Trench power field effect transistor device and method

• US 9,368,615 B2
• Filed: 02/10/2014
• Issued: 06/14/2016
• Est. Priority Date: 06/04/2012
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Burke, Peter A, Suwhanov, Agajan, Venkatraman, Prasad
• Primary Examiner(s): Doan, Theresa T.
• Application Number:
  US14/177,140
• Publication Number:
  US 20140151788A1
• Time in Patent Office: 855 Days
• Field of Search: 257329-330, 438/270, 438/588
• US Class Current: 1/1
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• 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 29/41766 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 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/4933 with a silicide layer contacting the silicon layer, e.g. Polycide gate with a barrier layer between the silicide and silicon layers H01L29/4941
• 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 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236

Abstract

In one embodiment, a structure for a trench power field effect transistor device with controlled, shallow, abrupt, body contact regions.

Claims

1. A semiconductor device comprising:

a region of semiconductor material of a first conductivity type having a major surface;

a trench extending into the region of semiconductor material from the major surface;

an insulator layer formed adjacent sidewall surfaces of the trench;

a shield electrode in a bottom portion of the trench and overlying a portion of the insulator layer;

a gate electrode in the trench and overlying the shield electrode;

a body region of a second conductivity type formed within the region of semiconductor material and adjacent to the gate electrode;

a source region of the first conductivity type within the body region;

an amorphized region of the second conductivity type within the body region, wherein the amorphized region is formed as a result of a first ion implantation, wherein the first ion implantation comprises a germanium ion implantation; and

a body contact region of the second conductivity type within the amorphized region, wherein the body contact region of the second conductivity type is formed as a result of a second ion implantation, wherein the second ion implantation comprises a boron ion implantation.

2. The semiconductor device of claim 1, wherein the germanium ion implantation comprises ion implanting germanium having ion energies in a range of 40 KeV to 150 KeV.

3. The semiconductor device of claim 2, wherein ion implanting germanium comprises ion implanting germanium at an ion dose in a range of 1×

10¹³ atoms/cm³ to 1×

10¹⁶ atoms/cm³.

4. The semiconductor device of claim 1, wherein the boron ion implantation comprises ion implanting boron-11 having ion energies in a range of 200 eV to 20 KeV.

5. The semiconductor device of claim 4, wherein ion implanting boron-11 comprises ion implanting boron-11 at an ion dose in a range of 1×

10¹⁴ atoms/cm³ to 5×

10¹⁵ atoms/cm³.

6. The semiconductor device of claim 1, wherein the boron ion implantation comprises ion implanting boron difluoride having ion energies in a range of 200 eV to 80 KeV.

7. The semiconductor device of claim 6, wherein ion implanting boron difluoride comprises ion implanting boron difluoride at an ion dose in a range of 1×

10¹⁴ atoms/cm³ to 5×

10¹⁵ atoms/cm³.

8. A semiconductor device comprising:

a region of semiconductor material of a first conductivity type having a major surface;

a trench extending into the region of semiconductor material from the major surface;

an insulator layer formed adjacent sidewall surfaces of the trench;

a shield electrode in a bottom portion of the trench and overlying a portion of the insulator layer;

a gate electrode in the trench and overlying the shield electrode;

a body region of a second conductivity type formed within the region of semiconductor material and adjacent to the gate electrode;

a source region of the first conductivity type within the body region;

an amorphized region of the second conductivity type within the body region, wherein the amorphized region is formed as a result of a first ion implantation, wherein the first ion implantation comprises a silicon ion implantation; and

a body contact region of the second conductivity type within the amorphized region, wherein the body contact region of the second conductivity type is formed as a result of a second ion implantation, wherein the second ion implantation comprises a boron ion implantation.

9. semiconductor device comprising:

a region of semiconductor material of a first conductivity type having a major surface;

a trench extending into the region of semiconductor material from the major surface;

an insulator layer formed adjacent sidewall surfaces of the trench;

a shield electrode in a bottom portion of the trench and overlying a portion of the insulator layer;

a gate electrode in the trench and overlying the shield electrode;

a body region of a second conductivity type formed within the region of semiconductor material and adjacent to the gate electrode;

a source region of the first conductivity type within the body region;

an amorphized region of the second conductivity type within the body region, wherein the amorphized region is formed as a result of a first ion implantation, wherein the first ion implantation comprises an xenon ion implantation; and

a body contact region of the second conductivity type within the amorphized region, wherein the body contact region of the second conductivity type is formed as a result of a second ion implantation, wherein the second ion implantation comprises a boron ion implantation.