SYSTEM AND METHOD FOR WIRELESS AND DYNAMIC INTRA-PROCESS MEASUREMENT OF INTEGRATED CIRCUIT PARAMETERS

• US 20090240452A1
• Filed: 03/24/2008
• Published: 09/24/2009
• Est. Priority Date: 03/24/2008
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: International Business Machines Corporation
• Inventors: Ventrone, Sebastian T., Perri, Anthony J., Hall, Ezra D.B., Anemikos, Theodoros E., Erturk, Mete, Corson, Phillip L.
• Granted Patent: US 8,239,811 B2
• Time in Patent Office: Days
• US Class Current: 702/76
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32
• CPC Class Codes: H01L 23/64 Impedance arrangements
• 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: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

Disclosed are embodiments of a system and a method that allow for wireless and dynamic intra-process (i.e., during and/or between process steps) measurements of integrated circuit parameters. The embodiments incorporate the use of a passive circuit, such as an inductor-capacitor-resistor (LCR) circuit resonator, that has a predetermined sensitivity to process variations in one or more physical or electrical integrated circuit parameters. The passive circuit can be wirelessly interrogated between and/or process steps. Then, the actual behavior exhibited by the passive circuit in response to the interrogation is compared to the expected behavior of an optimal circuit in the absence of process variations in order to determine the one or more parameters. Also disclosed is an embodiment of an exemplary passive circuit that can be used to implement the disclosed system and method embodiments.

Claims

1. A system for wireless measurement of integrated circuit parameters, said system comprising:

an interrogation unit adapted to wirelessly detect a type of circuit behavior;

a wafer comprising a passive circuit with a predetermined sensitivity to process variations in at least one integrated circuit parameter,

wherein said at least one integrated circuit parameter comprises at least one of a physical parameter and an electrical parameter, and

wherein said passive circuit is adapted to exhibit said type of circuit behavior in response to a stimulus; and

an analyzer adapted to determine a value for said at least one integrated circuit parameter based on a difference between expected behavior and actual behavior exhibited by said passive circuit in response to said stimulus, as detected by said interrogation unit.

2. The system according to claim 1, all the limitations of which are incorporated by reference, further comprising a stimulus source connected to said interrogation unit and adapted to generate and apply said stimulus to said passive circuit through said interrogation unit.

3. The system according to claim 1, all the limitations of which are incorporated by reference, further comprising a sensor in communication with said interrogation unit and adapted to sense and measure said actual behavior detected by said interrogation unit.

4. The system according to claim 1, all the limitation of which are incorporated by reference, wherein said analyzer is further adapted to determine values for multiple integrated circuit parameters based on said actual behavior.

5. The system according to claim 1, all the limitation of which are incorporated by reference, further comprising a space separating said passive circuit from said interrogation unit, wherein said space comprises one of air and a dielectric material.

6. The system according to claim 1, all the limitations of which are incorporated by reference,

wherein said system further comprises an additional interrogation unit similarly adapted to wirelessly detect said type of circuit behavior,

wherein said wafer further comprises an additional passive circuit with a different predetermined sensitivity to said process variations in said at least one integrated circuit parameter,

wherein said additional passive circuit is similarly adapted to exhibit said type of circuit behavior in response to said stimulus, and

wherein said analyzer is further adapted to more accurately determine said value for said at least one integrated circuit parameter based also on a difference between expected behavior and actual behavior exhibited by said additional passive circuit in response to said stimulus, as detected by said additional interrogation unit.

7. The system according to claim 1, all the limitations of which are incorporated by reference,

wherein said wafer further comprises an additional passive circuit with said predetermined sensitivity to said process variations in said at least one integrated circuit parameter, and

wherein said additional passive circuit is similarly adapted to exhibit said type of circuit behavior in response to said stimulus but is tuned differently than said passive circuit so that said interrogation unit can simultaneously interrogate said passive circuit and said additional passive circuit and so that said analyzer can more accurately determine said value for said at least one integrated circuit parameter based also on a difference between expected behavior and actual behavior exhibited by said additional passive circuit in response to said stimulus, as detected by said interrogation unit.

8. A passive resonator with a predetermined sensitivity to process variations in at least one integrated circuit parameter, said passive resonator comprising:

a substrate;

at least one structure with resistive behavior on said substrate;

at least one structure with inductive behavior on said substrate; and

at least one structure with capacitive behavior on said substrate, wherein said at least one structure with resistive behavior, said at least one structure with capacitive behavior and said at least one structure with inductive behavior are interconnected and configured to form an inductor-capacitor-resistor (LCR) circuit that exhibits, in response to radio frequency energy, resonant behavior that varies in a predictable manner as a function of said process variations in said at least one integrated circuit parameter, wherein said at least one integrated circuit parameter comprises one of a physical parameter and an electrical parameter.

