Liquid Etch of Moisture Resistant Polyimides

1992 ◽  
Vol 264 ◽  
Author(s):  
D. E. Fjare ◽  
A. J. Beuhler ◽  
C. A. Navar
Keyword(s):  
Amic Acid ◽  
Aliphatic Amines ◽  
Polyamic Acid ◽  
Base Component ◽  
Wet Etch ◽  
Moisture Resistant ◽  
Active Base

AbstractA new wet patterning technology which is particularly well suited to moisture resistant polyimides is described. The key feature is a two step wet-etch with the photoresist patterned and the amic acid etched in sequential steps. A higher degree of sidewall control than previously attained is possible because the etchant can be tailored specifically for the polyamic acid. The etchants operate by the polarity shift mechanism conventionally used to etch polyamic acids with hydroxide bases, but instead use the weaker aliphatic amines as the active base component. Alcohols are used to adjust the polarity of the solvent.

scholarly journals Room temperature synthesis of perylene diimides facilitated by high amic acid solubility

2022 ◽  
Author(s):  
Marcus C Kwakernaak ◽  
Marijn Koel ◽  
Peter J. L. van den Berg ◽  
E. M. Kelder ◽  
Wolter Jager
Keyword(s):  
Room Temperature ◽  
Amic Acid ◽  
Aliphatic Amines ◽  
Temperature Synthesis ◽  
Perylene Diimides ◽  
Room Temperature Synthesis ◽  
Acid Solubility

A novel protocol for the synthesis of perylene diimides (PDIs), by reacting perylene dianhydride (PDA) with aliphatic amines is reported. Full conversions were obtained at temperatures between 20 and 60˚C,...

Cure Studies of Fluorinated Polyamic Acids by Thermal-IR

1992 ◽  
Vol 264 ◽  
Author(s):  
Robert T. Roginski ◽  
Douglas E. Fjare
Keyword(s):  
Ir Spectroscopy ◽  
Phthalic Anhydride ◽  
Amic Acid ◽  
Back Reaction ◽  
Curing Process ◽  
Thermal Curing ◽  
Additional Mechanism ◽  
Polyamic Acid

AbstractThe thermal curing chemistry of a fluorinated polyamic acid based on 6FDA (hexafluoroisopropylidene bis(phthalic anhydride)) and APBP (4,4′-bis(4-aminophenoxy)biphenyl) was studied by thermal-IR spectroscopy. Anhydride formation was observed at intermediate cure temperatures and maximized at approximately 220°C. The degree of anhydride formation was affected by the solvent, being least in 2-methoxyethyl ether and increasing in the solvent order: 2-methoxyethyl ether < NMP < 2-(2-ethoxy)ethoxyethanol. In addition to the back reaction of amic acid to anhydride and amine, at least one additional mechanism of anhydride formation is observed. The onset of the second mechanism of anhydride formation is coincident with the onset of imidization, which leads us to propose that water generated by imidization can react with anhydride during the curing process, before escaping from the film, to form diacid. Cyclization of diacid to anhydride is proposed as the second mechanism of anhydride formation.

Synthesis and catalytic, antimicrobial and cytotoxicity evaluation of gold and silver nanoparticles using biodegradable, Π-conjugated polyamic acid

2015 ◽  
Vol 2 (5) ◽  
pp. 518-527 ◽  
Author(s):  
Victor M. Kariuki ◽  
Idris Yazgan ◽  
Ali Akgul ◽  
Andrzej Kowal ◽  
Magdalena Parlinska ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Silver Nanoparticles ◽  
Amic Acid ◽  
Simple Synthesis ◽  
Gold And Silver Nanoparticles ◽  
Polyamic Acid ◽  
Biodegradable Poly

We hereby report a rapid and simple synthesis of silver (AgNPs) and gold nanoparticles (AuNPs) using conductive, electroactive and biodegradable poly(amic)acid (PAA) polymer as both the reductant and stabilizer.

Exogenous Directing Group Free, Ligand-Enabled gamma-C(sp3)–H Arylation of Free Primary Aliphatic Amines and α-Amino Esters

2019 ◽  
Author(s):  
Yongzheng Ding ◽  
Shuai Fan ◽  
Xiaoxi Chen ◽  
yuzhen gao ◽  
Gang Li
Keyword(s):  
Amino Acids ◽  
Large Scale ◽  
Free Ligand ◽  
Aliphatic Amines ◽  
Rapid Synthesis ◽  
Amino Esters ◽  
Directing Group ◽  
Large Scale Synthesis ◽  
Primary Aliphatic Amines

