Appendix - Graphical Data

A Review of Wet Etch Formulas for Silicon Semiconductor Failure Analysis

ISTFA 1996: Conference Proceedings from the 22nd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa1996p0319 ◽

1996 ◽

Author(s):

T.W. Lee

Keyword(s):

Failure Analysis ◽

Literature Search ◽

Wet Etching ◽

Second Step ◽

Environmental Concerns ◽

Acid System ◽

Graphical Data ◽

Selective Etch ◽

Chromium Compounds ◽

Wet Etch

Abstract WET ETCHING is an important part of the failure analysis of semiconductor devices. Analysis requires etches for the removal, delineation by decoration or differential etching, and study of defects in layers of various materials. Each lab usually has a collection of favored etch recipes. Some of these etches are available premixed from the fab chemical supply. Some of these etches may be unique, or even proprietary, to your company. Additionally, the lab etch recipe list will usually contain a variety of classical "named etches". These recipes, such as Dash Etch, have persisted over time. Although well-reported in the literature, lab lists may not accurately represent these recipes, or contain complete and accurate instructions for their use. Time seems to have erased the understanding of the purpose of additives such as iodine, in some of these formulas. To identify the best etches and techniques for a failure analysis operations, a targeted literature review of articles and patents was undertaken. It was a surprise to find that much of the work was quite old, and originally done with germanium. Later some of these etches were modified for silicon. Much of this work is still applicable today. Two main etch types were found. One is concerned with the thinning and chemical polishing of silicon. The other type is concerned with identifying defects in silicon. Many of the named etches were found to consist of variations in a specific acid system. The acid system has been well characterized with ternary diagrams and 3-D surfaces. The named etches were plotted on this diagram. The original formulas and applications of the named etches were traced to assure accuracy, so that the results claimed by the original authors, may be reproduced in today's lab. The purpose of this paper is to share the condensed information obtained during this literature search. Graphical data has been corrected for modem dimensions. Selectivities have been located and discussed. The contents of more than 25 named etches were spreadsheeted. It was concluded that the best approach to delineation is a two-step etch, using uncomplicated and well-characterized standard formulas. The first step uses a decoration or differential etch technique to define the junctions. Formulations for effective decoration etches were found to be surprisingly simple. The second step uses a selective etch to define the various interconnections and dielectric layers. Chromium compounds can be completely eliminated from these formulas, to meet environmental concerns. This work, originally consisting of 30 pages with 106 references, has been condensed to conform with the formatting requirements of this publication.

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Crossbreed impact of double-diffusivity convection on peristaltic pumping of magneto Sisko nanofluids in non-uniform inclined channel: A bio-nanoengineering model

Science Progress ◽

10.1177/00368504211033677 ◽

2021 ◽

Vol 104 (3) ◽

pp. 003685042110336

Author(s):

Safia Akram ◽

Maria Athar ◽

Khalid Saeed ◽

Alia Razia

Keyword(s):

Mathematical Modeling ◽

Magnetic Field ◽

Physical Parameters ◽

Induced Magnetic Field ◽

Long Wavelength ◽

Inclined Channel ◽

Graphical Data ◽

Peristaltic Pumping ◽

Highly Nonlinear ◽

Linear Pdes

The consequences of double-diffusivity convection on the peristaltic transport of Sisko nanofluids in the non-uniform inclined channel and induced magnetic field are discussed in this article. The mathematical modeling of Sisko nanofluids with induced magnetic field and double-diffusivity convection is given. To simplify PDEs that are highly nonlinear in nature, the low but finite Reynolds number, and long wavelength estimation are used. The Numerical solution is calculated for the non-linear PDEs. The exact solution of concentration, temperature and nanoparticle are obtained. The effect of various physical parameters of flow quantities is shown in numerical and graphical data. The outcomes show that as the thermophoresis and Dufour parameters are raised, the profiles of temperature, concentration, and nanoparticle fraction all significantly increase.

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