9. The passive circuit according to claim 8, all the limitations of which are incorporated by reference, wherein said inductor-capacitor-resistor (LCR) circuit comprises a three-layer structure comprising a dielectric layer between a polysilicon resistor layer and a metal inductor layer such that said polysilicon resistor layer, said dielectric layer and said metal inductor layer in combination form said at least one structure with capacitive behavior.

10. The passive circuit according to claim 9, all the limitations of which are incorporated by reference, further comprising a contact extending vertically through said dielectric layer and electrically connecting said at least one structure with resistive behavior and said at least one structure with inductive behavior.

11. The passive circuit according to claim 8, all the limitations of which are incorporated by reference, wherein said at least one structure with resistive behavior comprises a polysilicon resistor structure comprising a first section and a plurality of second sections extending radially from said first section.

12. The passive circuit according to claim 8, all the limitations of which are incorporated by reference, wherein said at least one structure with inductive behavior comprises a spiral-shaped metal wire with an inner end electrically connected to said at least one structure with resistive behavior.

13. The passive circuit according to claim 8, all the limitation of which are incorporated herein by reference, wherein said at least one integrated circuit parameter comprises at least one of polysilicon sheet resistance, contact height and metal sheet resistance.

14. A system for wireless measurement of integrated circuit component parameters, said system comprising:

an interrogation unit adapted to wirelessly detect resonant behavior;

a wafer comprising a passive resonator with a predetermined sensitivity to process variations in at least one integrated circuit parameter,

wherein said at least one integrated circuit parameter comprises at least one of a physical parameter and an electrical parameter, and

wherein said passive resonator is adapted to exhibit said resonant behavior in response to radio frequency energy; and

an analyzer adapted to determine a value for said at least one integrated circuit parameter based on a difference between expected resonant behavior and actual resonant behavior exhibited by said passive resonator in response to said radio frequency energy, as detected by said interrogation unit.

15. The system according to claim 14, all the limitations of which are incorporated by reference, further comprising:

wherein said interrogation unit comprises wire coil with an input node adapted to receive said radio frequency energy at one end and with an output node at an opposite end, and

wherein, when said wire coil is place in close proximity to said passive resonator, said wire coil is inductively coupled to said resonator.

16. The system according to claim 15, all the limitations of which are incorporated by reference, wherein said radio frequency energy comprises a radio frequency pulse, and wherein said system further comprises:

a pulse generator adapted to generate and apply said radio frequency pulse to said input node; and

a spectrum analyzer electrically connected between said output node and said analyzer, wherein said spectrum analyzer is adapted to sense and measure said actual response at said output node, to generate a frequency spectrum based on said actual response and to communicate said frequency spectrum to said analyzer.

17. The system according to claim 15, all the limitations of which are incorporated by reference, wherein said radio frequency energy comprises a sine voltage, and wherein said system further comprises:

a sine sweep generator adapted to generate and apply said sine voltage to said input node; and

a spectrum analyzer electrically connected between said output node and said analyzer, wherein said spectrum analyzer is adapted sense and measure said actual response at said output node, to generate a phase spectrum and an amplitude spectrum based on said actual response and to communicate said phase spectrum and said amplitude spectrum to said analyzer.

18. A method for wireless measurement of integrated circuit parameters, said method comprising:

providing a wafer comprising a passive circuit that exhibits, in response to a stimulus, a type of behavior capable of being wirelessly detected and that further has a predetermined sensitivity to process variations in at least one integrated circuit parameter, wirelessly interrogating said passive circuit to determine actual behavior exhibited by said passive circuit in response to said stimulus; and

determining a value for said at least one integrated circuit parameter based on a difference between expected behavior and said actual behavior, wherein said at least one integrated circuit parameter comprises at least one of a physical parameter and an electrical parameter.

19. The method according to claim 18, all the limitation of which are incorporated by reference, further comprising, before said providing of said wafer, designing said passive circuit and simulating behavior of said passive circuit in the absence of process variations and in the presence of different processes variations.

20. The method according to claim 18, all the limitations of which are incorporated by reference, further comprising, before said determining, normalizing said actual behavior to account for at least one of scaling, offset and noise errors.