Self-bootstrapping field effect diode structures and methods

• US 8,633,521 B2
• Filed: 01/06/2010
• Issued: 01/21/2014
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics NV
• Inventors: Ankoudinov, Alexei, Rodov, Vladimir
• Primary Examiner(s): Nhu, David
• Application Number:
  US12/683,425
• Publication Number:
  US 20100271851A1
• Time in Patent Office: 1,476 Days
• Field of Search: 257/401, 257/512, 257/E27.028, 257/E27.009, 257/E27.029, 257/E27.325, 257/288, 257/142, 257/143, 257/144, 257/124, 257/127, 257/294, 257/E21.051, 257/E21.053, 257/E21.352, 257/E21.366, 257/E21.435, 361/58, 361/111, 438/213, 438/279
• US Class Current: 257/288
• CPC Class Codes: H01L 27/0811 MIS diodes
• CPC Class Codes: H01L 27/0814 Diodes only
• CPC Class Codes: H01L 29/7412 the device being a diode
• CPC Class Codes: H01L 29/861 Diodes

Abstract

A two terminal device which can be used for the rectification of the current. Internally it has a regenerative coupling between MOS gates of opposite type and probe regions. This regenerative coupling allows to achieve performance better than that of ideal diode.

Claims

1. A semiconductor diode comprising:

first and second field-effect-gated current-conducting devices of opposite respective conductivity types, the first and second devices each comprising gates, sources, and drains, the first and second devices having respective sources thereof connected together, the second field-effect-gated current-conducting device further comprising a drift region and a semiconductor region formed within the drift region, the gate of the first field-effect-gated current-conducting device being connected to the semiconductor region of the drift region of the second field-effect-gated current-conducting device;

said first and second field-effect-gated current-conducting devices each having respective drain terminals, the drain terminal of the first field-effect-gated current-conducting device being connected to a first external terminal of the semiconductor diode and the drain terminal of the second field-effect-gated current-conducting device being connected to a second external terminal of the semiconductor diode, the first and second externally connected to provide anode and cathode connections of the semiconductor diode, respectively;

wherein the semiconductor diode has no external electrical connection other than the anode and cathode connections,

wherein said drift region of the first field-effect-gated current-conducting device is substantially lateral, and a drift region of the second field-effect-gated current-conducting device extends vertically downward to a backside drain connection structure of the first field-effect-gated current-conducting device.

2. A semiconductor device comprising:

a first field-effect device of a first conductivity type, the first field-effect device comprising a first gate region, a first source region, a first drain region, a first drift region, a semiconductor region formed in the first drift region, a first conductive layer electrically connected to the first gate region, a second conductive layer electrically connected to the semiconductor region of the first drift region, and a third conductive layer electrically connected to the first source region, the first, second, and third conductive layers each being a different conductive layer; and

a second field-effect device of a second conductivity type different from the first conductivity type, the second field-effect device comprising a second gate region, a second source region, and a second drain region, the second conductive layer being electrically connected to the second gate region and the third conductive layer being electrically connected to the second source region.

3. The semiconductor device of claim 2, wherein the semiconductor device is a two-terminal device having two external terminals, wherein a first external terminal is coupled to the first drain region and a second external terminal is coupled to the second drain region.

4. The semiconductor device of claim 3, wherein the semiconductor device is arranged as a diode, the first external terminal being an anode of the diode and the second external terminal being a cathode of the diode.

5. The semiconductor device of claim 2, wherein the first drift region in which the semiconductor region is formed is a drift region to carry current between the first source region and the first drain region when the first field-effect device is in a conductive state.

6. The semiconductor device of claim 2, wherein the first field-effect device further comprises a body region, where the first source region is formed in the body region and the first drift region is a portion of the body region.

7. The semiconductor device of claim 2, wherein the second conductive layer is not electrically connected to the first conductive layer.

8. The semiconductor device of claim 2, wherein the first source region is arranged to produce a depletion region in the first field-effect device when the first field-effect device is in a nonconductive state, and the semiconductor region is positioned in the first drift region such that the semiconductor region is within the depletion region when the first field-effect device is in the nonconductive state.

9. The semiconductor device of claim 2, wherein the first source region comprises a semiconductor region of the first conductivity type and the semiconductor region comprises a semiconductor material of the first conductivity type.

10. The semiconductor device of claim 9, wherein the semiconductor region is more heavily doped than the first source region.

11. The semiconductor device of claim 2, wherein each of the first, second, and third conductive layers is a metal layer.