LOT PROCESS ORDER MODIFICATION TO IMPROVE DETECTION OF MANUFACTURING EFFECTS

• US 20120109351A1
• Filed: 10/28/2010
• Published: 05/03/2012
• Est. Priority Date: 10/28/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Yamartino, John M.
• Granted Patent: US 8,676,367 B2
• Time in Patent Office: Days
• US Class Current: 700/101
• CPC Class Codes: H01L 21/67276 Production flow monitoring, e.g. for increasing throughput program-control systems per se G05B19/00, e.g. total factory control G05B19/418
• CPC Class Codes: H01L 21/67745 characterized by movements or sequence of movements of transfer devices

Abstract

A system for lot based, multi-step wafer manufacturing processes is provided and includes a transfer apparatus, disposed among tools for performing respective process steps on each wafer of each lot of wafers transferred thereto, the transfer apparatus being configured to transfer each lot from a current tool to a next tool in accordance with a process step sequence, a dispatcher operably coupled to the transfer apparatus to modify the lot order in response to a modification condition detection, a measurement unit configured to receive each wafer of each fully processed lot and to collect measurements therefrom and a processor disposed in signal communication with the dispatcher and the measurement unit to analyze the measurements relative to the lot order for evidence that a process step of a corresponding tool is responsible for performance effects.

Claims

1. A system for lot based, multi-step wafer manufacturing processes, the system comprising:

a transfer apparatus, disposed among tools for performing respective process steps on each wafer of each lot of wafers transferred thereto, the transfer apparatus being configured to transfer each lot from a current tool to a next tool in accordance with a process step sequence;

a dispatcher operably coupled to the transfer apparatus to modify the lot order in response to a modification condition detection;

a measurement unit configured to receive each wafer of each fully processed lot and to collect measurements therefrom; and

a processor disposed in signal communication with the dispatcher and the measurement unit to analyze the measurements relative to the lot order for evidence that a process step of a corresponding tool is responsible for performance effects.

2. The system according to claim 1, wherein the tools comprise tools for executing plasma vapor or chemical vapor deposition (PVD or CVD), ion implantation, lithography, etching, stripping, cleaning, annealing, rapid thermal processing (RTP), furnace processing chemical mechanical planarization (CMP) and/or metrology.

3. The system according to claim 1, further comprising a plurality of detectors to monitor current conditions and to issue a signal to the dispatcher indicative of the monitoring.

4. The system according to claim 1, wherein the modification condition is a queue length of multiple lots.

5. The system according to claim 1, wherein the dispatcher modifies the lot order by randomization.

6. The system according to claim 1, wherein the dispatcher modifies the lot order by reversal.

7. The system according to claim 1, wherein the dispatcher forces a queue of multiple lots and then modifies the lot order.

8. A system for lot based, multi-step wafer manufacturing processes, the system comprising:

a transfer apparatus, disposed among tools for performing respective process steps on each wafer of each lot of wafers transferred thereto, the transfer apparatus being configured to transfer each lot from a current tool to a next tool in accordance with a process step sequence;

a dispatcher operably coupled to the transfer apparatus to modify the lot order in response to a lot order constraint and to modify the lot order in response to a modification condition detection;

a measurement unit configured to receive each wafer of each fully processed lot and to collect measurements therefrom; and

a processor disposed in signal communication with the dispatcher and the measurement unit to analyze the measurements relative to the lot order for evidence that a process step of a corresponding tool is responsible for performance effects.

9. The system according to claim 8, wherein the lot order constraint comprises a priority indication.

10. The system according to claim 8, wherein the tools comprise tools for executing plasma vapor or chemical vapor deposition (PVD or CVD), ion implantation, lithography, etching, stripping, cleaning, annealing, rapid thermal processing (RTP), furnace processing chemical mechanical planarization (CMP) and/or metrology.

11. The system according to claim 8, further comprising a plurality of detectors to monitor current conditions and to issue a signal to the dispatcher indicative of the monitoring.

12. The system according to claim 8, wherein the modification condition is a queue length of multiple lots.

13. The system according to claim 8, wherein the dispatcher modifies the lot order by randomization.

14. The system according to claim 8, wherein the dispatcher modifies the lot order by reversal.

15. The system according to claim 8, wherein the dispatcher forces a queue of multiple lots and then modifies the lot order.

16. A method of operating a system for lot based, multi-step wafer manufacturing processes, the method comprising:

at selected process steps and for available lots, determining a modified lot order that is different from a lot order in a prior process step;

processing the lots according to the modified lot order;

collecting measurements from wafers within the lots that have been fully processed; and

analyzing the measurements relative to lot order sequence data for evidence that a process step is responsible for performance effects.

17. The method according to claim 16, wherein the available lots are identified in accordance with a lot order constraint.

18. The method according to claim 16, wherein the determining comprises randomizing the lot order.

19. The method according to claim 16, wherein the determining comprises reversing the lot order.

20. The method according to claim 16, wherein the determining comprises forcing a queue of multiple lots and then modifying the lot order.