned at one end of the first groove body (210) close to the top surface, the depth of the first groove body (210) is larger than that of the second groove body (220), and the width of the first groove body (210) is smaller than that of the second groove body (220); the filling layer body (300) comprises a P-type epitaxial layer body (310) arranged in the first groove body (210), wherein the P-type epitaxial layer body (310) is attached to the groove wall surface of the first groove body (210); The P-type injection layer body (320) is arranged in the second groove body (220), the P-type injection layer body (320) is connected with the first metal layer body (400), and the doping concentration of the P-type epitaxy in the P-type epitaxy layer body (310) is larger than that of the P-type injection in the P-type injection layer body (320); The diode structure further comprises a second metal layer body (500), wherein a first end of the second metal layer body (500) is arranged in the first groove body (210), a second end of the second metal layer body (500) is arranged in the second groove body (220), and the first end is connected with the P-type epitaxial layer body (310) to form the first ohmic contact region; The P-type injection layer body (320) is provided with a connecting end face (321) attached to the first metal layer body (400), the second metal layer body (500) is provided with a second end face attached to the first metal layer body (400), and the second end face and the connecting end face (321) are located in the same plane.
  2. 2. The diode structure according to claim 1, wherein a protruding layer (410) is disposed on the first metal layer (400), the protruding layer (410) protrudes toward a direction close to the substrate layer (100) with respect to the first metal layer (400), and the protruding layer (410) is embedded in the second groove (220).
  3. 3. The diode structure of claim 2, wherein the thickness of the P-type epitaxial layer (310) is greater than the thickness of the P-type implanted layer (320), and/or, The thickness of the protruding layer (410) is greater than the thickness of the P-type implanted layer (320).
  4. 4. The diode structure of claim 1, the diode structure is characterized by further comprising: And a third metal layer body (600) arranged on the bottom surface of the substrate layer body (100), wherein a second ohmic contact region is arranged between the third metal layer body (600) and the substrate layer body (100).
  5. 5. The diode structure according to claim 1, wherein the number of the filling grooves (200) is at least two, the at least two filling grooves (200) are arranged at intervals along the length direction or the width direction of the substrate layer body (100), and/or, The base layer body (100) comprises an N-type substrate (110) and an N-type epitaxy (120), the N-type epitaxy (120) is arranged on the N-type substrate (110), the filling groove (200) is arranged on the N-type epitaxy (120), and the first metal layer body (400) is attached to the N-type epitaxy (120) to form Schottky contact.

Description

Diode structure Technical Field The invention relates to the technical field of semiconductors, in particular to a diode structure. Background The power diode is a key component of a circuit system and is widely applied to products such as high-frequency inverters, digital products, generators, televisions and the like. The power diode is expanding towards two important directions, namely (1) the power diode is expanding towards tens of millions to tens of amperes, can be applied to occasions such as high-temperature arc wind tunnels and resistance welding machines, and the like, and (2) the reverse recovery time is shorter and shorter, and the power diode is expanding towards the directions of ultrafast, ultrasoft and ultradurable, so that the power diode is not only used for rectifying occasions, but also has different functions in various switching circuits. To meet the application requirements of low power consumption, high frequency, high temperature, miniaturization and the like on-resistance, on-voltage drop, reverse recovery characteristics, high temperature characteristics, and the like are becoming higher and higher. Common rectifying diodes, schottky diodes, PIN diodes are commonly used. Compared with the prior art, the Schottky rectifier has the characteristics of low on-state voltage drop, large leakage current and almost zero reverse recovery time. The PIN fast recovery rectifier has a faster reverse recovery time, but the on-state voltage drop is high. Currently, with the development of microelectronic devices in the directions of low power consumption, high voltage resistance and high reliability, the requirements for semiconductor materials are gradually increasing. Microelectronic devices are increasingly being used in special environments such as high temperature, high irradiation, high frequency, and high power. In order to meet the application of microelectronic devices in the fields of high temperature resistance, irradiation resistance and the like, new semiconductor materials need to be developed so as to improve the performance of the microelectronic devices to the maximum extent. Conventional silicon devices and gallium arsenide devices limit the improvement in device and system performance. The third generation semiconductor materials represented by silicon carbide (SiC) and gallium nitride (GaN) become ideal semiconductor materials for manufacturing high-temperature-resistant, high-power and radiation-resistant electronic devices due to the advantages of the materials such as wide forbidden band width, high critical breakdown electric field and the like. The critical breakdown field strength of SiC materials such as high-temperature and power SiC devices, microwave and high-frequency SiC devices, siC photoelectric devices, irradiation-resistant devices and the like of the SiC-based devices studied at present is 10 times that of Si materials, the forbidden band width and the thermal conductivity of the SiC are 3 times that of the Si materials, and the concentration of intrinsic carriers is only one tenth that of the Si materials. The excellent physical properties enable the semiconductor power device made of the SiC material to have high advantages in high-frequency, high-temperature, high-power, high-irradiation and other environments. SiC can form different crystal structures under different environments, and three crystal structures of 3C-SiC, 4H-SiC and 6H-SiC are commonly used at present. The 4H-SiC material has higher forbidden band width and hole mobility, and lower intrinsic carrier concentration is the main stream material for manufacturing semiconductor devices. However, the structure of the SIC diode device is not optimized for the material characteristics of the SIC, so that the product performance advantage is not obvious compared with that of the Si device in part of parameters, the SIC diode in the process flow adopts the traditional process of the Si diode, and is influenced by the material characteristics of the SIC, the process flow is complex, the production cost is high, and the high-voltage resistance is low. Disclosure of Invention The invention mainly aims to provide a diode structure to solve the problem that a SIC diode device in the prior art is low in high voltage resistance. In order to achieve the above object, according to one aspect of the present invention, there is provided a diode structure including a base layer body including a top surface and a bottom surface disposed opposite to each other, a filling groove disposed on the base layer body, the filling groove extending in a length direction or a width direction of the base layer body, an opening of the filling groove gradually increasing from the bottom surface to the top surface, a filling layer disposed in the filling groove, the filling layer being provided with a first ohmic contact region in the filling groove, and a first metal layer disposed on the top surface of the base layer body and