Trench power field effect transistor device and method

• US 8,648,412 B1
• Filed: 06/04/2012
• Issued: 02/11/2014
• 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:
  US13/487,479
• Time in Patent Office: 617 Days
• Field of Search: 257329-331, 257/333, 257/E29.197, 257/E21.417, 438/270, 438/588
• US Class Current: 257/330
• 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 method of forming a semiconductor device comprising the acts of:

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

forming a trench in the region of semiconductor material extending from the first major surface;

forming an insulator layer adjacent sidewall surfaces of the trench;

forming a control electrode in the trench and overlying a portion of the insulator layer;

forming a body region of a second conductivity type within the region of semiconductor material, wherein the control electrode is configured to control a channel in the body region;

forming a source region within the body region;

forming a body contact structure extending from the major surface;

forming an amorphized body region within the body region and connected to the body contact structure, wherein the act of forming the amorphized body region comprises a first ion implantation;

forming a body contact region of a second conductivity type within the amorphized body region, wherein the act of forming the body contact region comprises a second ion implantation;

annealing the body contact region; and

forming a conductive region within the body contact structure extending from the major surface and contacting the body contact region.

2. The method of claim 1, wherein the act of forming the amorphized body region comprises ion implanting one of germanium, silicon, argon, and xenon.

3. The method of claim 1, wherein the act of forming the amorphized body region comprises ion implanting germanium haying ion energies in a range of 40 KeV to 150 KeV.

4. The method of claim 3, 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.

5. The method of claim 1, wherein the act of forming the body contact region comprises ion implanting boron-11 having ion energies in a range of 200 eV to 20 KeV.

6. The method of claim 5, wherein ion implanting boron-11 comprises on implanting boron-11 at an ion dose in a range of 1×

10¹⁴ atoms/cm³ to 5×

10¹⁵ atoms/cm³.

7. The method of claim 1, wherein the act of forming the body contact region comprises ion implanting boron difluoride having ion energies in a range of 200 eV to 80 KeV.

8. The method of claim 7, 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.

9. The method of claim 1, wherein the act of annealing the body contact region comprises annealing the semiconductor device at a temperature between 900°

C. and 1100°

C. for a period of 2 seconds to 180 seconds.

10. The method of claim 1, further comprising the act of forming a shield electrode in a bottom portion of the trench overlying the insulator layer and wherein the control electrode is overlying the shield electrode.

11. The method of claim 10, wherein the act of forming the shield electrode comprises connecting the shield electrode and the source region.

12. The method of claim 10, wherein forming the control electrode includes connecting the control electrode and the shield electrode.

13. A method of forming a semiconductor device comprising the acts of:

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

forming a trench in the region of semiconductor material extending from the first major surface;

forming an insulator layer adjacent sidewall surfaces of the trench;

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

forming a control electrode in the trench and overlying the shield electrode;

forming a body region of a second conductivity type within the region of semiconductor material, wherein the control electrode is configured to control a channel in the body region;

forming a source region within the body region;

forming a body contact structure extending from the major surface;

forming an amorphized body region within the body region and connected to the body contact structure, wherein the act of forming the amorphized body region comprises a first ion implantation, and wherein the amorphized body region is configured to reduce ion channeling of dopant ions during a subsequent ion implantation;

forming a body contact region of a second conductivity type within the amorphized body region, wherein the act of forming the body contact region comprises the subsequent ion implantation;

annealing the body contact region; and

forming a conductive region within the body contact structure extending from the major surface and contacting the body contact region.

14. The method of claim 13, wherein the act of forming the amorphized body region comprises ion implanting one of germanium, silicon, argon, and xenon.

15. The method of claim 13, wherein the act of forming the amorphized body region comprises ion implanting germanium having ion energies in a range of 40 KeV to 150 KeV and at an ion dose in a range of 1×

10¹³ atoms/cm³ to 1×

10¹⁶ atoms/cm³.

16. The method of claim 13, wherein the act of forming the body contact region comprises ion implanting boron-11 having ion energies in a range of 200 eV to 20 KeV and at an ion dose in a range of 1×

10¹⁴ atoms/cm³ to 5×

10¹⁵ atoms/cm³.

17. The method of claim 13, wherein the act of forming the body contact region comprises ion implanting boron difluoride having ion energies in a range of 200 eV to 80 KeV and at an ion dose in a range of 1×

10¹⁴ atoms/cm³ to 5×

10¹⁵ atoms/cm³.

18. The method of claim 13, wherein the act of annealing the body contact region comprises annealing the semiconductor device at a temperature between 900°

C. and 1100°

C. for a period of 2 seconds to 180 seconds.

19. The method of claim 13, wherein the act of forming the shield electrode comprises connecting the shield electrode and the source region.

20. A method of forming a semiconductor device comprising the acts of:

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

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

forming an insulator layer formed adjacent sidewall surfaces of the first trench;

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

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

forming a body region of a second conductivity type within the region of semiconductor material, wherein the body region of a second conductivity type is laterally spaced from and adjacent to the control electrode;

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

forming second trench extending from the major surface, through the source region and into the body region; and

forming an amorphized body region within the body region, wherein the act of forming the amorphized body region comprises a first ion implantation through the second trench;

forming a body contact region of the second conductivity type within the amorphized body region, wherein the act of forming the body contact region comprises a second ion implantation through the second trench;

annealing the body contact region; and

forming a conductive region within the second trench extending from the major surface and contacting the body contact region.