Response Policies to Process Module Failure in Single-Arm Cluster Tools Subject to Wafer Residency Time Constraints

IEEE Trans. Semicond. Manufact.

Zhou

et al. 2015

The trends of increasing wafer diameter and smaller lot sizes have led to more transient periods in wafer fabrication. For some wafer fabrication processes, such as atomic layer deposition, wafers need to visit some process modules for a number of times, instead of once, thus leading to a so-called revisiting process. Most previous studies on cluster tool scheduling focus on steady state at which cluster tools repeat identical cycles. Research on transient processes of dual-arm cluster tools with wafer revisiting processes becomes urgently needed for high-performance wafer fabrication. In order to speed up start-up transient processes, this paper adopts a program evaluation and review technique for the analysis of start-up transient processes and develops optimization algorithms for their scheduling of dual-arm cluster tools. Then, their complexity is analyzed. Finally, illustrative examples are given to show the applications of the proposed method.

Section: Discussionmentioning

confidence: 99%

Scheduling and Analysis of Start-Up Transient Processes for Dual-Arm Cluster Tools With Wafer Revisiting

Pan

IEEE Trans. Semicond. Manufact.

Zhou

et al. 2015

“…Hence, a response policy is necessary to transfer SCH 0 to SCH 1 such that the tool operates feasibly all the time. For such a case, response policies are developed in [22]. In other cases, after a failure, there is no feasible cyclic schedule.…”

Section: Schedulability Conditionsmentioning

confidence: 99%

“…It is known that if there are parallel PMs at a step and when one of them fails, it may be able to operate continuously in a performance degraded way [13] and [26]. After a failure, if the tool is schedulable, response policies are proposed in [22] to control the system such that the wafers in a tool can be completed without violating wafer residency time constraints. However, in some other cases, when one of parallel PMs fails, there is no feasible cyclic schedule.…”

mentioning

confidence: 99%

How to Respond to Process Module Failure in Residency Time-Constrained Single-Arm Cluster Tools

IEEE Trans. Semicond. Manufact.

Pan

et al. 2014

Self Cite

Cyclic scheduling and operation of a residency timeconstrained single-arm cluster tool with failure-prone process modules are highly challenging. In some cases, when a failure occurs, there still exists a feasible cyclic schedule for the performance-degraded tool. In other cases, such a schedule no longer exists. For the latter, it is highly desired to respond to a process module failure properly such that the tool can continue working and the wafers in the tool can be completed in a feasible way. This work is the first one to study this important issue. The idea is to apply Petri nets to describe the dynamic behavior of a single-arm cluster tool. With the developed Petri net model, this paper formulates failure response policies to control the cluster tool such that it can keep working without violating any residency time constraint. The failure response policies are implemented via efficient real-time control laws. Illustrative examples are presented to show their usage.

“…In order to effectively operate cluster tools, extensive studies on their modeling and performance evaluation have been done [11], [19]- [26], [28], [31], [32], [38], [39], [41]- [44], [47], [48]. They show that a cluster tool operates under a steady state for most of the time.…”

Section: Related Workmentioning

confidence: 99%

Optimal One-Wafer Cyclic Scheduling of Single-Arm Multicluster Tools With Two-Space Buffering Modules

Yang

IEEE Trans. Syst. Man Cybern, Syst.

et al. 2014

A multi-cluster tool is composed of a number of individual cluster tools linked by buffering modules (BMs). The capacity of a BM can be one or two. Aiming at finding an optimal one-wafer cyclic schedule, this paper explores the effect of twospace BMs on the performance of a multi-cluster tool. A Petri net (PN) model is developed to model it by extending resourceoriented PNs. The dynamic behavior of robot waiting and tasks, process modules, and buffers is well described by the model. This paper shows that there is always a one-wafer cyclic schedule that reaches the lower bound of the cycle time of a process-bound tool. Furthermore, a closed-form algorithm is revealed to find such a schedule for the first time for such multi-cluster tools. Illustrative examples are given to show the application and power of the proposed method.Index Terms-Multi-cluster tools, Petri net (PN), scheduling, semiconductor manufacturing.