Devices containing permanent charge

• US 8,203,180 B2
• Filed: 05/24/2011
• Issued: 06/19/2012
• Est. Priority Date: 08/25/2008
• Status: Active Grant

• Current Assignee: MaxPower Semiconductor, Inc. (Vishay Intertechnology Incorporated)
• Original Assignee: MaxPower Semiconductor, Inc. (Vishay Intertechnology Incorporated)
• Inventors: Darwish, Mohamed N., Paul, Amit
• Primary Examiner(s): PRENTY, MARK V
• Application Number:
  US13/114,224
• Publication Number:
  US 20110220998A1
• Time in Patent Office: 392 Days
• Field of Search: 257/330, 257/341, 257/488, 257/490, 257/495, 257/E29.257
• US Class Current: 257/330
• CPC Class Codes: H01L 21/2256 through the applied layer
• CPC Class Codes: H01L 21/2257 the applied layer being silicon or silicide or SIPOS, e.g. polysilicon, porous silicon
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/2658 of a molecular ion, e.g. decaborane
• 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 29/0615 by the doping profile or the shape or the arrangement of the PN junction, or with supplementary regions, e.g. junction termination extension [JTE] LDD or drain offset regions H01L29/7833
• CPC Class Codes: H01L 29/0619 with a supplementary region doped oppositely to or in rectifying contact with the semiconductor containing or contacting region, e.g. guard rings with PN or Schottky junction
• CPC Class Codes: H01L 29/0638 for preventing surface leakage due to surface inversion layer, e.g. with channel stopper channel stoppers in combination with isolation region for integrated circuits H01L21/762
• CPC Class Codes: H01L 29/0653 adjoining the input or output region of a field-effect device, e.g. the source or drain region
• 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 29/402 Field plates
• CPC Class Codes: H01L 29/408 with an insulating layer with a particular dielectric or electrostatic property, e.g. with static charges or for controlling trapped charges or moving ions, or with a plate acting on the insulator potential or the insulator charges, e.g. for controlling charges effect or potential distribution in the insulating layer, or with a semi-insulating layer contacting directly the semiconductor surface
• CPC Class Codes: H01L 29/41741 for vertical or pseudo-vertical devices
• CPC Class Codes: H01L 29/42368 the thickness being non-uniform
• 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 29/7811 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/7827 Vertical transistors H01L29/7802, H01L29/78642 take precedence

Abstract

An edge termination structure includes a final dielectric trench containing permanent charge. The final dielectric trench is surrounded by first conductivity type semiconductor material (doped by lateral outdiffusion from the trenches), which in turn is laterally surrounded by second conductivity type semiconductor material.

Claims

1. An edge termination structure comprising:

a final dielectric trench containing permanent charge;

a junction region adjacent said final dielectric trench, said junction region having a first conductivity type; and

a termination region having a second conductivity type forming a termination junction with the junction region;

wherein said termination region includes at least one guard ring and at least one field plate.

2. The edge termination structure of claim 1, wherein said permanent charge is embedded cesium ions.

3. The edge termination structure of claim 1, wherein said at least one field plate has a stepped profile and overlies a patterned dielectric layer.

4. The edge termination structure of claim 1, further comprising both n-type and p-type guard ring diffusions within said termination region.

5. An edge termination structure comprising:

a final dielectric trench containing permanent charge;

a junction region adjacent said final dielectric trench, said junction region having a first conductivity type;

a termination region having a second conductivity type and forming a termination junction with the junction region; and

a combination of field plates with at least one guard ring diffusion within said termination region.

6. The edge termination structure of claim 5, wherein said permanent charge is embedded cesium.

7. An edge termination structure comprising:

a final dielectric trench containing permanent charge;

a junction region adjacent said final dielectric trench, said junction region having a first conductivity type;

a termination region having a second conductivity type and forming a termination junction with the junction region;

wherein said junction region extends into said termination region with decreasing doping density.

8. The edge termination structure of claim 7, wherein said permanent charge is embedded cesium ions.

9. The edge termination structure of claim 7, further comprising a field plate.

10. The edge termination structure of claim 7, further comprising a guard ring structure within said termination region.