Showing papers on "Process modeling published in 1985"

A programming process architecture

Abstract: The Programming Process Architecture is a framework describing required activities for an operational process that can be used to develop system or application software. The architecture includes process management tasks, mechanisms for analysis and development of the process, and product quality reviews duringt he various stages of the development cycle. It requires explicit entry criteria, validation, and exit criteria for each task in the process, which combined form the "essence" of the architecture. The architecture describes requirements for a process needing no new invention, but rather using the best proven methodologies, techniques, and tools available today. This paper describes the Programming Process Architecture and its use, emphasizing the reasons for its development.

COMPOSITE -- A Complete Modeling Program of Silicon Technology

Abstract: A new two-dimensional process modeling program written in Fortran is described. For the first time, this program allows the simulation of all important processing steps occurring in typical sequences involved in the fabrication of integrated circuits such as doping, oxidation, lithography, etching, and layer deposition. The program possesses a modular structure to allow for easy changing and improvement of process models as well as of mathematical procedures. The program is menu driven to make it easy to use for non-experts and it is readily usable with different computer systems.

SIMPL-2 (SIMulated Profiles from the Layout-Version 2)

Abstract: SIMPL is a computer-aided-design (CAD) tool for simulating the cross-sectional profile of integrated circuits along an arbitrary cut-line drawn on the layout. The linked-list arbitrary polygonal data structure, process specification file, physical process algorithms, graphics display interface, and linking to external rigorous process simulators of SIMPL-2 are described. SIMPL-2 is capable of displaying in color two-dimensional process effects such as the bird's-beak, lateral diffusion, undercut in etching, and sidewall coverage in deposition, based on its linked-polygonal and grid-type databases. The device profile from the composite can be generated rapidly in several minutes on a VAX 11/780 using elementary internal physical process models. SIMPL-2 can also invoke more rigorous external process simulators through an interface for profile data and transfer of control, providing a heretofore missing link between layout-based CAD tools and process and device simulators. >

Advanced bipolar transistor modeling: process and device simulation tools for today's technology

Abstract: A series of programs have been developed and linked together for doing advanced transistor modeling. The strategy begins with a process modeling program, SAFEPRO, for predicting two-dimensional impurity profiles. These are input to a two-dimensional device physics modeling program, 2DP, for generating device electrical characteristics. A three-dimensional distributed device model is then assembled by a model generator program (MGP) which, in turn, is used to derive a lumped equivalent-circuit model for numerical circuit analysis. The tools make it possible to do process sensitivity studies, perform process and device optimization, and provide early feedback on technology performance. The approach has recently been used to examine and compare various technologies at IBM.

Chapter 7 Environmental economics, industrial process models, and regional-residuals management models

Abstract: Publisher Summary Sufficient experience has now been gained in the industrial process/REQM area for a number of conclusions to be drawn, and for various challenges to be identified in future research. The most important fact to emerge is that if requirements management (REQM) modeling is to have practical relevance—in terms of analyzing alternative industrial process technologies, assessing their effects on ambient environmental quality, and indicating guidelines for environmental managers to follow economists need access to detailed physical and engineering models and data. The chapter reviews that the relationship between modelers and users is crucial. Modelers must realize that the object of analysis is not the construction of theoretically elaborate mathematical systems, but the solution of specific problems. For future research on industrial activities, physical measures of inputs, commodity outputs and residuals discharges associated with specific process technologies are clearly superior to monetary measures. Compilations of commonly used industrial technologies and residuals modification processes are extremely useful to REQM modelers. Nonreactive dispersion modeling appears to have reached a satisfactory stage of development, especially for steady-state calculations. Finally, the chapter concludes that mathematical programming and simple tradeoff models can make important contributions. When more experience in environmental systems modeling has been gained, full benefit-cost analyses of regional industrial development programs and environmental quality management may evolve.

COMPOSITE—A complete modeling program of silicon technology

Abstract: A new two-dimensional process modeling program written in Fortran is described. For the first time, this program allows the simulation of all important processing steps occuring in typical sequences involved in the fabrication of integrated circuits such as doping, oxidation, lithography, etching, and layer deposition. The program possesses a modular structure to allow for easy changing and improvement of process models as well as of mathematical procedures. The program is menu driven to make it easy to use for non-experts and it is readily usable with different computer systems.

Process modelling and industrial energy use in developing countries—The steel industry in India

Abstract: A process model is used to study energy use and conservation in the steel industry in India. Production is modelled by a set of inter-connected process activities, each of which defines unique relationships between process output and a number of inputs. Contrary to that in process models for the U.S., we do not assume cost minimizing behavior. Simulation results show that although a number of cost-effective energy conservation measures exist, none of them would lead to significant reductions in energy use. Effective policy for the Indian Steel industry would require combining the strategies.

Behavior: A Temporal Approach to Process Modelling

Abstract: This paper describes an approach to modeling processes and networks of processes that communicate exclusively through message passing. A process is defined by its set of possible behaviors, where each behavior is an abstraction of some infinite execution sequence of the process. The resulting model of processes is simple and modular and facilitates information hiding. It can describe either synchronous or asynchronous networks. It supports recursively-defined networks and can characterize liveness properties such as progress of inputs and outputs, termination and deadlock. A sound and complete temporal proof system for processes is presented. It is compositional — a specification of a network is formed naturally from specifications of its component processes. A nontrivial example, comprising a specification and correctness proof for a recursive network, is given to demonstrate the usefulness of our techniques.

Using Process Models with Expert Systems to Aid Process Control Operators

Abstract: Expert systems technology seems to have great promise as a medium through which the expertise of master process control operators may be made available as a tool for the average operator However, fulfillment of this promise will depend upon the extent to which expert systems can be of immediate use to operators in the performance of their critical job duties, and provide them with help that is not more readily available through other approaches In this paper, we describe how expert systems might be applied to the process control operator's various duties, in order to identify the technical advances needed for the full potential of expert systems technology to be realized Next, we describe how process models of various types may be used in conjunction with expert systems in order to meet some of these needs, and advance the state-of-the-art in the applications of expert systems to process control Finally, we list several criteria for choosing near-term expert systems development projects, in light of these considerations

Numerical conformal mapping for treatment of geometry problems in process simulation

Abstract: In semiconductor modeling, partial differential equations often have to be solved on a domain with a curved boundary. A numerical conformal mapping well suited for process modeling problems is presented. Its use in connection with a moving boundary is explained.

Numerical Conformal Mapping for Treatment of Geometry Problems in Process Simulation

Abstract: In semiconductor modeling, partial differential equations often have to be solved on a domain with a curved boundary. A numerical conformal mapping well suited for process modeling problems is presented. Its use in connection with a moving boundary is explained.

Approximate Model Identification via Set-Theoretic Estimation

Abstract: The performance achievable with a model-based process control strategy increases with the fidelity of the model used, but so do the cost and complexity of these models. This trade-off has led Prater to propose the "principle of optimum sloppiness"--make the model only as detailed as necessary to minimize cost and complexity. But model accuracy is difficult to quantify a priori, especially for simplified models of complex processes. This paper considers the "parameter uncertainty intervals" described by Milanese and Belforte as a method of determining model uncertainty and develops a simple recursive algorithm for evaluating these parameter bounds. A numerical example is included to illustrate the utility of the method, and its application to the problem of approximate process modeling is discussed.