Data collection methods and apparatus

• US 6,542,835 B2
• Filed: 03/22/2001
• Issued: 04/01/2003
• Est. Priority Date: 03/22/2001
• Status: Expired due to Term

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: OnWafer Technologies, Inc. (KLA Corporation)
• Inventors: Mundt, Randall S.
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): MILLER, CRAIG S
• Application Number:
  US09/816,648
• Publication Number:
  US 20020165678A1
• Time in Patent Office: 740 Days
• Field of Search: 702/64, 702/65, 702/90, 702/104, 702/117
• US Class Current: 702/65
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring

Abstract

Information transfer is effected using a network of electrical signal conductors and sensors forming crosspoint connections. The sensors are capable of representing a measurement parameter as an electrical impedance. One embodiment of the present invention includes output electrical conductors, input electrical conductors, and sensors. Each of the sensors is connected with one of the output electrical conductors and one of the input electrical conductors so as to form an array of crosspoint connections. Application of electrical signals to the sensors and measurement of electrical signals from the sensors provide sufficient information to derive relative information from each sensor using algorithms based on equations for combining impedance. The embodiment may further include one or more reference elements connected with the output electrical conductors and with the input electrical conductors so as to form crosspoint connections. The reference elements have predetermined impedances and may be used to determine the impedance values for particular sensors.

Claims

1. An apparatus comprising:

at least two output electrical conductors;

at least one input electrical conductor;

at least two sensors, the sensors being capable of sensing a parameter and indicating the parameter as an electrical impedance;

the sensors being connected with the output electrical conductors and with the input electrical conductor so as to form an array of crosspoint connections;

a controller, the controller being connected with the output electrical conductors and with the input electrical conductor, the controller being capable of applying electrical signals to the output electrical conductors, the controller being capable of measuring electrical signals received from the input electrical conductor;

the controller being capable of at least one of;

a) storing information representative of the measurements of the electrical signals received from the input electrical conductors,

b) calculating the electrical impedance of each of the sensors using an algorithm, information of the electrical signals applied to the output electrical conductors, and measured electrical signals received from the input electrical conductors, and

c) transmitting information received from the sensors.

2. The apparatus of claim 1 wherein the at least one input electrical conductor comprises a plurality of input electrical conductors.

3. The apparatus of claim 2 further comprising a substrate for supporting the output electrical conductors, the input electrical conductors, and the sensors.

4. The apparatus of claim 2 further comprising a plurality of reference elements, the reference elements being connected with the output electrical conductors and with the input electrical conductors so as to form crosspoint connections.

5. The apparatus of claim 4 wherein each of the input electrical conductors has at least one reference element connected thereto.

6. The apparatus of claim 1 wherein the algorithm includes equations for summing impedances in series and summing impedances in parallel.

7. The apparatus of claim 1 wherein the sensors are capable of indicating the parameter as an electrical impedance that includes at least one of resistance, capacitance, and inductance.

8. The apparatus of claim 1 wherein the sensors comprise a parameter sensitive resistor.

9. The apparatus of claim 1 wherein the sensors comprise a thermistor.

10. The apparatus of claim 1 wherein the sensors comprise a photoresistor.

11. The apparatus of claim 1 wherein the sensors comprise a nonlinear electronic junction.

12. The apparatus of claim 1 wherein the sensors comprise a photodiode.

13. The apparatus of claim 1 wherein the sensors comprise an active electronic device.

14. The apparatus of claim 1 wherein the sensors comprise a MOSFET device.

15. The apparatus of claim 14 wherein the sensor impedance is a function of a voltage applied to the gate of the MOSFET device.

16. The apparatus of claim 1 wherein the sensors comprise a substantially continuous layer of parameter sensitive material shared by at least two of the sensors.

17. The apparatus of claim 1 wherein the controller comprises a microprocessor.

18. The apparatus of claim 1 further comprising a substrate, and wherein the sensors, the output electrical conductors, and the input electrical conductors are formed on the substrate.

19. The apparatus of claim 1 wherein the plurality of sensors comprise at least two types of sensors.

20. The apparatus of claim 1 wherein at least one of the sensors includes circuitry for converting the measured parameter into a corresponding electrical impedance.

21. A method for obtaining data from an array of sensors in a crosspoint network, the method being performed using sensors capable of representing parameters as electrical impedance, the method comprising the steps of:

applying a pattern of electrical signals to the sensors;

measuring electrical signals from the sensors;

deriving measurement data for each of the sensors using the measured electrical signals and algorithms.

22. The method of claim 21 wherein the individual response of one of the sensors is calculated from measuring electrical signals when the pattern of electrical signals comprises a plurality of electrical source states.

23. The method of claim 21 wherein the pattern of electrical signals includes voltages having at least two discrete magnitudes.

24. The method of claim 21 wherein the pattern of electrical signals includes currents having at least two discrete magnitudes.

25. The method of claim 21 wherein the method is carried out using input electrical conductors and output electrical conductors arranged to form the cross point network.

26. The method of claim 21 wherein the pattern of electrical signals includes alternating electrical signals.

27. An apparatus comprising:

a plurality of output electrical conductors;

a plurality of input electrical conductors;

a plurality of sensors capable of presenting a parameter as an electrical impedance, each of the sensors being connected with one of the output electrical conductors and one of the input electrical conductors so as to form an array of crosspoint connections; and

a plurality of reference elements, the reference elements being connected with the output electrical conductors and with the input electrical conductors so as to form crosspoint connections;

whereby application of electrical signals to the output electrical conductors and measurement of electrical signals at the input electrical conductors provide sufficient information to derive the measured property of each sensor using algorithms.