Trench power semiconductor and method of making the same

• US 10,516,027 B2
• Filed: 05/28/2018
• Issued: 12/24/2019
• Est. Priority Date: 06/30/2017
• Status: Active Grant

• Current Assignee: Super Group Semiconductor Co., Ltd.
• Original Assignee: Super Group Semiconductor Co., Ltd.
• Inventors: Hsu, Hsiu-Wen, Yeh, Chun-Ying, Lee, Yuan-Ming
• Primary Examiner(s): Mulpuri, Savitri
• Application Number:
  US15/990,719
• Publication Number:
  US 20190006479A1
• Time in Patent Office: 575 Days
• CPC Class Codes: H01L 21/76898 formed through a semiconductor substrate
• CPC Class Codes: H01L 21/823437 with a particular manufacturing method of the gate conductors, e.g. particular materials, shapes
• CPC Class Codes: H01L 29/0649 Dielectric regions, e.g. SiO2 regions, air gaps
• CPC Class Codes: H01L 29/0847 of field-effect transistors with insulated gate H01L29/0653 takes precedence; with a passive supplementary region between source or drain and substrate related to punch-through, capacity or isolation phenomena H01L29/1079; with LDD or DDD structure H01L29/7833; for thin film transistors H01L29/78618
• CPC Class Codes: H01L 29/1095 Body region, i.e. base region, of DMOS transistors or IGBTs cell layout H01L29/0696
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• 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 29/66734 with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236

Abstract

The present disclosure provides a trench power semiconductor component and a method of making the same. The trench power semiconductor component includes a substrate, an epitaxial layer, and a trench gate structure. The epitaxial layer is disposed on the substrate, the epitaxial layer having at least one trench formed therein. The trench gate structure is located in the at least one trench. The trench gate structure includes a bottom insulating layer covering a lower inner wall of the at least one trench, a shielding electrode located in the lower half part of the at least one trench, a gate electrode disposed on the shielding electrode, an inter-electrode dielectric layer disposed between the gate electrode and the shielding electrode, an upper insulating layer covering an upper inner wall of the at least one trench, and a protection structure including a first wall portion and a second side wall portion.

Claims

1. A trench power semiconductor component, comprising:

a substrate;

an epitaxial layer disposed on the substrate, the epitaxial layer having at least one trench formed therein; and

a trench gate structure located in the at least one trench, wherein the trench gate structure includes;

a bottom insulating layer covering a lower inner wall of the at least one trench;

a shielding electrode located in the lower half part of the at least one trench, the shielding electrode and the epitaxial layer being separated from each other by the bottom insulating layer;

a gate electrode disposed on the shielding electrode;

an inter-electrode dielectric layer disposed between the gate electrode and the shielding electrode;

an upper insulating layer covering an upper inner wall of the at least one trench, wherein the upper insulating layer, the bottom insulating layer, and the inter-electrode dielectric layer jointly define a first slit and a second slit, one located on either side of the inter-electrode dielectric layer; and

a protection structure including a first wall portion and a second wall portion, wherein the first wall portion fills at least one portion of the first slit and the second wall portion fills at least one portion of the second slit, wherein the first wall portion extends from an opening end of the trench into the first slit, and the second wall portion extends from the opening end of the trench into second slit

wherein a bottom tip of the first wall portion and a bottom tip of the second wall portion are higher than or at the same level as a top end of the shielding electrode.

2. The trench power semiconductor component according to claim 1, wherein the gate electrode includes a first extension portion and a second extension portion respectively located in the first slit and the second slit.

3. The trench power semiconductor component according to claim 1, wherein the first wall portion and the second wall portion are separated from the gate electrode by the inter-electrode dielectric layer and the upper insulating layer.

4. The trench power semiconductor component according to claim 1, further comprising a base region and a source region disposed above the base region, wherein an edge of the base region and an edge of the source region are inclined downward.

8. The trench power semiconductor component according to claim 1, wherein sectional outlines of the first wall portion and the second wall portion are both hooked shaped.

5. A trench power semiconductor component, comprising:

a substrate;

an epitaxial layer disposed on the substrate, the epitaxial layer having at least one trench formed therein; and

a trench gate structure located in the at least one trench, wherein the trench gate structure includes;

a bottom insulating layer covering a lower inner wall of the at least one trench;

a shielding electrode located in the lower half part of the at least one trench, the shielding electrode and the epitaxial layer being separated from each other by the bottom insulating layer;

a gate electrode disposed on the shielding electrode;

an inter-electrode dielectric layer disposed between the gate electrode and the shielding electrode;

an upper insulating layer covering an upper inner wall of the at least one trench, wherein the upper insulating layer, the bottom insulating layer, and the inter-electrode dielectric layer jointly define a first slit and a second slit, one located on either side of the inter-electrode dielectric layer; and

a protection structure including a first wall portion and a second wall portion, wherein the first wall portion fills at least one portion of the first slit and the second wall portion fills at least one portion of the second slit,

wherein the first wall portion of the trench extends from an opening end of the trench into the first slit, and the second side wall portion of the trench extends from the opening end of the trench into the second slit.

6. A trench power semiconductor component, comprising:

a substrate;

an epitaxial layer disposed on the substrate, the epitaxial layer having at least one trench formed therein; and

a trench gate structure located in the at least one trench, wherein the trench gate structure includes;

a bottom insulating layer covering a lower inner wall of the at least one trench;

a shielding electrode located in the lower half part of the at least one trench, the shielding electrode and the epitaxial layer being separated from each other by the bottom insulating layer;

a gate electrode disposed on the shielding electrode;

an inter-electrode dielectric layer disposed between the gate electrode and the shielding electrode;

an upper insulating layer covering an upper inner wall of the at least one trench, wherein the upper insulating layer, the bottom insulating layer, and the inter-electrode dielectric layer jointly define a first slit and a second slit, one located on either side of the inter-electrode dielectric layer; and

a protection structure including a first wall portion and a second wall portion, wherein the first wall portion fills at least one portion of the first slit and the second wall portion fills at least one portion of the second slit,

wherein the gate electrode includes a first extension portion and a second extension portion respectively located in the first slit and the second slit.

7. The trench power semiconductor component according to claim 6, wherein the first wall portion and the second wall portion respectively have two bottom portions that are bent toward each other.