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CN-119297176-B - Radiation-reinforced IGBT structure and motor driving system

CN119297176BCN 119297176 BCN119297176 BCN 119297176BCN-119297176-B

Abstract

The invention provides a radiation-reinforced IGBT structure and a motor driving system. Compared with the traditional IGBT structure, an N+ buffer layer and an N++ buffer layer which are different in doping concentration and are arranged side by side are introduced between an N-drift region and an FS field stop layer, a polysilicon gate is improved to be a split gate, a central P well region is introduced below the split gate, and P well buffer layers are respectively introduced below a left P well region, a right P well region and the central P well region. The N+ buffer layer and the N++ buffer layer which are introduced can effectively improve the distribution of the back electric field of the IGBT, inhibit avalanche breakdown of a high-low junction formed by the N-drift region and the FS field stop region, and effectively inhibit concentration of an electric field in the gate oxide layer due to existence of the split gate and the central P well, and the P well buffer layer is beneficial to accelerating extraction of holes generated by bombardment of radiation particles in the IGBT body and rapidly flows out of the body. The invention has good inhibition effect on single particle burning and single particle gate penetration.

Inventors

  • ZHOU XINTIAN
  • PENG JUNQI
  • JIA YUNPENG
  • WU YU
  • HU DONGQING
  • TANG YUN
  • ZHAO YUANFU
  • HAN XUEFENG

Assignees

  • 北京工业大学
  • 国网新疆电力有限公司电力科学研究院

Dates

Publication Date
20260512
Application Date
20240830

Claims (6)

  1. 1. A radiation-hardened IGBT structure comprising: A P+ substrate region (1); the FS field stop layer (2) is positioned on the upper surface of the P+ substrate region (1); an N+ buffer layer (11) positioned on the upper surface of the FS field stop layer (2); an N++ buffer layer (12) which is positioned on the upper surface of the FS field stop layer (2) and is parallel to the N+ buffer layer (11); An N-drift region (3) located on the upper surfaces of the N+ buffer layer (11) and the N++ buffer layer (12); the P-well buffer layer is divided into three parts, namely a left P-well buffer layer (13-1), a central P-well buffer layer (13-2) and a right P-well buffer layer (13-3), which are embedded in the N-drift region (3); The P well region is divided into three parts, namely a left P well region (4-1), a right P well region (4-2) and a central P well region (4-3), which are respectively positioned on the upper surfaces of the left P well buffer layer (13-1), the right P well buffer layer (13-3) and the central P well buffer layer (13-2); The P+ region is divided into two parts, namely a left P+ region (5-1) and a right P+ region (5-2), which are respectively embedded into the left P well (4-1) and the right P well (4-2); The N+ source region is divided into two parts, namely a left N+ source region (6-1) and a right N+ source region (6-2), which are respectively embedded into the left P well (4-1) and the right P well (4-2) and are positioned on the side surfaces of the left P+ region (5-1) and the right P+ region (5-2); the gate oxide layer, the polysilicon gate, the isolation oxide layer and the source metal are positioned on the upper surface of the N-drift region (3) and are sequentially arranged from bottom to top; The N+ buffer layer is doped with N-type doping, the doping element is nitrogen or phosphorus, the doping concentration is 1X 10 15 ~5×10 15 cm -3 , the thickness is 1-5 mu m, the N++ buffer layer is doped with N-type doping, the doping element is nitrogen or phosphorus, the doping concentration is 5X 10 15 ~1×10 16 cm -3 , the thickness is 1-5 mu m, the FS field stop layer is doped with N-type doping, the doping element is nitrogen or phosphorus, the doping concentration is 1X 10 16 ~1×10 17 cm -3 , and the thickness is 1-5 mu m; The P well buffer layer is doped with P type, the doping element is aluminum or boron, the doping concentration is 1X 10 16 ~1×10 17 cm -3 , the thickness is 1-5 μm, the doping type of the central P well is doped with P type, the doping element is aluminum or boron, the doping concentration is 1X 10 17 ~9×10 17 cm -3 , and the thickness is 1-45 μm.
  2. 2. A radiation-hardened IGBT structure as claimed in claim 1, characterized in that, The gate oxide layer comprises a left gate oxide layer (7-1) and a right gate oxide layer (7-2), which are both positioned on the upper surface of the N-drift region (3), and the interval area of the left gate oxide layer (7-1) and the right gate oxide layer (7-2) is aligned with the central P well (4-3).
  3. 3. A radiation-hardened IGBT structure as claimed in claim 1, characterized in that, The polysilicon gate comprises a left polysilicon gate (8-1) and a right polysilicon gate (8-2), and the polysilicon gates are respectively positioned on the upper surfaces of the left gate oxide layer (7-1) and the right gate oxide layer (8-2).
  4. 4. A radiation-hardened IGBT structure as claimed in claim 1, characterized in that, The isolation oxide layer comprises a left isolation oxide layer (9-1) and a right isolation oxide layer (9-2), the left isolation oxide layer (9-1) is positioned on the upper surfaces of the left gate oxide layer (7-1) and the left polysilicon gate (8-1), and the right isolation oxide layer (9-2) is positioned on the upper surfaces of the right gate oxide layer (7-2) and the right polysilicon gate (8-2).
  5. 5. A radiation-hardened IGBT structure according to claim 1, wherein the polysilicon gate is N-doped, the doping element is phosphorus, and the doping concentration is 1 x 10 19 ~1×10 20 cm -3 .
  6. 6. A motor drive system comprising a radiation-hardened IGBT structure according to any one of claims 1 to 5.

