Oxide-bypassed lateral high voltage structures and methods

• US 7,473,966 B1
• Filed: 11/09/2005
• Issued: 01/06/2009
• Est. Priority Date: 11/09/2004
• Status: Active Grant

• Current Assignee: MaxPower Semiconductor, Inc. (Vishay Intertechnology Incorporated)
• Original Assignee: Richard A. Blanchard
• Inventors: Blanchard, Richard A.
• Primary Examiner(s): Smith; Zandra
• Assistant Examiner(s): Green; Telly D
• Application Number:
  US11/272,477
• Time in Patent Office: 1,154 Days
• Field of Search: 257/213, 257/513, 257/335, 257/401, 257339-343, 257/E29.256
• US Class Current: 257/342
• CPC Class Codes: H01L 29/0696 of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs
• CPC Class Codes: H01L 29/0873 Drain regions
• CPC Class Codes: H01L 29/0878 Impurity concentration or distribution
• CPC Class Codes: H01L 29/1083 with an inactive supplementary region, e.g. for preventing punch-through, improving capacity effect or leakage current
• 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 29/7816 Lateral DMOS transistors, i.e. LDMOS transistors
• CPC Class Codes: H01L 29/7824 with a substrate comprising an insulating layer, e.g. SOI-LDMOS transistors
• CPC Class Codes: H01L 29/8611 Planar PN junction diodes

Abstract

A lateral high-voltage active device structure, in which field-shaping trench electrodes are capacitively coupled to the voltage-withstand region near the source end thereof.

Claims

1. A lateral semiconductor device, comprising:

a carrier-emission structure;

a voltage-withstand structure, through which carriers are emitted by said carrier-emission structure can pass laterally; and

trench electrodes which are capacitively coupled to sidewalls of said voltage-withstand structure to provide electric field shaping therein, wherein the voltage-withstand structure exhibits a lateral taper adjacent to a tapered drift region, said drift region narrower near a drain compared to wider nearer a source.

4. The device of claim 1, wherein said carrier-emission structure includes a source diffusion, and said trench electrodes are electrically connected to said source region.

5. The device of claim 1, wherein said carrier-emission structure includes an anode and a semiconductor diffusion abutting said anode.

6. The device of claim 1, wherein said carrier-emission structure includes a source diffusion, a semiconductor channel which abuts said source diffusion, and a gate which is capacitively coupled to said channel.

7. The device of claim 1, wherein said carrier-emission structure includes an emitter diffusion, and a base diffusion which has a conductivity type opposite to that of said emitter diffusion and said voltage-withstand region.

8. The device of claim 1, further comprising an electrical contact which receives carriers emitted by said carrier-emission structure, after said carriers have passed through said voltage-withstand region.

2. A lateral semiconductor device, comprising:

a carrier-emission structure, which can emit charge carriers of a first type;

a voltage-withstand structure, through which carriers emitted by said carrier-emission structure can pass laterally, adjacent to a laterally tapered dielectric structure;

a carrier-collection structure, which receives charge carriers of said first type which have passed through said voltage-withstand structure; and

trench electrodes which adjoin opposite sides of said voltage-withstand structure, and which have tapered sidewalls adjoining the tapered dielectric structure, said trench electrodes capacitively coupled to provide electric field shaping in said voltage-withstand structure.

9. The device of claim 2, wherein said carrier-emission structure includes a source diffusion, a semiconductor channel which abuts said source diffusion, and a gate which is capacitively coupled to said channel.

10. The device of claim 2, wherein said carrier-collection structure also emits charge carriers of a second type, which can pass through said voltage-withstand region to said carrier-emission structure.

11. The device of claim 2, wherein said carrier-collection structure consists of a diffusion which has a conductivity type opposite to that of said voltage-withstand region.

12. The device of claim 2, wherein said carrier-emission structure includes a source diffusion, and said trench electrodes are electrically connected to said source region.

3. A lateral semiconductor device, comprising:

a carrier-emission structure; and

a voltage-withstand structure which is extended parallel to the surface of a monolithic semiconductor mass, and positioned so that carriers emitted by said carrier-emission structure pass laterally through said voltage-withstand structure, including a laterally tapered dielectric structure narrower near the drain end; and

trench electrodes which are also extended parallel to said surface, and which adjoin opposite sides of said voltage-withstand structure near said carrier-emission structure.

13. The device of claim 3, wherein said carrier-emission structure includes a source diffusion, a semiconductor channel which abuts said source diffusion, and a gate which is capacitively coupled to said channel.

14. The device of claim 3, further comprising an electrical contact which receives carriers emitted by said carrier-emission structure, after said carriers have passed through said voltage-withstand region.

15. The device of claim 3, wherein said carrier-emission structure includes a source diffusion, and said trench electrodes are electrically connected to said source region.