Tool For Process Development Research Articles

Interferometric Real‐Time Measurement of Uniformity for Plasma Etching

A new technique has been developed to measure etch rate uniformity in situ using a charge coupled device (CCD) camera which views the wafer during plasma processing. The technique records the temporal modulation of plasma emission or laser illumination reflected from the wafer; this modulation is caused by interferometry as thin films are etched or deposited. The measured etching rates compared very well with those determined by helium‐neon laser interferometry. This technique is capable of measuring etch rates across 100 mm or larger wafers. It can resolve etch rate variations across a wafer or within a die. The CCD measurement technique is a valuable tool for process development and has potential use as a real‐time diagnostic for process control.

On The Role of Penetration Twins in The Morphological Development of Vapor-Grown Diamond Films

ABSTRACTBy control of deposition conditions, the morphologies of vapor-deposited polycrystalline diamond films may be varied deliberately from clean multi-micron crystallites to nanocrystalline ‘cauliflower’ nodules. Most attempts to connect diamond film ‘quality’ to growth conditions focus on competitive growth of non-diamond phases. In contrast, we propose that twinning is potentially the dominant factor. We develop a geometric parameterization of growth conditions to define conditions under which a common type of twin - the < 111> penetration twin - can outgrow and potentially bury the parent face on which it originated. We then show how the full range of CVD diamond crystal and film morphologies might be explained entirely in terms of penetration twins. This explanation does not entail reference to the actual mechanism of diamond growth. The geometric parameterization also suggests a ‘reactor map’ which serves as a powerful tool in process development and control.

119 E-LOT process development tool based on systematic quality analysis

119 E-LOT process development tool based on systematic quality analysis

E-LOT Process Development Tool Based on Systematic Quality Analysis

This paper presents some early results of a study for applying a new theory for managing contingencies in production lines. The E-LOT theory was developed in Harvard Business School in the late 80's. The aim of the research was to test the method in both synchronized and non-synchronized production lines in Finland. The test cases were selected from electronic, motor vehicle and paper industries. E-LOT methodology and later E-LOT control system could be a powerful tool to link quality management, production control and cost Optimization tasks in different processes. This presentation is produced mainly for academics studying production management and Optimization and managers responsible for production technology development, quality management and strategy development.

Spreading resistance:A quantitative tool for process control and development

During the last five years much work has been done in developing the spreading resistance technique. This work has led to a much clearer understanding of the strengths and weaknesses of the technique. It has been shown that it is capable of producing carrier concentration profiles which are accurate enough to be used in process control and development. A review is presented which highlights the three steps necessary to obtain such data. These are the optimization of the acquisition of raw data, the conversion of the raw data to carrier profiles, and finally the interpretation and use of the final profiles. A great emphasis is placed on the need to acquire the most accurate and reproducible data and on the methods which are used to achieve this objective. For the accurate profiling of ultrashallow layers such procedures are shown to be of paramount importance.

On-line capillary gas chromatography with automated liquid sampling, a powerful tool in biotechnology

A capillary gas chromatograph coupled to a bioprocess allows the on-line analysis of primary metabolites, e.g., acetoin, d/l- and meso-butane-2,3-diol and acetic acid, in liquid samples. The wide range of analytes, the excellent separation performance at high frequencies (<8 min per measurement) and the long operational stability ( > 5 days) render this technique a powerful tool for metabolic studies, process development and control.

On-line monitoring of furnace-wall corrosion in a 125 MW power generation boiler

A collaborative high-temperature corrosion-monitoring trial has been carried out by CAPCIS and the CEGB, using electrochemical monitoring instrumentation and ceramic-faced insert probes installed in a furnace wall on a 125 MW power generation boiler. The results showed that analysis of the electrochemical signals resulting from corrosion of the furnace wall, in the temperature range 300–1000 °C, can provide a good estimate of the corrosion rate. The applicability of the advanced on-line monitoring techniques for studying high temperature “dry” corrosion was demonstrated. The corrosion results, based on “typical” proportional factors, showed good agreement with corrosion rates previously measured by the CEGB using long-term single-coupon probes. The trial demonstrated that instrumentation and probes are now available to monitor high-temperature corrosion processes for improved control by on-line surveillance, or for use as a research investigation and process development tool.

Bioprocess Simulation: A New Tool for Process Development

Bioprocess Simulation: A New Tool for Process Development

An improved automatic test system for VLSI parametric testing

Automated and thorough characterization of MOS transistors has been made possible by using a minicomputer-based instrumentation system. A low-current circuit capable of forcing current levels down to the range of 10 pA has been designed on the personality board, allowing fast measurements of subthreshold characteristics. A comprehensive test program has been developed to extract device parameters, such as threshold voltage, subthreshold slope, intrinsic mobility, mobility degradation, effective-channel doping, body effect, ΔL, ΔW, series resistance, and carrier-saturation velocity. Data management software also provides detailed statistical analysis. The technique is found to be a powerful and essential tool for VLSI process development.

Thermodynamic availability analysis of fractional distillation with vapour compression

AbstractThermodynamic analysis based on the concept of availability or energy arising from the second law of thermodynamics is a useful tool for process development and design. The exergy is especially useful for analysing processes containing different forms and qualities of energy. In these cases the analysis based on the first law could not give meaningful results.The work attempts to show in what circumstances the compression of the overhead vapour from a distillation column and the use of condensing vapours to reboil the bottoms is preferred to the conventional scheme. To achieve this goal, the thermodynamic energy coefficient of performance of the system is calculated as a function of system properties, column pressure, degree of separation, compression ratio and number of plates. The results of calculations indicate the effect of each variable on the thermodynamic performance of distillation with vapour compression and point out directions for process improvement.

Progress of the dephosphorization of iron

Software for calculation of phase diagrams and thermodynamic properties have been developed since the 1970's. Software and computers have now developed to a level where such calculations can be used as tools for material and process development. In the present paper some of the latest software developments at Thermo-Calc Software are presented together with application examples. It is shown how advanced thermodynamic calculations have become more accessible since: &#x02022;—|A more user-friendly windows version of Thermo-Calc, TCW, has been developed.&#x02022;—|There is an increasing amount of thermodynamic databases for different materials available.&#x02022;—|Thermo-Calc can be accessed from user-written software through several different programming interfaces are available which enables access to the thermodynamic software from a user-written software. Accurate data for thermodynamic properties and phase equilibria can then easily be incorporated into software written in e.g. C++, Matlab and FORTRAN.Thermo-Calc Software also produces DICTRA, a software for simulation of diffusion controlled phase transformations. Using DICTRA it is possible to simulate processes such as homogenization, carburising, microsegregation and coarsening in multicomponent alloys. The different models in the DICTRA software are briefly presented in the present paper together with some application examples.