Narrow Range Ethoxylates - Highly targeted performance for more effective cle...Sorel Muresan
A narrow range ethoxylated alcohol, also called “a peaked ethoxylate”, has a distribution curve that is narrower than the equivalent standard alcohol ethoxylate with a considerably lower content of unreacted alcohol and lower foam than standard ethoxylates. Narrow range ethoxylates have targeted properties to improve degreasing performance at lower use concentration, while eliminating the need for hazardous solvents. At the same time they are compatible with most commonly used surfactants and builders. They also have very low odor, even if based on a short chain alcohol. This opens up many applications where short chain alcohol ethoxylates have previously been excluded and enables the formulator to prepare highly effective low VOC cleaners. The lower free alcohol content and higher proportion of the target ethoxylate make formulating easier and more cost effective than with standard alcohol ethoxylates. This offers the possibility to optimize raw material purchase, reduce inventories, and simplify production.
Acidity of phenol|Organic Chemistry-Acidity Of Phenols(Explained in Detail)Anjali Bhardwaj
Why Phenols are more acidic than alcohols(Detail Explanation)
-Resonance structure of Phenoxide ion
This video is useful for B.Pharmacy 3rd Semester students
Pharmaceutical Organic Chemistry -2|B.Pharmacy|IIT-JEE|NEET
As per PCI Syllabus
Narrow Range Ethoxylates - Highly targeted performance for more effective cle...Sorel Muresan
A narrow range ethoxylated alcohol, also called “a peaked ethoxylate”, has a distribution curve that is narrower than the equivalent standard alcohol ethoxylate with a considerably lower content of unreacted alcohol and lower foam than standard ethoxylates. Narrow range ethoxylates have targeted properties to improve degreasing performance at lower use concentration, while eliminating the need for hazardous solvents. At the same time they are compatible with most commonly used surfactants and builders. They also have very low odor, even if based on a short chain alcohol. This opens up many applications where short chain alcohol ethoxylates have previously been excluded and enables the formulator to prepare highly effective low VOC cleaners. The lower free alcohol content and higher proportion of the target ethoxylate make formulating easier and more cost effective than with standard alcohol ethoxylates. This offers the possibility to optimize raw material purchase, reduce inventories, and simplify production.
Acidity of phenol|Organic Chemistry-Acidity Of Phenols(Explained in Detail)Anjali Bhardwaj
Why Phenols are more acidic than alcohols(Detail Explanation)
-Resonance structure of Phenoxide ion
This video is useful for B.Pharmacy 3rd Semester students
Pharmaceutical Organic Chemistry -2|B.Pharmacy|IIT-JEE|NEET
As per PCI Syllabus
this is the simple ppt about the manufacturing of H-acid which is used as the dye and dye intermediate in industry, and it is part of the syllabus in GTU sem-IV in subject of CPI-II.
It low molecular wt. raw polymeric materials
It is used for binders, curable molding compositions adhesives and coatings.
They normally have a melting or softening range, are brittle in the solid state.
Resins : natural resins and synthetic resins.
Synthetic resins:
phenol-formaldehyde resins*, urea-formaldehyde,
melamine-formaldehyde resins, polyesters resins,
silicone resins, epoxy resins, acrylic resins and alkyd resins.
Installation of S-50 ammonia synthesis converter along with waste heat boiler in downstream of existing S-200 ammonia synthesis converter is one of the major schemes of Energy Saving Project of Ammonia plant. The energy saving reported 0.18 G.Cal/T of Ammonia. Several ammonia plants have installed an additional ammonia synthesis converter in combination with a HP steam waste heat boiler, downstream of the existing ammonia converter. The result is increased conversion per pass, reduced compression requirements due to the smaller recycle gas stream, and improved waste heat recovery. Among the methodologies aimed at finding energy saving opportunities, pinch analysis linked to power and steam modeling has proved to be a powerful way for determining projects to improve the overall energy efficiency of industrial sites. This procedure has been applied successfully in many industrial facilities, allowing optimal energy recovery in the process and hence reduction of fuel consumption.
How to Manufacture Synthetic Resins (Actel Resins, Amino Resins, Casein Resin...Ajjay Kumar Gupta
Synthetic resin is typically manufactured using a chemical polymerization process. This process then results in the creation of polymers that are more stable and homogeneous than naturally occurring resin. Since they are more stable and are cheaper, various forms of synthetic resin are used in a variety of products such as plastics, paints, varnishes, and textiles. There are various kinds of synthetic resins; acetal resins, amino resins, casein resins, epoxy resins, emulsion polymers, hydrocarbon resins, polyamide resins, polyesters rubber resins etc. The classic variety is epoxy resin, manufactured through polymerization, used as a thermoset polymer for adhesives and composites.
