Methods and apparatus for low distortion parameter measurements

• US 7,299,148 B2
• Filed: 07/08/2005
• Issued: 11/20/2007
• Est. Priority Date: 07/10/2004
• Status: Expired due to Fees

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: OnWafer Technologies, Inc. (KLA Corporation)
• Inventors: Welch, Michael, Freed, Mason L., Spanos, Costas J., Hunt, Dean, Poolla, Kameshwar
• Primary Examiner(s): Ramos-Feliciano; Eliseo
• Assistant Examiner(s): Charioui; Mohamed
• Application Number:
  US11/177,922
• Publication Number:
  US 20060052969A1
• Time in Patent Office: 865 Days
• Field of Search: 702/62, 702/99, 702/104, 702/116, 702/117, 702130-132, 702/136, 702/183, 257/620, 738/620.45
• US Class Current: 702/130
• CPC Class Codes: G01K 1/18 for reducing thermal inertia
• CPC Class Codes: H05K 1/147 at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit H05K1/148 takes precedence
• CPC Class Codes: H05K 1/148 Arrangements of two or more hingeably connected rigid printed circuit boards, i.e. connected by flexible means

Abstract

This invention seeks to provide methods and apparatus that can improve the accuracy of measured parameter data used for processing workpieces. One aspect of the present invention includes methods of measuring process conditions with low distortion of the measurements caused by the measuring apparatus. The measurements include data for applications such as data for monitoring, controlling, and optimizing processes and process tools. Another aspect of the present invention includes apparatus for measuring substantially correct data for applications such as generating data for monitoring, controlling, and optimizing processes and process tools.

Claims

1. A sensor apparatus comprising:

a base having a substantially rigid surface;

at least one sensor in physical contact with the base; and

an electronics module comprising components for information-processing and a support structure for suspending at least one of the components away from the surface of the base, the at least one sensor being connected with the components so as to provide signals representing measurements of a process parameter, the support structure having at least one of;

a thermal resistance so that the measurements are substantially unperturbed by the presence of the electronics module and the electronics module is substantially undamaged by heat transferred from the base to the electronics module and

a thermal mass so that the measurements from the sensors are substantially unperturbed by the presence of the electronics module.

2. The sensor apparatus of claim 1 further comprising a printed circuit board interconnecting the components for information processing, the printed circuit board being flexibly coupled to the support structure so that the components for information-processing can be moved from a first position to a second position.

3. The sensor apparatus of claim 2 further comprising a latch mechanism for holding the printed circuit board in the first position.

4. The sensor apparatus of claim 1, wherein at least a portion of the support structure is substantially flexible.

5. The sensor apparatus of claim 1, wherein the support structure comprises at least a substantially flexible portion and the flexible portion is connected with the base.

6. The sensor apparatus of claim 1, wherein at least a portion of the support structure is substantially flexible so that at least one of the components suspended away from the base can be held in a closed position or in an opened position.

7. The sensor apparatus of claim 1, wherein the components for information processing and the support structure are flexibly coupled so that the components for information-processing can be moved from a first position to a second position.

8. The sensor apparatus of claim 1 further comprising a flexible printed circuit board interconnecting the components for information processing, the printed circuit board being flexibly coupled to the support structure so that the components for information-processing can be moved from a first position to a second position.

9. The sensor apparatus of claim 1 wherein the support structure comprises a flexible printed circuit board connected with the at least one sensor so as to receive the signals.

10. The sensor apparatus of claim 1 further comprising circuitry for electrical communication between the components for information processing and the at least one sensor.

11. The sensor apparatus of claim 1 wherein the base comprises a substantially whole semiconductor wafer.

12. The sensor apparatus of claim 1 wherein the base comprises a substrate for a lithography mask.

13. The sensor apparatus of claim 1 wherein the at least one sensor comprises a temperature sensor.

14. The sensor apparatus of claim 1 wherein the at least one sensor comprises a plurality of temperature sensors selected from the group consisting of resistor temperature dependent sensors, thermistors, and thermocouples.

15. The sensor apparatus of claim 1 wherein the at least one sensor comprises a plurality of sensors selected from the group consisting of etch rate sensor, deposition rate sensor, thermal flux sensor, optical radiation sensor, and resistivity sensor.

