FUSE ELEMENT PROGRAMMING CIRCUIT AND METHOD

• US 20180005705A1
• Filed: 09/11/2017
• Published: 01/04/2018
• Est. Priority Date: 03/25/2014
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: HALL, Jefferson W.
• Granted Patent: US 10,340,020 B2
• Time in Patent Office: Days
• CPC Class Codes: G11C 17/16 using electrically-fusible links
• CPC Class Codes: G11C 17/18 Auxiliary circuits, e.g. for writing into memory
• CPC Class Codes: G11C 5/147 Voltage reference generators, voltage or current regulators; Internally lowered supply levels; Compensation for voltage drops G11C5/141 takes precedence
• CPC Class Codes: H01L 23/5228 Resistive arrangements or effects of, or between, wiring layers other resistive arrangements H01L23/647
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10B 20/20 Programmable ROM [PROM] devices comprising field-effect components H10B20/10 takes precedence
• CPC Class Codes: H10B 20/25 One-time programmable ROM [OTPROM] devices, e.g. using electrically-fusible links
• CPC Class Codes: H10B 20/65 of memory structures of the ROM only type
• CPC Class Codes: H10B 99/00 Subject matter not provided for in other groups of this subclass

Abstract

In one embodiment, a programming circuit is configured to form a programming current for a silicide fuse element by using a non-silicide programming element.

Claims

1. A circuit for programming a fuse element comprising:

a memory cell having the fuse element that includes a first semiconductor material body region and a silicide layer;

a programming circuit configured to form a programming current to program the fuse element;

a current mirror, of the programming circuit, having a first transistor coupled at a node to a second transistor of the current mirror;

a programming element configured to control a value of the programming current, the programming element having a second semiconductor material body region but not a silicide layer;

a reference generation circuit coupled in series between the node and the programming element;

the programming circuit configured to control the programming current to a first value responsively to a value of the programming element and to subsequently control the programming current to a different value responsively to a value of the fuse element.

2. The circuit of claim 1 wherein a resistivity of the programming element is substantially representative of a resistivity of the first semiconductor material body region of the fuse element.

3. The circuit of claim 1 wherein the programming element includes a doped polysilicon body region that is substantially devoid of a silicide material.

4. The circuit of claim 1 wherein the programming circuit includes a means for forming a value of the programming current to cause electro-migration of silicide material overlying a portion of the first semiconductor material body region of the fuse element and increasing a resistivity of the fuse element.

5. The circuit of claim 1 wherein the reference generation circuit separates the programming element from the first transistor.

6. The circuit of claim 1 wherein the reference generation circuit includes a reference transistor having a first current carrying electrode coupled to the node and a second current carrying electrode coupled to a first terminal of the programming element.

7. The circuit of claim 1 wherein a resistivity of the programming element is substantially representative of a resistivity of the first semiconductor material body region of the fuse element prior to alloying the silicide layer with the first material semiconductor body region.

22. The circuit of claim 6 wherein the reference generation circuit including an amplifier having an output coupled to a control electrode of the reference transistor.

23. The circuit of claim 22 wherein the amplifier has a first input coupled to receive a reference voltage and a second input coupled to the second current carrying electrode of the reference transistor.

8. A method of forming a programming circuit for a fuse element comprising:

forming the fuse element having a first semiconductor layer and a silicide layer wherein the first semiconductor layer has a first resistivity and the silicide layer has a second resistivity;

forming a body region of a programming element from substantially the first semiconductor layer and to have a third resistivity that is substantially equal to the first resistivity wherein the body region is substantially devoid of a silicide material; and

configuring the programming circuit to control a value of a programming current through the fuse element using the programming element.

9. The method of claim 8 further including forming the programming element to include a second semiconductor layer having the third resistivity.

10. The method of claim 8 wherein configuring the programming circuit to control the value of the programming current includes configuring a control circuit to form the programming current to cause substantially a void in the silicide layer but not in the first semiconductor layer.

11. The method of claim 10 further including configuring the control circuit to form the programming current to increase the first resistivity to a fourth resistivity and substantially not form a void in the first semiconductor layer.

12. The method of claim 8 wherein configuring the programming circuit to control the value of the programming current includes configuring the control circuit to form the programming current with a value to increase the first resistivity to a fourth resistivity and to decrease the programming current to a second value responsively to forming the fourth resistivity wherein the second value is greater than zero.

13. A method of forming an OTP programming circuit comprising:

forming a fuse element having a resistance, a first semiconductor layer formed from a semiconductor material, and a silicide layer wherein the first semiconductor layer has a body region having a body resistivity that is substantially a first resistivity, and the silicide layer has a second resistivity that is less than the first resistivity;

configuring a programming circuit having a reference circuit configured to apply a voltage to a programming element to form a control current that flows through the programming element and through the reference circuit;

forming a current mirror of the programming circuit to conduct the control current and form a programming current; and

configuring the programming circuit to control a value of the programming current through the fuse element responsively to a body region of the programming element wherein the body region of the programming element is formed from substantially the semiconductor material and wherein the programming current increases the resistance of the fuse element.

16. The method of claim 13 further including forming the body region of the programming element from the semiconductor material that is substantially devoid of a silicide material.

18. The method of claim 13 wherein configuring the programming circuit to control the value of the programming current includes configuring the programming circuit to form the value of the programming current to result in a current density in the body region of the fuse element that causes electro-migration of silicide material.

19. The method of claim 13 wherein configuring the programming circuit to control the value of the programming current includes configuring the programming circuit to control the value of the programming current to result in a current density in the body region of the fuse element that causes electro-migration of dopants in the body region of the fuse element.

20. The method of claim 13 wherein configuring the programming circuit to control the value of the programming current includes configuring the programming circuit to form the value of the programming current to result in a current density of approximately 1E7 to 1E8 amps/cm² in the body region of the fuse element.

21. The method of claim 13 wherein configuring the programming circuit to control the value of the programming current includes configuring a control circuit to form the programming current with a value to increase the first resistivity to a fourth resistivity and to decrease the programming current to a second value responsively to forming the fourth resistivity wherein the second value is greater than zero.

14. (canceled)

15. (canceled)

17. (canceled)