Semiconductor component

• US 8,035,161 B2
• Filed: 06/01/2010
• Issued: 10/11/2011
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Casteel, Carroll, Venkatraman, Prasad, Grivna, Gordon M., Robb, Francine Y., Chang, George
• Primary Examiner(s): Blum; David S
• Application Number:
  US12/790,987
• Publication Number:
  US 20100237409A1
• Time in Patent Office: 497 Days
• Field of Search: 257/331, 257/510, 257/E29.257
• US Class Current: 257/331
• CPC Class Codes: H01L 29/0696 of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/4236 within a trench, e.g. trench gate electrode, groove gate electrode
• CPC Class Codes: H01L 29/42376 characterised by the length or the sectional shape
• CPC Class Codes: H01L 29/4238 characterised by the surface lay-out
• CPC Class Codes: H01L 29/66727 with a step of recessing the source electrode
• CPC Class Codes: H01L 29/66734 with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• CPC Class Codes: H01L 29/7811 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236

Abstract

A semiconductor component resistant to the formation of a parasitic bipolar transistor and a method for manufacturing the semiconductor component using a reduced number of masking steps. A semiconductor material of N-type conductivity having a region of P-type conductivity is provided. A doped region of N-type conductivity is formed in the region of P-type conductivity. Trenches are formed in a semiconductor material and extend through the regions of N-type and P-type conductivities. A field oxide is formed from the semiconductor material such that portions of the trenches extend under the field oxide. The field oxide serves as an implant mask in the formation of source regions. Body contact regions are formed from the semiconductor material and an electrical conductor is formed in contact with the source and body regions. An electrical conductor is formed in contact with the backside of the semiconductor material.

Claims

1. A power semiconductor component, comprising:

a semiconductor material having first and second major surfaces, an active area, and a peripheral area;

a layer of impurity material of a first conductivity type extending from the first major surface into the semiconductor material a first distance;

a first trench extending from the first major surface into the semiconductor material and from the active area to the peripheral area;

a field oxide in the peripheral area, the field oxide over a portion of the first trench that extends to the peripheral area;

a layer of polysilicon disposed over a portion of the field oxide; and

semiconductor material disposed in the first trench.

2. The power semiconductor component of claim 1, further including an opening in a portion of the semiconductor material between the first trench and the peripheral area, the opening having a sidewall, a floor, and extending from the first major surface into the semiconductor material a second distance, the second distance greater than the first distance.

3. The power semiconductor component of claim 2, further including a doped region extending from the floor of the opening into the semiconductor material.

4. The power semiconductor component of claim 3, further including:

a first conductor in contact with the doped region and the sidewall of the opening; and

a second conductor in contact with the second major surface.

5. The power semiconductor component of claim 1, further including:

a second trench extending from the first major surface into the semiconductor material and from the active area to the peripheral area;

semiconductor material disposed in the second trench;

an opening in a portion of the semiconductor material between the first trench and the second trench, the opening having a sidewall, a floor, and extending from the first major surface into the semiconductor material a second distance, the second distance greater than the first distance; and

a doped region extending from the floor of the opening into the semiconductor material.

6. A semiconductor component, comprising:

a semiconductor material having first and second major surfaces, the semiconductor material comprising an epitaxial layer disposed on a semiconductor substrate and having an active area and a peripheral area;

a plurality of trench structures in the semiconductor material, wherein the plurality of trench structures extend vertically from the first major surface into the epitaxial layer and laterally from the active area to the peripheral area; and

a field oxide formed from the peripheral area, wherein a portion of the plurality of trenches extends under the field oxide.

7. The semiconductor component of claim 6, further including:

a layer of impurity material of a first conductivity type extending from the first major surface into the semiconductor material a first distance;

a layer of polysilicon over the active and the peripheral areas and patterned to have a first portion over a first portion of the field oxide and a second portion over at least one of the plurality of trench structures;

a layer of dielectric material having a first portion over the first portion of the layer of polysilicon and a second portion over the second portion of the layer of polysilicon; and

a trench in the layer of semiconductor material, the trench having a floor and a sidewall and extending from the major surface into the semiconductor material a second distance.

8. The semiconductor component of claim 7, further including a doped region of a second conductivity type extending from the floor of the trench into the semiconductor material.

9. The semiconductor component of claim 8, further including a first conductor in contact with the second doped region and the sidewall of the trench and a second conductor in contact with the second major surface.

10. The semiconductor component of claim 6, wherein the semiconductor material comprises a layer of impurity material of a first conductivity type extending from the first major surface into the semiconductor material a first distance, and further including:

a layer of polysilicon over the active and the peripheral areas having a first portion over a first portion of the field oxide layer and a second portion in a first trench of the plurality of trenches, and a third portion of the layer of polysilicon in a third trench of the plurality of trenches;

a layer of dielectric material over at least the first, second, and third portions of the layer of polysilicon; and

a trench in the layer of semiconductor material between the first and second trenches, the trench having a floor, first and second sidewalls, and extending from the major surface of the exposed portion of the layer of impurity material into the semiconductor material a second distance, wherein the floor exposes a second portion of the semiconductor material and wherein the second distance is greater than the first distance and the first and second sidewalls expose a portion of the layer of impurity material of the first conductivity type.

11. The method of claim 10, further including a doped region of a second conductivity type in the second portion of the semiconductor material.

12. A semiconductor component, comprising:

a semiconductor material having a major surface;

one or more trenches that extend from the major surface into the semiconductor material; and

a field oxide over a peripheral region of the semiconductor material, wherein the one or more trenches extends under the field oxide.

13. The semiconductor component of claim 12, wherein the semiconductor material comprises:

a substrate; and

an epitaxial layer formed on the substrate.

14. The semiconductor component of claim 12, further including a first portion of a polysilicon layer in the one or more trenches and a second portion of the polysilicon over a portion of the field oxide.

15. The semiconductor component of claim 14, further including a first doped region of a first conductivity type in a first portion of the semiconductor material and a second doped region of a second conductivity type in a second portion of the semiconductor material.

16. The semiconductor component of claim 15, further including a layer of dielectric material over the first portion of the polysilicon layer and over the second portion of the polysilicon layer, wherein the layer of dielectric material is absent from the region that is between the field oxide and a first trench of the one or more trenches.

17. The semiconductor component of claim 16, wherein the field oxide is absent from a region that is adjacent the first trench.

18. The semiconductor component of claim 14, further including:

a first doped region of a first conductivity type in the semiconductor material, wherein the one or more trenches extend further from the major surface into the semiconductor material than the first doped region; and

a second doped region of a second conductivity type in a second portion of the semiconductor material.

19. The semiconductor component of claim 14, further including a first metal contact in contact with the first and second doped regions and a second metal contact in contact with the second surface of the semiconductor material.