Tags
Alkyl and hydroxy alkyl alkylcellulose, Applications of Synthetic Resins, Best small and cottage scale industries, Business Plan for a Startup Business, Business start-up, Emulsion polymers manufacture, Formulation of Synthetic Resins, Formulation of Resins, How to Manufacture Synthetic Resins, How to start a successful synthetic resin business, How to start a synthetic resin production Business, How to start a synthetic resin production?, How to Start Emulsions of Synthetic Resin Business, How to start synthetic resin production Industry in India, Indene-coumarone resins, Manufacturing process of Acrylonitrile Resins, Manufacturing process of Actel Resins, Manufacturing process of Alkyd Resin, Manufacturing process of Amino Resins, Manufacturing process of Casein Resins, Manufacturing process of Epoxy Resins, Manufacturing process of Ion-exchange Resins, Manufacturing process of Phenolic resins, Manufacturing process of Polyamide Resins, Manufacturing process of Polycarbonates Resins, Manufacturing process of Polyesters, Manufacturing process of Polyurethane resins, Manufacturing process of Polyvinyl Acetate Solid Resins, Manufacturing process of Silicone resins, Modern small and cottage scale industries, Most Profitable Synthetic resin Business Ideas, New small scale ideas in synthetic resin production industry, Process of making synthetic resin adhesive, Processing of synthetic resin, Production of a synthetic resin, Profitable Small Scale synthetic resin Manufacturing, Project for startups, Resin Types and Production, Rosin & rosin derivatives, Rubber resins Formulation, Setting up and opening your synthetic resin Business, Shellac resins, Small scale Commercial synthetic resin making, Small Scale Synthetic resin manufacturing Projects, Small scale synthetic resin production line, Small Start-up Business Project, Start Up India, Stand up India, Starting a synthetic resin production Business, Start-up Business Plan for synthetic resin production, Startup ideas, Startup Project, Startup Project for synthetic resin production, Startup project plan, Sucrose resins, Synthetic resin Based Profitable Projects, Synthetic resin Based Small Scale Industries Projects, Synthetic Resin Business,
Carbonated Softdrinks and ECA technology (CIP)Radical Waters
In the multi-billion dollar beverage industry, it is crucial that manufacturers produce consistent quality. Limited returns allow for sustained enhancement of brand image and equity. Food and beverage processing relies on water as its main ingredient and water quality needs to be of the highest possible standard. Under typical conditions, process or ingredient water is filtered repeatedly before use. While this procedure is effective, other sources of microbial contamination do exist. If left unchecked, these will likely result in product contamination and spoilage.
this is the simple ppt about the manufacturing of H-acid which is used as the dye and dye intermediate in industry, and it is part of the syllabus in GTU sem-IV in subject of CPI-II.
It low molecular wt. raw polymeric materials
It is used for binders, curable molding compositions adhesives and coatings.
They normally have a melting or softening range, are brittle in the solid state.
Resins : natural resins and synthetic resins.
Synthetic resins:
phenol-formaldehyde resins*, urea-formaldehyde,
melamine-formaldehyde resins, polyesters resins,
silicone resins, epoxy resins, acrylic resins and alkyd resins.
Installation of S-50 ammonia synthesis converter along with waste heat boiler in downstream of existing S-200 ammonia synthesis converter is one of the major schemes of Energy Saving Project of Ammonia plant. The energy saving reported 0.18 G.Cal/T of Ammonia. Several ammonia plants have installed an additional ammonia synthesis converter in combination with a HP steam waste heat boiler, downstream of the existing ammonia converter. The result is increased conversion per pass, reduced compression requirements due to the smaller recycle gas stream, and improved waste heat recovery. Among the methodologies aimed at finding energy saving opportunities, pinch analysis linked to power and steam modeling has proved to be a powerful way for determining projects to improve the overall energy efficiency of industrial sites. This procedure has been applied successfully in many industrial facilities, allowing optimal energy recovery in the process and hence reduction of fuel consumption.
How to Manufacture Synthetic Resins (Actel Resins, Amino Resins, Casein Resin...Ajjay Kumar Gupta
Synthetic resin is typically manufactured using a chemical polymerization process. This process then results in the creation of polymers that are more stable and homogeneous than naturally occurring resin. Since they are more stable and are cheaper, various forms of synthetic resin are used in a variety of products such as plastics, paints, varnishes, and textiles. There are various kinds of synthetic resins; acetal resins, amino resins, casein resins, epoxy resins, emulsion polymers, hydrocarbon resins, polyamide resins, polyesters rubber resins etc. The classic variety is epoxy resin, manufactured through polymerization, used as a thermoset polymer for adhesives and composites.
