Search

CN-224218742-U - Shielding gate groove type MOSFET terminal structure

CN224218742UCN 224218742 UCN224218742 UCN 224218742UCN-224218742-U

Abstract

The application provides a shielded gate trench type MOSFET terminal structure, and relates to the technical field of semiconductors. The shielding gate groove type MOSFET terminal structure comprises a substrate, a plurality of active area grooves, at least one terminal voltage division ring groove and at least one terminal stop ring groove, wherein the plurality of active area grooves, the at least one terminal voltage division ring groove and the at least one terminal stop ring groove are arranged on the surface of the substrate, the terminal voltage division ring groove is arranged on the outer side of the active area groove and surrounds the active area groove, the terminal stop ring groove is arranged on the outer side of the terminal voltage division ring groove, the at least one terminal voltage division ring groove comprises a target terminal voltage division ring groove nearest to the active area groove, and the distance between the target terminal voltage division ring groove and the active area groove is equal to the distance between two adjacent active area grooves. The shielded gate trench type MOSFET terminal structure provided by the application has the advantages of stabilizing the withstand voltage of the device and reducing the electric leakage of the device in the withstand voltage process.

Inventors

  • MO JIANING
  • XU LEIJUN

Assignees

  • 捷捷微电(南通)科技有限公司

Dates

Publication Date
20260508
Application Date
20250519

Claims (10)

  1. 1. A shielded gate trench MOSFET termination structure, the shielded gate trench MOSFET termination structure comprising: A substrate; The substrate comprises a plurality of active region grooves, at least one terminal pressure dividing ring groove and at least one terminal stop ring groove, wherein the terminal pressure dividing ring groove is positioned at the outer side of the active region groove and surrounds the active region groove, the terminal stop ring groove is positioned at the outer side of the terminal pressure dividing ring groove, The at least one terminal voltage division ring groove comprises a target terminal voltage division ring groove closest to the active region groove, and the distance between the target terminal voltage division ring groove and the active region groove is equal to the distance between two adjacent active region grooves.
  2. 2. The shielded gate trench MOSFET termination structure of claim 1 wherein said target termination voltage divider ring trench comprises a first lateral trench and a first longitudinal trench integrally connected, said first longitudinal trench being disposed parallel to said active area trench, said first lateral trench being disposed perpendicular to said active area trench, and any point at an end of each of said active area trenches being equidistant from a shortest distance of said first lateral trench.
  3. 3. The shielded gate trench MOSFET termination structure of claim 2 wherein the ends of each of said active area trenches are each configured as a first arc, said first lateral trench is configured as a plurality of sequentially connected second arcs, each of said second arcs is configured outside one of said first arcs, and each of said second arcs is located at the same point as a center of a circle corresponding to one of said first arcs.
  4. 4. The shielded gate trench MOSFET termination structure of claim 1, wherein at least two of said termination voltage dividing ring trenches are disposed in parallel when the number of said termination voltage dividing ring trenches is at least two.
  5. 5. The shielded gate trench MOSFET termination structure of claim 1, wherein when the number of termination voltage division ring trenches is at least two, a pitch between two adjacent termination voltage division ring trenches is equal to a pitch between two adjacent active area trenches.
  6. 6. The shielded gate trench MOSFET terminal structure of claim 1 wherein the terminal voltage divider ring trench includes a first lateral trench and a first longitudinal trench integrally connected, the terminal stop ring trench includes a second lateral trench and a second longitudinal trench integrally connected, a junction of the first lateral trench and the first longitudinal trench is configured as an arc, a junction of the second lateral trench and the second longitudinal trench is also configured as an arc, and an arc of a junction of the first lateral trench and the first longitudinal trench, and an arc of a junction of the second lateral trench and the second longitudinal trench are equal.
  7. 7. The shielded gate trench MOSFET termination structure of claim 1, wherein a gate contact hole is provided in each of said active area trenches, and gate contacts Kong Liancheng in a plurality of active area trenches are aligned, said gate contact holes being in metal contact with the gate.
  8. 8. The shielded gate trench MOSFET termination structure of claim 1, wherein first source contact holes are disposed in the active area trenches, second source contact holes are disposed between the target termination voltage dividing ring trench and the active area trenches, and between the target termination voltage dividing ring trench and two adjacent active area trenches, third source contact holes are disposed in the termination voltage dividing ring trench, and the first source contact holes, the second source contact holes, and the third source contact holes are all connected with source metal.
  9. 9. The shielded gate trench MOSFET termination structure of claim 8, wherein a portion of said second source contact hole is aligned with said first source contact Kong Liancheng and another portion of said second source contact hole is aligned with said third source contact Kong Liancheng.
  10. 10. The shielded gate trench MOSFET termination structure of claim 1, wherein a first drain contact hole is provided in the termination cut-off ring trench, a second drain contact hole is provided in the substrate proximate the termination cut-off ring trench, and the first drain contact hole and the second drain contact hole are both in metal contact with the drain.

