Avalanche Diode Having an Enhanced Defect Concentration Level and Method of Making the Same

Patent metadata

Field	Value
Publication number	US-2016111413-A1
Application number	US-201514978882-A
Country	US
Kind code	A1
Filing date	Dec 22, 2015
Priority date	Jan 21, 2008
Publication date	Apr 21, 2016
Grant date	—

Abstract

The invention relates to an avalanche diode that can be employed as an ESD protection device. An avalanche ignition region is formed at the p-n junction of the diode and includes an enhanced defect concentration level to provide rapid onset of avalanche current. The avalanche ignition region is preferably formed wider than the diode depletion zone, and is preferably created by placement, preferably by ion implantation, of an atomic specie different from that of the principal device structure. The doping concentration of the placed atomic specie should be sufficiently high to ensure substantially immediate onset of avalanche current when the diode breakdown voltage is exceeded. The new atomic specie preferably comprises argon or nitrogen, but other atomic species can be employed. However, other means of increasing a defect concentration level in the diode depletion zone, such as an altered annealing program, are also contemplated.

First claim

What is claimed is:

1 . A method of forming an avalanche diode, the method comprising:
forming a first diode region next to a second diode region in a substrate, the second diode region oppositely doped from the first diode region; forming an avalanche ignition region surrounding a junction of the first diode region and the second diode region; and forming a depletion zone surrounding the junction of the first diode region with the second diode region, wherein the depletion zone is wider than the avalanche ignition region.

2 . The method as claimed in claim 1 , wherein the avalanche ignition region has a defect concentration level greater than a defect concentration level of the first diode region and the second diode region.

3 . The method as claimed in claim 1 , wherein the depletion zone is created by applying a reverse voltage to the avalanche diode.

4 . The method as claimed in claim 1 , wherein the avalanche ignition region comprises an atomic species different from an atomic species forming a principle structure of the first diode region and the second diode region.

5 . The method as claimed in claim 4 , wherein the atomic species is a neutral atomic species.

6 . The method as claimed in claim 5 , wherein the neutral atomic species comprises argon.

7 . The method as claimed in claim 5 , wherein the neutral atomic species comprises one of nitrogen and carbon.

8 . The method as claimed in claim 5 , wherein the neutral atomic species comprises germanium or gold.

9 . The method as claimed in claim 1 , further comprising forming the first diode region on a silicon substrate.

10 . The method as claimed in claim 1 , wherein forming an avalanche ignition region comprises forming dislocations in the substrate.

11 . The method as claimed in claim 1 , wherein forming an avalanche ignition region comprises forming dislocations in the substrate using an implantation process.

12 . An electronic system, comprising:
an output pad coupled to an internal circuit; a first electrostatic discharge (ESD) diode comprising an anode and a cathode, wherein the first ESD diode is coupled to the output pad and to a first bias voltage supply rail; a second ESD diode comprising an anode and a cathode, wherein the second ESD diode is coupled to the output pad and to a second bias voltage supply rail; and a bipolar transistor coupled between the first and second bias voltage supply rails, the bipolar transistor comprising an avalanche ignition region.

13 . The electronic system as claimed in claim 12 , wherein the avalanche ignition region comprises a second atomic species different from a first atomic species of a principal structure of the first and second ESD diodes.

14 . The electronic system as claimed in claim 13 , wherein the second atomic species comprises a neutral atomic species.

15 . The electronic system as claimed in claim 14 , wherein the neutral atomic species comprises argon, nitrogen, carbon, germanium or gold.

16 . The electronic system as claimed in claim 12 , wherein the avalanche ignition region comprises an enhanced defect concentration level than a principle structure of the first and second ESD diodes.

Assignees

• Infineon Technologies Ag

Inventors

• Schneider Jens
• Esmark Kai
• Wendel Martin

Classifications

• H10P36/03

  within silicon bodies · CPC title

• H10P30/208

  of electrically inactive species · CPC title

• H10P30/204

  into Group IV semiconductors · CPC title

• H10W42/80

  protecting against overcurrent or overload, e.g. fuses or shunts (integrated devices comprising arrangements for electrical protection H10D89/60) · CPC title

• H10D62/128

  Anode regions of diodes · CPC title