Tags
Alkyl and hydroxy alkyl alkylcellulose, Applications of Synthetic Resins, Best small and cottage scale industries, Business Plan for a Startup Business, Business start-up, Emulsion polymers manufacture, Formulation of Synthetic Resins, Formulation of Resins, How to Manufacture Synthetic Resins, How to start a successful synthetic resin business, How to start a synthetic resin production Business, How to start a synthetic resin production?, How to Start Emulsions of Synthetic Resin Business, How to start synthetic resin production Industry in India, Indene-coumarone resins, Manufacturing process of Acrylonitrile Resins, Manufacturing process of Actel Resins, Manufacturing process of Alkyd Resin, Manufacturing process of Amino Resins, Manufacturing process of Casein Resins, Manufacturing process of Epoxy Resins, Manufacturing process of Ion-exchange Resins, Manufacturing process of Phenolic resins, Manufacturing process of Polyamide Resins, Manufacturing process of Polycarbonates Resins, Manufacturing process of Polyesters, Manufacturing process of Polyurethane resins, Manufacturing process of Polyvinyl Acetate Solid Resins, Manufacturing process of Silicone resins, Modern small and cottage scale industries, Most Profitable Synthetic resin Business Ideas, New small scale ideas in synthetic resin production industry, Process of making synthetic resin adhesive, Processing of synthetic resin, Production of a synthetic resin, Profitable Small Scale synthetic resin Manufacturing, Project for startups, Resin Types and Production, Rosin & rosin derivatives, Rubber resins Formulation, Setting up and opening your synthetic resin Business, Shellac resins, Small scale Commercial synthetic resin making, Small Scale Synthetic resin manufacturing Projects, Small scale synthetic resin production line, Small Start-up Business Project, Start Up India, Stand up India, Starting a synthetic resin production Business, Start-up Business Plan for synthetic resin production, Startup ideas, Startup Project, Startup Project for synthetic resin production, Startup project plan, Sucrose resins, Synthetic resin Based Profitable Projects, Synthetic resin Based Small Scale Industries Projects, Synthetic Resin Business,
Carbonated Softdrinks and ECA technology (CIP)Radical Waters
In the multi-billion dollar beverage industry, it is crucial that manufacturers produce consistent quality. Limited returns allow for sustained enhancement of brand image and equity. Food and beverage processing relies on water as its main ingredient and water quality needs to be of the highest possible standard. Under typical conditions, process or ingredient water is filtered repeatedly before use. While this procedure is effective, other sources of microbial contamination do exist. If left unchecked, these will likely result in product contamination and spoilage.
[Case study] Jacksonville Electric Authority: Implementing a complete enterpr...Schneider Electric
Established in 1865, Jacksonville Electric Authority (JEA) is a public utility owned
by the City of Jacksonville, Florida. The JEA electric system currently serves
more than 417,000 electric customers in Jacksonville and parts of three adjacent
counties.
JEA owns and operates an electric system with three generating plants and
a fourth in the planning stages, and all transmission and distribution facilities
including approximately 730 miles of transmission lines and 6,000 miles of
distribution lines.
Ponencia realizada por Alejandro Marijanac de BLG en Transmodal 2011, 4º Foro de Logística Ïntermodal organizado por la Cámara de Álava y el Puerto de Bilbao. BLG nos muest
From the perspective of Bangladesh we have known that the Sneaker cleaner, snicker cleaners or the converse cleaners are not available from other company, Chemtrek is the first as a company that is introducing the snicker cleaner for our target market. That’s why we are not going to face any kind of direct competition from the market. But we have some indirect competitors in the market regarding snicker cleaning. In our country we have detergent or soup for cleaning these items. So indirectly we have to handle those competitors and establish a new product for snickers cleaning. So we are now trying to get a competitive path for our product to be established. We have known previously that there is no any direct competition for this particular product that is snicker cleaner, so we have the opportunity to take a significant place for our product. If we can synchronize our all of the proposed IMC plan, then. When we are saying about the snicker or converse then it is saying itself about its target market. Now a day’s snickers or converse are used by the young generation. Mainly we have targeted the students of the colleges and universities as our target customers.
In this plan we will try to cover all the communication tools for marketing or promoting the particular product “Kelly’s Sneaker Cleaner”.
