FIELD EFFECT TRANSISTOR CONTAINING A WIDE BAND GAP SEMICONDUCTOR MATERIAL IN A DRAIN

• US 20090121258A1
• Filed: 11/13/2007
• Published: 05/14/2009
• Est. Priority Date: 11/13/2007
• Status: Active Grant

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Kumar, Arvind
• Granted Patent: US 7,936,042 B2
• Time in Patent Office: Days
• US Class Current: 257/192
• CPC Class Codes: H01L 21/26586 characterised by the angle between the ion beam and the crystal planes or the main crystal surface
• CPC Class Codes: H01L 29/1045 the doping structure being parallel to the channel length, e.g. DMOS like
• CPC Class Codes: H01L 29/165 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/6653 using the removal of at least part of spacer, e.g. disposable spacer
• CPC Class Codes: H01L 29/66636 with source or drain recessed by etching or first recessed by etching and then refilled
• CPC Class Codes: H01L 29/66659 with asymmetry in the channel direction, e.g. lateral high-voltage MISFETs with drain offset region, extended drain MISFETs
• CPC Class Codes: H01L 29/7833 with lightly doped drain or source extension, e.g. LDD MOSFET's; DDD MOSFET's for thin film transistors H01L29/78618
• CPC Class Codes: H01L 29/7835 with asymmetrical source and drain regions, e.g. lateral high-voltage MISFETs with drain offset region, extended drain MISFETs
• CPC Class Codes: H01L 29/7848 the means being located in the source/drain region, e.g. SiGe source and drain

Abstract

A field effect transistor comprising a silicon containing body is provided. After formation of a gate dielectric, gate electrode, and a first gate spacer, a drain side trench is formed and filled with a wide band gap semiconductor material. Optionally, a source side trench may be formed and filled with a silicon germanium alloy to enhance an on-current of the field effect transistor. Halo implantation and source and drain ion implantation are performed to form various doped regions. Since the wide band gap semiconductor material as a wider band gap than that of silicon, impact ionization is reduced due to the use of the wide band gap semiconductor material in the drain, and consequently, a breakdown voltage of the field effect transistor is increased compared to transistors employing silicon in the drain region.

Claims

1. A field effect transistor comprising:

a body having a doping of a first conductivity type and including a silicon containing body portion comprising silicon, and a wide band gap semiconductor material containing body portion comprising a wide band gap semiconductor material, and a silicon germanium alloy containing body portion comprising a silicon germanium alloy having a different composition than said silicon containing body portion, wherein said silicon containing body portion abuts said silicon germanium alloy containing body portion; and

a drain region including a wide band gap semiconductor material containing drain portion abutting said wide band gap semiconductor material containing body portion, wherein said wide band gap semiconductor material containing body portion and said wide band gap semiconductor material containing drain portion comprises a semiconductor material having a wider band gap than silicon.

2. The field effect transistor of claim 1, further comprising a gate dielectric vertically abutting said body.

3. The field effect transistor of claim 2, wherein said drain region further contains a silicon containing drain portion abutting said gate dielectric.

4. The field effect transistor of claim 2, wherein said wide band gap semiconductor material containing body portion abuts said gate dielectric.

5. The field effect transistor of claim 2, wherein said body further includes a drain side halo region that abuts said wide band gap semiconductor material containing body portion and said gate dielectric.

6. The field effect transistor of claim 2, further comprising a source region including said silicon-germanium alloy containing source portion and abutting said body

8. The field effect transistor of claim 6, wherein said source region further comprises a silicon containing source portion abutting said gate dielectric.

9. The field effect transistor of claim 6, wherein said body further includes a source side halo region that abuts said silicon-germanium alloy containing source portion.

10. The field effect transistor of claim 1, further comprising:

a buried insulator layer vertically abutting said body; and

a handle substrate vertically abutting said buried insulator layer.

11. The field effect transistor of claim 1, wherein said wide band gap semiconductor material containing body portion and said wide band gap semiconductor material containing drain portion comprise stoichiometric silicon carbide in which an atomic ratio between silicon and carbon is substantially 1.

12. The field effect transistor of claim 1, wherein said wide band gap semiconductor material containing body portion and said wide band gap semiconductor material containing drain portion comprise one of gallium nitride, aluminum nitride, boron nitride, and diamond.

21. The field effect transistor of claim 1, further comprising a silicon-germanium alloy containing source portion having a silicon germanium alloy and having a doping of a second conductivity type and abutting said silicon germanium alloy containing body portion, wherein said second conductivity type is the opposite of the first conductivity type.

22. The field effect transistor of claim 21, further comprising a gate spacer that abut said silicon-germanium alloy containing source portion.

7. (canceled)

13-20. -20. (canceled)