IP Library Granted Patent US 9,859,448
Granted Patent B2
US 9,859,448 · App. 15/149,020 · Granted Jan 2, 2018

Single-event burnout (SEB) hardened power schottky diodes, and methods of making and using the same

Inventor: John R. Scarpulla (Rancho Palos Verdes, CA)
Assignee: The Aerospace Corporation
H01L29/872H01L21/0217H01L21/02057H01L21/0262H01L21/0273H01L21/02532H01L21/02595H01L21/266H01L21/28537H01L21/31116H01L23/291H01L23/3171H01L27/0248H01L28/20H01L29/0623H01L29/36H01L29/47H01L29/66143H03K17/08H03K2017/0803
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Quick Facts
Patent No.
US 9,859,448
App. No.
15/149,020
Granted
Jan 2, 2018
Kind
B2
Abstract

Under one aspect, a power Schottky diode includes a cathode; a semiconductor disposed over the cathode, the semiconductor including at least a first region and a second region, the second region defining a guard ring; an anode disposed over the first region and at least a portion of the guard ring, the anode including a metal, a junction between the anode and the first region defining a Schottky barrier; and an oxide disposed over the guard ring. Additionally, the power Schottky diode can include a resistive material disposed over at least a portion of the guard ring and at least a portion of the oxide. The resistive material can inhibit a flow of holes from the guard ring to the anode following a heavy ion strike to the guard ring. The anode further can be disposed over at least a portion of, or the entirety of, the resistive material.

Claims (48)

1. A power Schottky diode, including:

a cathode;

a semiconductor disposed over the cathode, the semiconductor including at least a first region and a second region, the second region defining a guard ring;

an anode disposed over the first region and at least a portion of the guard ring, the anode including a metal, a junction between the anode and the first region defining a Schottky barrier;

an oxide disposed over a portion of the guard ring;

a resistive material disposed over at least a portion of the guard ring and at least a portion of the oxide, the resistive material being disposed between the guard ring and the anode at all portions of the guard ring not covered by the oxide so as to inhibit all direct contact between the guard ring and the anode, the resistive material having a resistance of at least 100 Ω-cm so as to inhibit a flow of holes from the guard ring to the anode following a heavy ion strike to the guard ring.

2. The power Schottky diode of claim 1 , wherein the anode further is disposed over at least a portion of the resistive material.

3. The power Schottky diode of claim 2 , wherein the anode further is disposed over the entirety of the resistive material.

4. The power Schottky diode of claim 1 , wherein the oxide includes:

a first, relatively high quality and relatively thin oxide material disposed over the guard ring; and

a second, relatively low quality and relatively thick oxide material disposed over the first oxide material.

5. The power Schottky diode of claim 1 , wherein the resistive material includes polysilicon.

6. The power Schottky diode of claim 1 , further including a substrate defining the cathode, the semiconductor being epitaxially disposed over the substrate.

7. The power Schottky diode of claim 6 , wherein:

the second region is doped with a P-type dopant so as to define the guard ring; and

a third region of the semiconductor is doped with an N-type dopant.

8. A method of forming a power Schottky diode, the method including:

providing a cathode;

providing a semiconductor disposed over the cathode, the semiconductor including at least a first region and a second region, the second region defining a guard ring;

providing an anode disposed over the first region and at least a portion of the guard ring, a junction between the anode and the first region defining a Schottky barrier;

providing an oxide disposed over the guard ring; and

disposing a resistive material over at least a portion of the guard ring and at least a portion of the oxide, the resistive material being disposed between the guard ring and the anode at all portions of the guard ring not covered by the oxide so as to inhibit all direct contact between the guard ring and the anode, the resistive material having a resistance of at least 100 Ω-cm so as to inhibit a flow of holes from the guard ring to the anode following a heavy ion strike to the guard ring.

9. The method of claim 8 , wherein the anode further is disposed over at least a portion of the resistive material.

10. The method of claim 9 , wherein the anode further is disposed over the entirety of the resistive material.

11. The method of claim 8 , wherein providing the oxide includes:

disposing a first, relatively high quality and relatively thin oxide material over the guard ring; and

disposing a second, relatively low quality and relatively thick oxide material over the first oxide material.

12. The method of claim 8 , wherein the resistive material includes polysilicon.

13. The method of claim 8 , further including providing a substrate defining the cathode, and wherein providing the semiconductor includes epitaxially disposing the semiconductor over the substrate.

14. The method of claim 13 , including doping the second region with a P-type dopant so as to define the guard ring, and doping a third region of the semiconductor with an N-type dopant.

15. A method including:

providing a power Schottky diode including:

a cathode;

a semiconductor disposed over the cathode, the semiconductor including at least a first region and a second region, the second region defining a guard ring;

an anode disposed over the first region and at least a portion of the guard ring, the anode including a metal, a junction between the anode and the first defining a Schottky barrier;

an oxide disposed over the guard ring;

a resistive material disposed over at least a portion of the guard ring and at least a portion of the oxide, the resistive material being disposed between the guard ring and the anode at all portions of the guard ring not covered by the oxide so as to inhibit all direct contact between the guard ring and the anode, the resistive material having a resistance of at least 100 Ω-cm; and

inhibiting by the resistance of the resistive material a flow of holes from the guard ring to the anode following a heavy ion strike to the guard ring.

16. The method of claim 15 , wherein the anode further is disposed over at least a portion of the resistive material.

17. The method of claim 16 , wherein the anode further is disposed over the entirety of the resistive material.

18. The method of claim 15 , wherein the oxide includes:

a first, relatively high quality and relatively thin oxide material disposed over the guard ring; and

a second, relatively low quality and relatively thick oxide material disposed over the first oxide material.

19. The method of claim 15 , wherein the resistive material includes polysilicon.

20. The method of claim 15 , further including providing a substrate defining the cathode, and wherein the semiconductor is epitaxially disposed over the substrate.

21. The method of claim 15 , wherein:

the second region is doped with a P-type dopant so as to define the guard ring; and

a third region of the semiconductor is doped with an N-type dopant.

Assignments (2)
CONFIRMATORY LICENSE Recorded Apr 10, 2019
From: THE AEROSPACE CORPORATION
To: GOVERNMENT OF THE UNITED STATES AS REPRESENTED BY THE SECRETARY OF THE AIR FORCE
Reel/Frame 048845/0341 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 9, 2016
From: SCARPULLA, JOHN R.
To: THE AEROSPACE CORPORATION
Reel/Frame 038521/0797 →
Continuity (1)
Related Publication 20170323982A1 · Nov 9, 2017