Presentation given by George Romanos of the National Center for Scientific Research “Demokritos” (NCSRD), Greece, on "Novel IOnic LIquid and supported ionic liquid solvents for reversible CAPture of CO2- IOLICAP" at the EC FP7 Projects: Leading the way in CCS implementation event, London, 14-15 April 2014
Investigation on the Effect of TiO2 and H2O2 for the Treatment of Inorganic C...inventy
Sodium hypochlorite (NaClO) is regularly used as a disinfectant or a bleaching agent because of its high efficiency against many bacteria and viruses present in seawater along with its cheaper cost. Now a days, with the increase in the environmental concerns concerning the use of chlorination for the disinfection or bleaching of treated water related to the formation of potentially harmful chloro-organic by products through reactions with natural organic matter (NOM), it is preferred to implement a process with environmentally friendly chemicals for water treatment processes. About This report aim to study the possibility of reducing the inorganic carbon present in seawater by oxidization reaction of seawater with TiO2 and H2O2. Investigated and a comparison between thin film method and suspension method with a reactor system in conjunction with a light concentrating system has been done.
Influence of Ion Beam and Carbon Black Filler Type on the Mechanical and Phys...Editor IJCATR
Five types of carbon black nanofillers, namely Intermediate Super-Abrasion Furnace ISAF (N220), High-Abrasion Furnace
HAF-LS (N326), Fast Extruding Furnace FEF (N550), General Purpose Furnace GPF (N660) and Semi-Reinforcing Furnace SRF-HS
(N774) were incorporated with butadiene acrylonitrile rubber (NBR) in order to improve its physical properties. Young's modulus was
found to increase with nanofiller content. Percolation concentration was detected in mechanical as well as in Physico-chemical behavior.
The experimental values of the normalized Young's modulus fit well with Pukanszky et al. model; taking into consideration the difference
in carbon black-filler type. It is noticed that the characteristic time of swelling in toluene, τ is higher for NBR loaded with 30 phr ISAF
and for the rest of samples it increases with increasing of particle size. Finally oxygen ion beam irradiation for percolative loading NBR
nanocomposites increases Young's modulus nearly by 2-3 times.
1. I ~ _ _ l_~ _
A PROVEN SUB-MICRON PHOTORESIST STRIPPER SOLUTION
FOR POST METAL AND VIA HOLE PROCESSES
by
WaiMunLee
Vice President, Research & Development
EKC Technology, Inc.
Hayward, California, U.S.A.
ABSTRACT
A wet chemistry process based on hydroxylamine (HDATM)* chemistry has been found to remove
positive photoresist, sidewall polymers and other plasma process residues. The development of new chip
metallization materials, multimetal, and multilevel interconnect schemes for sub-micron processes have
placed new demands on wafer cleaning technology'. The high density connections of ULSI devices
require low resistance contacts2 •3 which in tum require extreme via hole cleanliness. The industry has
turned to combinations of wet and plasma photoresist stripping processes to achieve acceptably clean
,surfaces. Unfortunately, a result of plasma etching is the presence of' 'sidewall polymers" in the via holes
and other etching residues. SEM and surface contact angle evaluations indicate a HDA based solution
leaves surfaces free of resist and etching visual contamination. HDA processes exhibit lower levels of
mobile ionic contamination, as indicated by eN shifts, VT shifts and TOF-SIMS measurements.
'Product EKC265™ from EKC Technology, Inc.,
A ChE!mFirst Company, U.S. Patents 20 •
Other U.S. and Foreign Patents Pending.
>
~EKC Technolo~ Inc.
Additional prints available from:
EKe Technology, Inc.
A ChernFirsl Company
2520 Barrington Court, Hayward, CA 94545
ph: ~'1 510-784-9105 facs: +1 510-784-9181
2. INTRODUCTION
The work reported in this paper is based on evaluations perfonned in the EKC Technology Inc.,
Research and Development Laboratory and from an EKC sponsored study at Edinburgh
University, Scotland (Ref. #24). This paper is published in the pirOceedings of the Symposium on
Interconne.cl:s, Contact Metallization and Multilevel Metallization, Volume 93-25 of The
Electrochemical Society, Inc.
REVIEW OF RESIST STRIPPING CHElVtISTRY
A conventional positive photoresist consists of three components: a Novalak resin (a condensation
reacted product of cresol and formaldehyde - Figure 1), a photo active compound (a substituted
Napthoquinone Diazide - Figure 2) and a solvent (usually a mixture of glycol ethers)4,5,6.
x
Figure 1: Novalak Resin Figure 2: Substituted Di'azide
The stripping of organic photoresists occurs by oxidation, dissolution, or reduction mechanisms.
The mechanisms for the most popular resist stripping methods are shown in Table 1.