Description

Shielding gate groove type MOSFET terminal structure Technical Field The application relates to the technical field of semiconductors, in particular to a shielding gate trench type MOSFET terminal structure. Background The switching tube formed by the semiconductor power device is the core of the modern power converter, and the commonly used power device is formed by processing metal, oxide and semiconductor materials. The conventional shielded gate trench type power metal oxide semiconductor transistor controls the switching of the device by controlling the externally applied bias of the gate polysilicon, and when the gate is externally applied with forward bias, a conductive channel of an inversion layer is formed on the surfaces of the oxide and the semiconductor by a gate electric field, so that the device is conducted. On the contrary, the grid electrode is connected with zero potential or negative potential, and the device is in an off state. A Metal-Oxide-Semiconductor Field-Effect Transistor (Metal-Oxide-semiconductor field effect transistor) is formed by introducing a vertical polysilicon field plate into a body, changing the triangular electric field distribution when the direction is voltage-resistant into a rectangular electric field distribution, and increasing the avalanche breakdown voltage. The two-dimensional charge depletion effect is utilized, the P-type body region and the drift region are mutually depleted, and the shielding gate structure and the drift region are mutually depleted, so that the doping concentration of the drift region is increased, the on-resistance is reduced, and the withstand voltage of the device can be ensured to meet the requirement. Meanwhile, as the shielding grid is positioned between the control grid and the drain electrode, a part of feedback capacitance is shielded, and therefore the shielding grid MOSFET has less switch damage. The shielding gate MOSFET is a two-dimensional charge depletion device, the charge depletion state of the terminal structure determines the stability of avalanche breakdown voltage and repeated avalanche resistance of the shielding gate MOSFET device, and when the charge of a terminal area of a conventional structure cannot be perfectly depleted, the terminal of the device is easy to be unstable in withstand voltage, and the terminal area is easy to be a weak point. In addition, the terminal area is more complex than two-dimensional depletion due to charge depletion in multiple directions, the process window is smaller, the leakage of the device in the voltage-resistant process is large due to process fluctuation, and the application requirement cannot be met. In summary, the problem of unstable withstand voltage and large leakage current of the shielded gate MOSFET device exists in the prior art. Disclosure of utility model The application aims to provide a shielded gate trench type MOSFET terminal structure, which solves the problems of unstable withstand voltage and large leakage of a shielded gate MOSFET device in the prior art. In order to achieve the above object, the technical scheme adopted by the embodiment of the application is as follows: The embodiment of the application provides a shielding gate trench type MOSFET terminal structure, which comprises: A substrate; The substrate comprises a plurality of active region grooves, at least one terminal pressure dividing ring groove and at least one terminal stop ring groove, wherein the terminal pressure dividing ring groove is positioned at the outer side of the active region groove and surrounds the active region groove, the terminal stop ring groove is positioned at the outer side of the terminal pressure dividing ring groove, The at least one terminal voltage division ring groove comprises a target terminal voltage division ring groove closest to the active region groove, and the distance between the target terminal voltage division ring groove and the active region groove is equal to the distance between two adjacent active region grooves. Optionally, the target terminal voltage division ring groove comprises a first transverse groove and a first longitudinal groove which are integrally connected, the first longitudinal groove is parallel to the active region groove, the first transverse groove is perpendicular to the active region groove, and any point of the end part of each active region groove is equal to the shortest distance between the first transverse groove. Optionally, each end of the active area groove is set to be a first arc, the first transverse groove is set to be a plurality of sections of second arcs which are sequentially connected, each section of second arc is set to be outside one first arc, and each section of second arc is located at the same point with the circle center corresponding to one first arc. Optionally, when the number of the terminal pressure dividing ring grooves is at least two, the at least two terminal pressure dividing ring grooves a