Jin-Hwan Lee

SECAM: a supervisory equipment control application model for integrated semiconductor manufacturing equipment

This paper describes SECAM (Supervisory Equipment Control Application Model), an object-oriented application prototype for SECs (supervisory equipment controller) for integrated semiconductor manufacturing equipment based on a high-level fieldbus PROFIBUS-FMS. It also features a layered architecture based on some key objects including service objects (SOs), command objects, and virtual control device (VCD) objects, which facilitate complex supervisory control application design and implementation based on highlevel fieldbus services. The proposed approach is demonstrated for a CTC for semiconductor manufacturing.

Cluster tool module communication based on a high-level fieldbus

A cluster tool for semiconductor manufacturing is an integrated device that consists of several single wafer processing modules and a wafer transport module based on a robot. The distributed module controllers are integrated by an inter-module communication network and are coordinated by a centralized controller, called a cluster tool controller (CTC). Since the CTC monitors and coordinates the distributed complex module controllers for advanced process control, complex communication messaging and services between the CTC and the module controllers are required. A SEMI standard, CTMC (cluster tool module communication), specifies application-level communication service requirements for inter-module communication. We propose the use of high-level fieldbuses–for instance, PROFIBUS-FMS–for implementing CTMC since the high-level fieldbuses are well suited for complex real-time distributed manufacturing control applications. We present a way of implementing CTMC using PROFIBUS-FMS as the communication enabler. We first propose improvements of a key object of CTMC for material transfer and the part transfer protocol to meet the functional requirements of modern advanced cluster tools. We also discuss mapping objects and services of CTMC to PROFIBUS-FMS communication objects and services. Finally, we explain how to implement the mappings.

A two-phase approach for design of supervisory controllers for robot cells: model checking and Markov decision models

The supervisory controller for a robot cell is specified as a dynamic control policy that determines the part processing sequence and the robot work cycle depending on the state of the cell. The supervisory controller should be designed not only to satisfy the prescribed logical requirements or constraints, but also to achieve the maximum operating efficiency. We discuss modeling and control issues for robot task planning. We propose a two-phase approach to design the supervisory controller that consists of the logical design phase and the performance design phase. In the first phase, we use a model checking technique for concurrent automata to verify whether the proposed logical control rules satisfy the logical requirements. The logical control requirements may include deadlock prevention, obedience to the technological operation sequence of each part, or prevention of wasteful robot moves. In the second phase, we use semi-Markov decision models to determine additional control decisions for which the robot cell has the maximum throughput rate. We discuss the structure and algorithms of the performance control design problem.

An integrated application framework for a cluster tool controller for semiconductor manufacturing

A cluster tool integrates several processing modules with a wafer handling module. Cluster tools are essential for semiconductor manufacturing automation. A CTC (cluster tool controller) is a complex distributed control application that monitors and coordinates the component modules and is also monitored and commanded by the MES (Manufacturing Execution System). Recently, SEMI (Semiconductor Equipment and Materials International) released two important CIM standards, CTMC (Cluster Tool Module Communication) and OBEM (Object-Based Equipment Model). CTMC defines high-level messaging and application-level communication service standards between a CTC and the module controllers, which are based on an object-oriented model of the CTC communication functions. OBEM specifies high-level application object models for equipment with which the objects of an MES application based CIM Framework Standard, a SEMI standard for an object-oriented MES application framework, communicate through distributed object invocation. We discuss issues and strategies for integrating the two object-oriented communication interface standards, CTMC and OBEM, into an object-oriented CTC application framework.