Semiconductor bidirectional switching device

• US 6,943,408 B2
• Filed: 05/06/2004
• Issued: 09/13/2005
• Est. Priority Date: 01/23/2001
• Status: Expired due to Term

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Wu, Yujing, Pearse, Jeffrey
• Primary Examiner(s): LOKE, STEVEN HO YIN
• Application Number:
  US10/840,486
• Publication Number:
  US 20040207027A1
• Time in Patent Office: 495 Days
• Field of Search: 257/393, 257/329, 257/330, 257/331, 257/328
• US Class Current: 257/329
• CPC Class Codes: H01L 29/0847 of field-effect transistors with insulated gate H01L29/0653 takes precedence; with a passive supplementary region between source or drain and substrate related to punch-through, capacity or isolation phenomena H01L29/1079; with LDD or DDD structure H01L29/7833; for thin film transistors H01L29/78618
• CPC Class Codes: H01L 29/0878 Impurity concentration or distribution
• CPC Class Codes: H01L 29/4232 with insulated gate
• CPC Class Codes: H01L 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/4238 characterised by the surface lay-out
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236

Abstract

A semiconductor switching device (10) is formed on a semiconductor substrate (12) having a trench (44) formed on one of its surfaces (42). A control electrode (32) activates a wall of the trench to form a conduction channel (36). A first conduction electrode (40) is disposed on the semiconductor substrate to have a first doped region (34) for receiving a current and a second doped region (24) for routing the current to the conduction channel.

Claims

1. A bidirectional switch, comprising:

a semiconductor substrate having a first surface for forming a trench;

a control structure formed in the trench to enable a conduction channel in response to a control signal, and having a dielectric layer along a wall of the trench and a control electrode adjacent to the dielectric layer, wherein the dielectric layer extends onto the first surface, and wherein the dielectric layer has a first thickness along the wall, and wherein the dielectric layer has a second thickness along the first surface, wherein the second thickness is greater than the first thickness, and wherein the control electrode extends above the first surface;

a first conduction electrode having a first layer formed at the first surface for receiving a current and a second layer underlying the first layer for coupling the current to the conduction channel, wherein the first layer is spaced a predefined distance from the control electrode; and

a second conduction electrode disposed at a lower portion of the trench for receiving the current from the conduction channel.

2. The bidirectional switch of claim 1, wherein the second conduction electrode extends from the lower portion of the trench to a second surface of the semiconductor substrate.

3. The bidirectional switch of claim 2, wherein a breakdown voltage between the control electrode and the second conduction electrode is greater than eight volts.

4. The bidirectional switch of claim 1, wherein a breakdown voltage between the control electrode and the first conduction electrode is greater than eight volts.

5. The bidirectional switch of claim 1, wherein the predefined distance is greater than approximately 0.4 micrometers.

6. The bidirectional switch of claim 1, wherein the second conduction electrode comprises a drain extension region overlying a drain region.

7. A bidirectional switch, comprising:

a semiconductor substrate having a first surface for forming a trench;

a control structure formed in the trench to enable a conduction channel in response to a control signal, and having a dielectric layer along a wall of the trench and a control electrode adjacent to the dielectric layer;

a first conduction electrode having a first layer formed at the first surface for receiving a current and a second layer underlying the first layer for coupling the current to the conduction channel, wherein the first layer is spaced apart from the trench and spaced a predefined distance from the control structure; and

a second conduction electrode disposed at a lower portion of the trench for receiving the current from the conduction channel.

8. The bidirectional switch of claim 7 wherein the second conduction electrode extends from the lower portion of the trench to a second surface of the semiconductor substrate.

9. The bidirectional switch of claim 7 wherein the predefined distance is greater than approximately 0.4 micrometers.

10. The bidirectional switch of claim 7 wherein the second conduction electrode comprises a drain extension region overlying a drain region.

11. The bidirectional switch of claim 10 wherein the drain extension region comprises a buried drain extension region.