16. A method of making low distortion measurements of a process parameter in a process chamber for processing workpieces, the process chamber being connected with a robot having a robot arm for loading and unloading the workpieces, the method comprising the steps of:

A. providing a sensor apparatus having a substrate, a plurality of sensors, at least one electronic component for information processing supported on a printed circuit board, an elongated ribbon cable or an elongated flexible circuit board, and a fastener;

the plurality of sensors being supported on the substrate, the elongated ribbon cable or the elongated flexible circuit board being electrically connected with the sensors and the at least one electronic component;

the fastener being coupled to the printed circuit board or to the elongated ribbon cable or the elongated flexible circuit board so that the printed circuit board can be removably attached to the robot;

B. using the fastener to attach the circuit board to the robot arm;

C. using the robot to place the substrate in the process chamber;

D. positioning the robot arm so as to create a predetermined separation between the substrate and the printed circuit board;

E. establishing the process conditions for the parameter measurements;

F. measuring the parameters with the sensors and collecting the measurements with the at least one electronic component;

G. using the robot to remove the substrate from the process chamber; and

H. detaching the circuit board from the robot arm.

17. The method of claim 16 wherein the robot arm remains in the process chamber or in an adjacent chamber during step F.

18. The method of claim 16 wherein the robot arm remains in the process chamber or is withdrawn from the process chamber during step F.

19. The method of claim 16 wherein the process chamber has a port;

the method further comprising the step of providing a gate for opening and closing the port;

wherein step C comprises placing the substrate in the process chamber through the port;

wherein step D comprises withdrawing the robot arm from the process chamber so that the elongated ribbon cable or the elongated flexible circuit board is extended through the port and closing the gate on the elongated ribbon cable or the elongated flexible circuit board; and

wherein step G comprises opening the gate.

20. A method of using an electronics module for a sensor apparatus for attachment to a base, the base having at least one sensor mounted thereon, the electronics module being connected with the at least one sensor so as to receive signals from the sensor, the electronics module having:

a bottom section comprising a circuit board having wiring and a plurality of electrical contacts;

a remote section comprising a circuit board and a plurality of components for electronically processing information;

a first electrical connector configured so as to make reversible electrical connections, a second electrical connector configured so as to make reversible electrical connections, and a middle section comprising a structure for transmitting information, the middle section having a first end and a second end, the first end of the middle section being coupled to the bottom section with the first electrical connector, and the second and other middle section being coupled to the remote section with the second electrical connector, wherein, the bottom section physically connects with the base, the method comprising the steps of;

configuring the middle section so as to comprise an elongated ribbon cable or an elongated printed circuit board;

using the electronics module for a first application;

replacing the elongated ribbon cable or elongated printed circuit board with a short ribbon cable or a short printed circuit board; and

using the electronics module for a second application.

21. The method of claim 20 further comprising the step of configuring the middle section so as to comprise an elongated ribbon cable or an elongated printed circuit board after using the electronics module for the second application.

22. A sensor apparatus for measuring temperatures for processing silicon wafers, the sensor apparatus comprising:

a substantially whole silicon wafer;

a plurality of temperature sensors in physical contact with the silicon wafer so as to provide temperature measurements; and

at least one electronics module mounted on the silicon wafer, the electronics module comprising an information processor, a power supply, a flexible integrated circuit board comprising polyimide, and a support structure comprising polyimide, the information processor, the power supply, and the sensors being interconnected via the flexible circuit board so that the information processor can receive power from the power supply and signals from the sensors, the support structure being flexibly coupled to the flexible circuit board, the support structure having electrical circuits for transmitting signals from the sensors to the flexible circuit board, the support structure having a flexible portion for physical contact with the silicon wafer, the support structure being configured for suspending the information processor and the power supply away from the surface of the silicon wafer, the support structure being configured so as to provide a rate of conductive heat transfer between the silicon wafer and the electronics module so that the temperature measurements from the sensors are substantially unperturbed by the presence of the electronics module and the electronics module is substantially undamaged by heat transferred from the base to the electronics module, the support structure having a latch mechanism for holding the printed circuit board in a predetermined position.

23. An electronics module for a sensor apparatus for mounting on a base, the base having at least one sensor mounted thereon, the electronics module being connected with the at least one sensor so as to receive signals from the sensor, the electronics module comprising:

a bottom section comprising a flexible circuit board having wiring and a plurality of electrical contacts;

a top section comprising a circuit board and a plurality of components for electronically processing information; and

a middle section comprising a flexible circuit board or a ribbon cable coupled between the bottom section and the top section, wherein, the bottom section physically contacts the base for support and the middle section extends away from the base; and

a substantially planar induction coil mounted on the bottom section, the coil being configured for receiving inductively coupled power, the coil being connected with the top section so as to provide power to at least one of the plurality of components.