Closed loop control for reliability

• US 9,026,241 B2
• Filed: 02/24/2012
• Issued: 05/05/2015
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Yang, Wen-Cheng, Kao, Chung-En, Chou, You-Hua, Tsai, Ming-Chih, Chiang, Chen-Chia, Lin, Bo-Hung, Lin, Chin-Hsiang
• Primary Examiner(s): Masinick, Michael D
• Application Number:
  US13/404,676
• Publication Number:
  US 20130226327A1
• Time in Patent Office: 1,166 Days
• Field of Search: 700/108, 700/121, 700/182
• US Class Current: 700/108
• CPC Class Codes: G05B 2219/37533 Real time processing of data acquisition, monitoring
• CPC Class Codes: G05B 2219/45031 Manufacturing semiconductor wafers
• CPC Class Codes: G05B 23/0237 based on parallel systems, e.g. comparing signals produced at the same time by same type systems and detect faulty ones by noticing differences among their responses
• CPC Class Codes: G05B 9/03 with multiple-channel loop, i.e. redundant control systems

Abstract

The present disclosure relates to semiconductor tool monitoring system having multiple sensors configured to concurrently and independently monitor processing conditions of a semiconductor manufacturing tool. In some embodiments, the disclosed tool monitoring system comprises a first sensor system configured to monitor one or more processing conditions of a semiconductor manufacturing tool and to generate a first monitoring response based thereupon. A redundant, second sensor system is configured to concurrently monitor the one or more processing conditions of the manufacturing tool and to generate a second monitoring response based thereupon. A comparison element is configured to compare the first and second monitoring responses, and if the responses deviate from one another (e.g., have a deviation greater than a threshold value) to generate a warning signal. By comparing the first and second monitoring responses, errors in the sensor systems can be detected in real time, thereby preventing yield loss.

Claims

1. A semiconductor manufacturing tool monitoring system, comprising:

a first sensor system configured to measure one or more processing conditions of a semiconductor manufacturing tool and to generate a first monitoring response based thereupon;

a second sensor system configured to measure the one or more processing conditions of the semiconductor manufacturing tool and to generate a second monitoring response based thereupon;

a comparison element configured to compare the first monitoring response to the second monitoring response to identify a deviation between the first and second monitoring responses is indicative of an error in the first or second sensor systems;

a control system configured to receive a warning signal from the comparison element and upon receiving the warning signal to suspend operation of the semiconductor manufacturing tool; and

wherein the comparison element is configured to generate the warning signal if the first monitoring response deviates from the second monitoring response, which is measured at a substantially same time as the first monitoring response, by a value greater than a threshold value.

2. The monitoring system of claim 1, wherein the first sensor system comprises:

a first sensor configured to measure the one or more processing conditions of the semiconductor manufacturing tool;

a first amplifier configured to receive and amplify an output of the first sensor to generate the first monitoring response; and

a first comparator configured to compare the first monitoring response to a tool setting value and to generate an adjustment call if the first monitoring response violates the tool setting value.

3. The monitoring system of claim 2, wherein the adjustment call is provided to a closed control loop configured to adjust the one or more processing conditions of the semiconductor manufacturing tool.

4. The monitoring system of claim 3, wherein the closed control loop comprises:

a PID controller configured to receive the adjustment call and to generate a control signal therefrom; and

a driver configured to receive the control signal and based thereupon to make an adjustment to one or more manufacturing tool components of the semiconductor manufacturing tool that adjust the one or more processing conditions.

5. The monitoring system of claim 2, wherein the second sensor system comprises:

a second sensor configured to measure the one or more processing conditions of the semiconductor manufacturing tool concurrent with the first sensor;

a second amplifier configured to receive and amplify an output of the second sensor to generate the second monitoring response; and

a second comparator configured to compare the first monitoring response to the second monitoring response and to generate the warning signal if the first and second monitoring responses deviate by an amount greater than the threshold value.

6. The monitoring system of claim 1, wherein the comparison element comprises a fault detection and classification (FDC) system configured to receive the first and second monitoring responses, to detect the deviation between the first and second monitoring responses, and to take action to prevent damage to a semiconductor body within the semiconductor manufacturing tool if the deviation is detected.

7. The monitoring system of claim 1, wherein the one or more processing conditions comprise one or more of a temperature and a gas flow rate.

8. The monitoring system of claim 1, wherein the first sensor system and the second sensor system comprise different types of sensors.

9. A semiconductor manufacturing tool, comprising:

a semiconductor manufacturing tool;

a first sensor system configured to measure one or more processing conditions of the semiconductor manufacturing tool and to generate a first monitoring response based thereupon, wherein the first sensor drives a closed control loop configured to adjust the one or more processing conditions of the semiconductor manufacturing tool;

a second sensor system configured to measure the one or more processing conditions of the semiconductor manufacturing tool at a substantially same time as the first sensor system and to generate a second monitoring response based thereupon; and

a comparator configured to compare the first and second monitoring responses, to generate a warning signal if the first and second monitoring responses deviate from one another by an amount greater than a threshold value, and upon receiving the warning signal to suspend operation of the semiconductor manufacturing tool.

10. The manufacturing tool of claim 9, wherein the first sensor system comprises:

a first sensor configured to measure the one or more processing conditions of the semiconductor manufacturing tool;

a first amplifier configured to receive and amplify an output of a first sensor to generate the first monitoring response; and

a first comparator configured to compare the first monitoring response to a tool setting value and to generate an adjustment call if the first monitoring response violates the tool setting value, wherein the adjustment call is provided to the closed control loop configured to adjust the one or more processing conditions of the semiconductor manufacturing tool.

11. The manufacturing tool of claim 10, wherein the closed control loop comprises:

a PID controller configured to receive the adjustment call and to generate a control signal therefrom; and

a driver configured to receive the control signal and based thereupon to make an adjustment to one or more manufacturing tool components of the semiconductor manufacturing tool that adjust the one or more processing conditions.

12. The manufacturing tool of claim 9, wherein the second sensor system comprises:

a second sensor configured to measure the one or more processing conditions of the semiconductor manufacturing tool concurrent with the first sensor; and

a second amplifier configured to receive and amplify an output of the second sensor to generate the second monitoring response.

13. The manufacturing tool of claim 9, wherein the one or more processing conditions comprises a temperature or a gas flow rate.

14. A method for reliably monitoring processing conditions of a semiconductor manufacturing tool, comprising:

operating a first sensor system to generate a first monitoring response corresponding to one or more processing conditions of a manufacturing tool;

operating a second sensor system to generate a second monitoring response corresponding to the one or more processing conditions of the manufacturing tool;

comparing the first monitoring response to the second monitoring response to determine if an error is present in the first or second sensor systems;

comparing the first monitoring response to a tool setting value;

adjusting one or more processing conditions of the manufacturing tool if the first monitoring response violates the tool setting value; and

generating a warning signal if the first monitoring response deviates from the second monitoring response, which is measured at a substantially same time as the first monitoring response, by more than a threshold value.

15. The method of claim 14, further comprising:

suspending operation of the semiconductor manufacturing tool if the warning signal is generated.

16. The method of claim 14, wherein the one or more processing conditions comprises a temperature or a gas flow rate.