Programmable logic array with vertical transistors

• US 6,208,164 B1
• Filed: 08/04/1998
• Issued: 03/27/2001
• Est. Priority Date: 08/04/1998
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Forbes, Leonard, Noble, Wendell P.
• Primary Examiner(s): Tokar, Michael
• Assistant Examiner(s): Le, Don Phu
• Application Number:
  US09/129,047
• Time in Patent Office: 966 Days
• Field of Search: 257/302, 257/202, 257/330, 257/320, 326/39, 326/41, 326/44, 326/101, 326/102
• US Class Current: 326/41
• CPC Class Codes: H01L 27/11803 using field effect technology

Abstract

A programmable logic array is provided. The programmable logic array includes first and second logic planes. The first logic plane receives a number of input signals. The first logic plane includes a plurality of vertical transistors arranged in rows and columns that are interconnected to provide a number of logical outputs. The second logic plane also includes a number of vertical transistors arranged in rows and columns that receive the outputs of the first logic plane and that are interconnected to produce a number of logical outputs such that the programmable logic array implements a logical function.

Claims

1. A programmable logic array, comprising:

a first logic plane that receives a number of input signals, the first logic plane having a plurality of vertical transistors, each having a first source/drain region, a body region and a second source/drain region, wherein the vertical transistors include one gate that is formed in a trench adjacent to the body region and have a body contact that is formed adjacent to the body region on a side opposite the gate, wherein the body contact is pulsed in synchronization with the gate, and wherein the vertical transistors are arranged in rows and columns that are interconnected to provide a number of logical outputs; and

a second logic plane having a number of vertical transistors arranged in rows and columns that receive the outputs of the first logic plane and that are interconnected to produce a number of logical outputs such that the programmable logic array implements a logical function.

2. The programmable logic array of claim 1, wherein the first logic plane and the second logic plane each comprise NOR planes.

3. The programmable logic array of claim 1, wherein the vertical transistors each comprise a first source/drain region, a body region and a second source/drain region that are vertically aligned in a monocrystalline semiconductor pillar and that extend outwardly from a semiconductor substrate.

4. The programmable logic array of claim 3, wherein the vertical transistors in the second logic plane include one gate that is formed in a trench adjacent to the body region.

5. The programmable logic array of claim 3, wherein the vertical transistors in the second logic plane include one gate that is formed in a trench adjacent to the body region and a body contact that is formed adjacent to the body region on a side opposite the gate.

6. The programmable logic array of claim 3, wherein the vertical transistors include first and second gates that are formed in trenches adjacent to the body region on opposite sides of the pillar.

7. The programmable logic array of claim 3, wherein the trench separates adjacent rows of pillars and the trench houses one input line that is coupled to gates of selected transistors on either side of the trench.

8. The programmable logic array of claim 3, wherein the trench separates adjacent rows of pillars and the trench houses two input lines that are each coupled to gates of selected transistors on one side of the trench.

9. The programmable logic array of claim 3, wherein the trench separates adjacent rows of pillars and the trench houses an input line that is coupled to gates of selected transistors on one side of the trench and a body contact line that is coupled to the body region of each pillar on the other side of the trench.

10. The programmable logic array of claim 1, wherein the substrate is a bulk semiconductor.

11. The programmable logic array of claim 1, wherein the working surface of the substrate includes an insulating layer formed on top of an underlying semiconductor.

12. The programmable logic array of claim 1, wherein the programmable logic array is operatively coupled to a computer system.

13. The programmable logic array of claim 5, wherein the body contact is maintained at a substantially constant voltage.

14. The programmable logic array of claim 5, wherein the body contact in the second logic plane is pulsed in synchronization with the gate.

15. The programmable logic array of claim 3, wherein the body region comprises a lightly doped body region such that the transistor functions as a fully depleted transistor.

16. The programmable logic array of claim 3, wherein the first source/drain regions of the pillars of the array are coupled together.

17. A computer system, comprising:

at least one input/output device;

a memory; and

a central processing unit, the central processing unit coupled to the memory and the at least one input/output device, the central processing unit including at least one programmable logic array including;

a first logic plane that receives a number of input signals, the first logic plane having a plurality of vertical transistors, each having a first source/drain region, a body region and a second source/drain region, wherein the vertical transistors include one gate that is formed in a trench adjacent to the body region and have a body contact that is formed adjacent to the body region on a side opposite the gate, wherein the body contact is pulsed in synchronization with the gate, and wherein the vertical transistors are arranged in rows and columns that are interconnected to provide a number of logical outputs; and

a second logic plane having a number of vertical transistors arranged in rows and columns that receive the outputs of the first logic plane and that are interconnected to produce a number of logical outputs such that the programmable logic array implements a logical function for the central processing unit.

18. The computer system of claim 17, wherein the first logic plane and the second logic plane each comprise NOR planes.

19. The computer system of claim 17, wherein the vertical transistors in the second logic plane each comprise a first source/drain region, a body region and a second source/drain region that are vertically aligned in a monocrystalline semiconductor pillar and that extend outwardly from a semiconductor substrate.

20. The computer system of claim 19, wherein the vertical transistors in the second logic plane include one gate that is formed in a trench adjacent to the body region.

21. The computer system of claim 19, wherein the vertical transistors in the second logic plane include one gate that is formed in a trench adjacent to the body region and a body contact that is formed adjacent to the body region on a side opposite the gate.

22. The computer system of claim 19, wherein the vertical transistors include first and second gates that are formed in trenches adjacent to the body region on opposite sides of the pillar.

23. The computer system of claim 19, wherein the trench separates adjacent rows of pillars and the trench houses one input line that is coupled to gates of selected transistors on either side of the trench.

24. The computer system of claim 19, wherein the trench separates adjacent rows of pillars and the trench houses two input lines that are each coupled to gates of selected transistors on one side of the trench.

25. The computer system of claim 19, wherein the trench separates adjacent rows of pillars and the trench houses an input line that is coupled to gates of selected transistors on one side of the trench and a body contact line that is coupled to the body region of each pillar on the other side of the trench.

26. The computer system of claim 17, wherein the substrate is a bulk semiconductor.

27. The computer system of claim 17, wherein the working surface of the substrate includes an insulating layer formed on top of an underlying semiconductor.

28. The computer system of claim 21, wherein the body contact is maintained at a substantially constant voltage.

29. The computer system of claim 19, wherein the body region comprises a lightly doped body region such that the transistor functions as a fully depleted transistor.

30. The computer system of claim 19, wherein the first source/drain regions of the pillars of the array are coupled together.