Description

Radiation-reinforced IGBT structure and motor driving system Technical Field The invention relates to the technical field of semiconductors, in particular to a radiation-reinforced IGBT structure and a motor driving system. Background In aerospace or high-altitude ground application, the IGBT is bombarded by high-energy radiation particles, a single particle effect is easy to occur, namely, the single particle burns SEB and single particle grid-through SEGR, wherein the single particle burns off is that the radiation particles are incident into the IGBT body to generate a large number of electron hole pairs, the holes drift upwards to enter a P-well region under the action of an electric field, the electrons drift downwards to flow out of the IGBT body, a large number of holes flow through a parasitic NPN transistor to enable the NPN transistor to be conducted, an N+ source region injects a large number of electrons into an N-drift region after the NPN-well transistor is conducted, an electric field is transferred from a PN junction formed by a front P-well region and the N-drift region to a high-low junction formed by a back N-drift region and an FS field stop layer, when the electric field of the back high-low junction reaches a critical breakdown electric field, avalanche breakdown occurs, a large number of electron hole pairs are further generated, the holes drift upwards to maintain the conduction of the parasitic NPN-well region, the NPN transistor is formed, finally, the single particle grid-through is burnt off due to overhigh current, the radiation particles enter the IGBT body to form a large number of electron hole pairs, the electron hole pairs are formed, the PN junction is formed in the N-junction, the N-gate field has a high oxidation layer, and the oxidation layer is broken down, and the oxidation layer is caused, and the oxidation layer is broken down, and the oxidation layer is increased. The radiation failure of the IGBT is a main difficulty facing the application of the IGBT on the ground at a space and a high altitude. Disclosure of Invention In order to solve the problems of the conventional IGBT, the invention provides a radiation-reinforced IGBT structure and a motor driving system. The technical problems to be solved by the invention are realized by the following technical scheme: one embodiment of the present invention provides a radiation-hardened IGBT structure comprising: A P+ substrate region 1; The FS field stop layer 2 is positioned on the upper surface of the P+ substrate region 1; An N+ buffer layer 11 located on the upper surface of the FS field stop layer 2; An N++ buffer layer 12, which is positioned on the upper surface of the FS field stop layer 2 and is parallel to the N+ buffer layer 11; an N-drift region 3 located on the upper surfaces of the N+ buffer layer 11 and the N++ buffer layer 12; the P well buffer layer is divided into three parts, namely a left P well buffer layer 13-1, a central P well buffer layer 13-2 and a right P well buffer layer 13-3, which are embedded in the N-drift region 3; the P well region is divided into three parts, namely a left P well region 4-1, a right P well region 4-2 and a central P well region 4-3, which are respectively positioned on the upper surfaces of the left P well buffer layer 13-1, the right P well buffer layer 13-3 and the central P well buffer layer 13-2; The P+ region is divided into two parts, namely a left P+ region 5-1 and a right P+ region 5-2, which are respectively embedded in the left P well 4-1 and the right P well 4-2; The N+ source region is divided into two parts, namely a left N+ source region 6-1 and a right N+ source region 6-2, which are respectively embedded in the left P well 4-1 and the right P well 4-2 and are positioned on the side surfaces of the left P+ region 5-1 and the right P+ region 5-2; the gate oxide layer, the polysilicon gate, the isolation oxide layer and the source metal are positioned on the upper surface of the N-drift region 3 and are sequentially arranged from bottom to top. Further, the gate oxide layer includes a left gate oxide layer 7-1 and a right gate oxide layer 7-2, which are both located on the upper surface of the N-drift region 3, and the spaced areas of the left gate oxide layer 7-1 and the right gate oxide layer 7-2 are aligned with the central P-well 4-3. Further, the polysilicon gates comprise a left polysilicon gate 8-1 and a right polysilicon gate 8-2, and are respectively positioned on the upper surfaces of the left gate oxide layer 7-1 and the right gate oxide layer 8-2. Further, the isolation oxide layer comprises a left isolation oxide layer 9-1 and a right isolation oxide layer 9-2, the left isolation oxide layer 9-1 is positioned on the upper surfaces of the left gate oxide layer 7-1 and the left polysilicon gate 8-1, and the right isolation oxide layer 9-2 is positioned on the upper surfaces of the right gate oxide layer 7-2 and the right polysilicon gate 8-2 P