A Pdᴵᴵ-catalyzed, ligand-enabled gamma-C(sp3)–H arylation of free primary aliphatic amines and amino esters without using an exogenous directing group is reported. This reaction is compatible with unhindered free aliphatic amines, and it is also be applicable to the rapid synthesis of biologically and synthetically valuable unnatural α-amino acids. Large scale synthesis is also feasible using this method.<br>

Application of KOH Electrochemical Etch and Passive Voltage Contrast Techniques for Deep Sub-Micron CMOS Leaky Gate Detection

2000 ◽  
Author(s):  
Fred Y. Chang ◽  
Victer Chan
Keyword(s):  
Case Studies ◽  
Detection Technique ◽  
Cobalt Silicide ◽  
Process Technology ◽  
Process Flow ◽  
Voltage Contrast ◽  
Emission Detection ◽  
Wet Etch ◽  
Direct Confirmation

Abstract This paper describes a novel de-process flow by combining cobalt silicide / nitride wet etch with KOH electrochemical wet etch (ECW) to identify leaky gate in silicided deep sub-micron process technology. Traditionally, leaky gate identification requires direct confirmation by gate level electrical or emission detection technique. Ohtani [1] used KOH electrochemical etch application to identify nonsilicided leaky gate capacitor in DRAM without using the above confirmation. The result of the case study demonstrates the expanded application of ECW etch to both silicided 0.18um logic and SRAM devices. Voltage contrast at metal 1 to assist leaky gate localization is also proposed. By combining both techniques, the possibility for isolating gate related defects are greatly enhanced. Case studies also show the advantages of the proposed technique over conventional poly level voltage contrast in leaky gate identification especially with devices that use local interconnect and nitride liner process.

A Review of Wet Etch Formulas for Silicon Semiconductor Failure Analysis

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.

Locating Gate Oxide Failures Using KOH

2016 ◽  
Author(s):  
Lori L. Sarnecki
Keyword(s):  
Potassium Hydroxide ◽  
Gate Oxide ◽  
New Technique ◽  
Deep Trench ◽  
New Methods ◽  
Wet Etch

Abstract This paper presents two new methods using potassium hydroxide (KOH) as a wet etch technique to successfully stop on gate oxide and find the submicron gate oxide failures that correspond to failure response sites. Applications of this new technique to submicron gate oxide failures on both planar and deep trench MOSFET devices are reported in this paper.

Deprocessing Methodologies for Detection of IBC and Cell-to-Cell Shorts in Submicron DRAM

2012 ◽  
Author(s):  
Ramachandra Chitakudige ◽  
Sarat Kumar Dash ◽  
A.M. Khan
Keyword(s):  
High Selectivity ◽  
Electron Cyclotron Resonance ◽  
Random Access ◽  
Random Access Memory ◽  
Access Memory ◽  
Plasma System ◽  
Poly Silicon ◽  
Hazardous Gases ◽  
Wet Etch ◽  
Resonance Plasma

Abstract Detection of both Insufficient Buried Contact (IBC) and cell-to-cell short defects is quite a challenging task for failure analysis in submicron Dynamic Random Access Memory (DRAM) devices. A combination of a well-controlled wet etch and high selectivity poly silicon etch is a key requirement in the deprocessing of DRAM for detection of these types of failures. High selectivity poly silicon etch methods have been reported using complicated system such as ECR (Electron Cyclotron Resonance) Plasma system. The fact that these systems use hazardous gases like Cl2, HBr, and SF6 motivates the search for safer alternative deprocessing chemistries. The present work describes high selectivity poly silicon etch using simple Reactive Ion Etch (RIE) plasma system using less hazardous gases such as CF4, O2 etc. A combination of controlled wet etch and high selectivity poly silicon etch have been used to detect both IBC and cell-to-cell shorts in submicron DRAMs.

Microporous Membranes from an Insoluble Polyimide

1995 ◽  
Vol 60 (10) ◽  
pp. 1741-1746
Author(s):  
Jan Schauer ◽  
Miroslav Marek
Keyword(s):  
Acetic Anhydride ◽  
Phase Inversion ◽  
Amic Acid ◽  
Microporous Membranes ◽  
Inversion Process ◽  
Phase Inversion Process ◽  
Ultrafiltration Process

Poly(amic acid) prepared from 3,3',4,4'-benzophenonetetracarboxylic dianhydride and bis(4-aminophenyl) ether was used for preparation of microporous membranes by the phase inversion process. Membranes coagulated in acetic anhydride were brittle but usable for ultrafiltration. Coagulation of the poly(amic acid) in water or lower alcohols and subsequent thermal cyclocondensation led to extremely brittle polyimides, which limits their use for ultrafiltration process.

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