PHASE CHANGE MATERIAL BASED TEMPERATURE SENSOR

• US 20090001336A1
• Filed: 06/29/2007
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: McMahon, Robert, Habib, Nazmul, Lam, Chung Hon
• Granted Patent: US 7,795,605 B2
• Time in Patent Office: Days
• US Class Current: 257/2
• CPC Class Codes: G01K 11/06 using melting, freezing, or softening
• CPC Class Codes: G01K 7/16 using resistive elements resistive elements per se H01C, H01L
• CPC Class Codes: H10B 63/30 comprising selection components having three or more electrodes, e.g. transistors
• CPC Class Codes: H10N 70/063 by etching of pre-deposited switching material layers, e.g. lithography
• CPC Class Codes: H10N 70/231 based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• CPC Class Codes: H10N 70/8825 Selenides, e.g. GeSe
• CPC Class Codes: H10N 70/8828 Tellurides, e.g. GeSbTe
• CPC Class Codes: H10N 70/884 Other compounds of groups 13-15, e.g. elemental or compound semiconductors

Abstract

A block of phase change material located in a semiconductor chip is reset to an amorphous state. The block of phase change material may be connected to an internal resistance measurement circuit that can transmit the measured resistance data to input/output pads either in an analog output format or in a digital output format. Depending on the ambient temperature, the resistance of the block of phase change material changes. By measuring a fractional resistance change compared to the resistance of the phase change material at a calibration temperature, the temperature of the region around the phase change material can be accurately measured. A logic decoder and an input/output circuit may be employed between the internal resistance measurement circuit and the input/output pads. A plurality of temperature sensing circuits containing phase change material blocks may be employed in the semiconductor chip to enable an accurate temperature profiling during chip operation.

Claims

1. A semiconductor circuit comprising:

a block of phase change material located in a semiconductor chip;

at least two input/output pads on said semiconductor chip; and

a metal wiring connecting said block and said at least two input/output pads.

2. The semiconductor circuit of claim 1, wherein said block of phase change material abuts a semiconductor component selected from the group consisting of source and drain regions, an emitter, a collector, a gate, a diode, and a resistor.

3. The semiconductor circuit of claim 1, wherein said block of phase change material abuts a semiconductor substrate.

4. A semiconductor circuit comprising:

a block of phase change material located in a semiconductor chip;

at least two input/output pads on said semiconductor chip;

a metal wiring connecting said block and said at least two input/output pads; and

a resistance measurement circuit connected to said block and said at least two input/output pads.

5. The semiconductor circuit of claim 4, further comprising a programming transistor connected to said block and said metal wiring, wherein said programming transistor is capable of resetting said block of phase change material to an amorphous state by passing current through said block.

6. The semiconductor circuit of claim 5, further comprising an amorphous state resetting circuit, wherein said amorphous state resetting circuit incorporates said programming transistor and controls current through said block.

7. The semiconductor circuit of claim 6, further comprising a logic decoder and input/output circuit connected to said amorphous state resetting circuit, said resistance measurement circuit, and said at least two input/output pads.

8. The semiconductor circuit of claim 6, wherein said phase change material comprises an alloy of a chalcogen element with at least one non-chalcogen element, said chalcogen element is selected from the group consisting of Te, Se, and S, and said at least one non-chalcogen element is selected from the group consisting of Ge, Sb, Bi, Pb, Sn, As, Si, P, Ga, In, and Ag.

9. The semiconductor circuit of claim 6, wherein said block of phase change material abuts a semiconductor component selected from the group consisting of source and drain regions, an emitter, a collector, a gate, a diode, and a resistor.

10. The semiconductor circuit of claim 6, wherein said block of phase change material abuts a semiconductor substrate.

11. A method of measuring an operating temperature of a semiconductor chip comprising:

characterizing temperature dependency of the resistivity of an amorphous phase change material and generating a fitting function;

designing and manufacturing a semiconductor circuit having a block of the phase change material and current measurement capability through said block;

subjecting said semiconductor chip to an operating condition and measuring an operating condition current through said block;

calculating an operation condition resistivity from said measured operating condition current; and

calculating a temperature at which said fitting function generates said calculated operating condition resistivity.

12. The method of claim 11, further comprising modifying said fitting function by matching said fitting function with a measured value of resistivity of said phase change material at a standard condition prior to calculating said temperature.

13. The method of claim 12, wherein said measured value of resistivity at said standard condition is derived from a standard condition current measurement through said block.

14. The method of claim 11, wherein said fitting function is a polynomial of temperature having at least one segment and defined below a crystallization temperature.

15. The method of claim 11, further comprising resetting said block to an amorphous state prior to said subjecting of said semiconductor chip to said operating condition.

16. A method of forming a semiconductor structure comprising:

forming at least one semiconductor component selected from the group consisting of source and drain regions, an emitter, a collector, a gate, a diode, and a resistor;

depositing a layer of phase change material directly on said at least one semiconductor component;

forming a block of said phase change material by lithographic patterning and etching of said layer of said phase change material;

forming at least two metal contacts to said block of said phase change material; and

forming a metal wiring connecting said at least two metal contacts to at least two input/output pads.

17. The method of claim 16, wherein said block of said phase change material abuts said at least one semiconductor component.

18. The method of claim 16, wherein said block of phase change material abuts a semiconductor substrate.

19. The method of claim 16, further comprising forming at least another semiconductor circuit component which is capable of providing a programming current through said block of said phase change material, wherein said programming current melts said block and resets the state of said block to an amorphous state upon cooling.

20. The method of claim 16, further comprising forming at least another semiconductor circuit component which is capable of providing a measurement current through said block of said phase change material, wherein the temperature of said block upon passing said measurement current increases by less than 10 degrees Celsius.