Thyristor-based device over substrate surface

• US 6,690,038 B1
• Filed: 07/23/2002
• Issued: 02/10/2004
• Est. Priority Date: 06/05/1999
• Status: Expired due to Fees

• Current Assignee: T-Ram, LLC
• Original Assignee: T-Ram, Inc.
• Inventors: Cho, Hyun-jin, Horch, Andrew, Robins, Scott, Nemati, Farid
• Primary Examiner(s): CRANE, SARA W
• Application Number:
  US10/200,987
• Time in Patent Office: 567 Days
• Field of Search: 257/133, 257/147, 257/155, 365/180
• US Class Current: 257/133
• CPC Class Codes: H01L 27/0617 comprising components of the field-effect type H01L27/0251 takes precedence
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 29/41716 Cathode or anode electrodes for thyristors
• CPC Class Codes: H01L 29/42308 Gate electrodes for thyristors
• CPC Class Codes: H01L 29/74 Thyristor-type devices, e.g. having four-zone regenerative action two-terminal thyristors H01L29/87

Abstract

A semiconductor device having a thyristor is arranged in a manner that reduces or eliminates manufacturing difficulties commonly experienced in the formation of such devices, as well as facilitates the implementation of the semiconductor device in a variety of applications. According to an example embodiment of the present invention, a thyristor is formed having some or all of the body of the thyristor extending above a substrate surface of a semiconductor device. The semiconductor device includes at least one transistor having source/drain regions formed in the substrate prior to the formation of the thyristor. One or more layers of material are deposited on the substrate surface and used to form a portion of a body of the thyristor that includes anode and cathode end portions. Each end portion is formed having a base region and an emitter region, and at least one of the end portions includes a portion that is in the substrate and electrically coupled to the transistor. A control port is formed capacitively coupled to at least one of the base regions.

Claims

1. A thyristor-based semiconductor device comprising:

a semiconductor substrate having an upper surface;

a transistor having a gate over the upper surface and first and second source/drain regions having a portion thereof in the substrate and below the upper surface; and

a thyristor extending over the upper surface and having a body with first and second emitter regions separated by first and second base regions respectively adjacent to the first and second emitter regions and a portion of the thyristor extending over the gate, the first emitter region being electrically coupled in series with the first source/drain region, and a control port adapted for capacitively coupling to the body for facilitating control of current flow therein.

2. The thyristor-based semiconductor device of claim 1, wherein the thyristor is a thin capacitively-coupled thyristor.

3. The thyristor-based semiconductor device of claim 1, wherein the first emitter region and the first source/drain region are the same region.

7. The thyristor-based semiconductor device of claim 1, wherein the control port is disposed laterally adjacent to the thyristor body.

8. The thyristor-based semiconductor device of claim 7, wherein the control port is disposed laterally around a portion of the thyristor body.

9. The thyristor-based semiconductor device of claim 1, wherein the control port is adapted to capacitively couple a signal to the first base region.

10. The thyristor-based semiconductor device of claim 1, wherein the control port is adapted to switch the thyristor body between current-blocking and current-passing states.

11. The thyristor-based semiconductor device of claim 1, wherein the second source/drain region is coupled to a bit line and wherein the second emitter region is coupled to a reference voltage line.

12. The thyristor-based semiconductor device of claim 11, wherein the first emitter region is adapted for storing data.

13. The thyristor-based semiconductor device of claim 12, wherein the thyristor-based semiconductor device is configured and arranged for storing, retrieving and erasing data at the first emitter region in response to signals applied to at least one of:

the control port, the gate, the reference voltage line and the bit line.

14. The thyristor-based semiconductor device of claim 1, wherein the thyristor is adapted to operate as part of a power thyristor.

15. The thyristor-based semiconductor device of claim 1, wherein the thyristor is adapted to operate as part of an output driver.

16. The thyristor-based semiconductor device of claim 1, wherein the thyristor is adapted to operate as part of a power management device.

17. The thyristor-based semiconductor device of claim 1, wherein the thyristor is adapted to operate as part of an electrostatic discharge circuit adapted to latch and shunt power from circuitry coupled to the thyristor.

18. The thyristor-based semiconductor device of claim 1, wherein the transistor gate is adapted to apply a voltage to the thyristor as a back gate.

19. The thyristor-based semiconductor device of claim 1, wherein the first base region has two vertical portions and wherein the control port is disposed laterally between the two vertical portions.

20. The thyristor-based semiconductor device of claim 1, further comprising a dielectric material over the transistor gate, the dielectric material being adapted to reduce parasitic capacitance between the thyristor control port and the transistor gate.

21. The thyristor-based semiconductor device of claim 20, further comprising a nitride etch stop over the transistor gate.

22. The thyristor-based semiconductor device of claim 21, at least one of the first and second base regions of the thyristor extends over the first emitter region and laterally over the nitride etch stop.

23. The thyristor-based semiconductor device of claim 1, further comprising a hard mask over the transistor gate, the hard mask being adapted to electrically insulate the transistor gate from the thyristor.

24. The thyristor-based semiconductor device of claim 1, further comprising an insulative material over the transistor gate and an etch stop over the insulative material, the etch stop being adapted to reduce capacitive coupling between the thyristor control port and the transistor gate.

25. The thyristor-based semiconductor device of claim 1, wherein the control port is adapted to capacitively couple a signal to the thyristor to control current passing through the thyristor independently from any MOS inversion channel formation against a portion of the thyristor to which the control port is capacitively coupled.

26. The thyristor-based semiconductor device of claim 1, further comprising a first insulative material between the transistor gate and the upper surface and a second insulative material between the thyristor control port and the upper surface, the second insulative material being thicker than the first insulative material.

27. A method of using the thyristor-based semiconductor device of claim 1, the method comprising:

controlling the gate and the control port for storing, retrieving and manipulating data at the first emitter region.

28. The method of claim 27, wherein controlling the gate and the control port for storing, retrieving and manipulating data at the first emitter region includes controlling a bit line coupled to the second source/drain region and controlling a reference voltage line coupled to the second emitter region for storing, retrieving and manipulating data at the first emitter region.

4. A thyristor-based semiconductor device comprising:

a semiconductor substrate having an upper surface;

a transistor having a gate over the upper surface and first and second source/drain regions having a portion thereof in the substrate and below the upper surface; and

a thyristor extending over the upper surface and having a body with first and second emitter regions separated by first and second base regions respectively adjacent to the first and second emitter regions wherein at least a portion of the thyristor body is disposed in a trench having sidewalls in a layer over the transistor, the first emitter region being electrically coupled in series with the first source/drain region, and a control port adapted for capacitively coupling to the body for facilitating control of current flow therein.

5. The thyristor-based semiconductor device of claim 4, wherein the layer over the transistor comprises dielectric material.

6. The thyristor-based semiconductor device of claim 4, wherein the sidewalls comprise etched portions of the layer over the transistor.