TABLE I' PHOTORESIST STRIPPING MECHANISMS
Dry Process Wet Process Mechanism
02 Plasma H202 IH 2S04
(NH4hS20sIH2S04 Oxidation
Fuming Nitric Acid
Solvent Stripper Dissolution
Ih Plasma Reduction
~i Page "2Jh;-19-9-6-EK-C-"j;-e-ch-n-OIO-9-y,-ln-C-'- - - - - - - - - - - - - - - - - - - - - - - - - - -
3. Oxidation The use of an oxidizer, such as hydrogen peroxide or ammonium persulfate in
concentrated sulfuric acid, for photoresist removal and wafer cleaning processes has been widely
reported?,8.9. A wafer cleaning process using hydrogen peroxide and ammonium hydroxide is
commonly referred to as the RCA clean 10. Fuming nitric acid has also been used extensively asa
cleaning and stripping agent, especially in Europe and Japan. Each of these solutions act on the
photoresist through an oxidation mechanism.
Oxygen plasma resist removal processes (also called dry stripping or ashing) carne into wide use
dUring the 1980's to remove the hardened resists created during p.asma etching processes. Plasma
systems have a variety of designs as discussed by Skidmore 11. They are downstream, parallel
plate12, UV/Ozone, etc. In the system the plasma field oxidizes (Equation #1) the resist molecules
(containing carbon, nitrogen, sulfur, hydrogen, and oxygen) into volatile gasses (carbon dioxide,
nitrogen dioxide, sulfur dioxide, and water) which are removed from the system by vacuum.
[1}
Dissolution
While wet strippers based on oxidation mechanisms are the most frequently used for chemical
stripping, they are limited to wafer steps where no metals are present. The acid based strippers
attack the metallization materials. At the steps with metal on the wafer the preferred wet stripper
for positive resists is a solvent/amine type. A solvent/amine stripper removes resist by a process
of penetration, swelling, and dissolutionS. The solvent molecules solvate the polymer molecule
and overcome the attractive forces that hold the polymer together. This mechanism is optimized
in a number of proprietary stripper solutions that mix various aprotic solvents (N-rnethyl-2-
pyrrolidone [NMP], dimethyl sulfoxide [DMSO], sulfolane, dimethylformamide [DMF], or
dimethylacetamide [DMAC]) with different organic amines. Table #2 summarizes a number of
commercially available, patented positive photoresist strippers.
TABLE 2' PHOTORESIST STRIPPER PATENT SURVEY
Solvent Amine Patent No. Assigned to
1 NMP Aminoethyl JK 60-131535 Allied Chemical
Piperadine
2 'NMP I _
JK 61-6827 Shipley
3 NMP/Sulfolane Isopropyl amine JK 63-186243 J. T. Baker
DMF/Sulfolane EP 102628
4 NMP Amine US 4617251 Olin Hunt
5 NMP Hydroxyl ethyl WO 8705314 Mac Dermid
Morpholine
6 DMSO I Amino alcohol JK 64-81950 Asahi Chern.
7 LPMSOIBLO Amino alcohol JK 64-42653 Tokyo Ohka
8 NMPIDMF Diethylenetriamine US 4824763 EKC Technology
9 DMAC Diethanolamine US 4770713 ACT
10 DMAC··others Amine JK 63-231343 Hitachi
11 DMF Amino alcohol JK 64-81949 Asahi Kasei
12 NMP or DMF Ammonium Salt JK 61-292641 Hoechst Japan
--------------------------1. Page 3 tr
5. Etch Residue Problem
During anisotropic plasma etching processes for via contacts, metal patterns, and passivation
openings, "sidewall residues" are frequently deposited on the f(~sist sidewalls. After the oxygen
plasma ashing process these deposits become metal oxides. Incomplete removal of these residues
interfere with the pattern definition and/or complete filling of via-holes. Thus, wet stripping
options must be available.
Etching Residue Removal Mechanism
Several different chemistries have been identified for removing aluminum etching residues.
Alkaline based positive resist developers, such as NaOH, tetram(~thylarnrnoniumhydroxide and
16
choHne, are known to attack aluminum • The hydroxyl ions attack the aluminum to form an
aluminum oxide hydrated anion (Equation 3).
Positive resist developers are limited to removing aluminum residues, but they do not remove
residues associated with multimetal systems such as Al/Si/Cu. They also are ineffective on
residues from polysiHcon plasma etch processes. Stringent process control must be exercised to
prevent resist attack and maintain critical dimension control.
One of the first, for feature sizes down to 1.0 micron, is the solvent/amine type strippers such as
identified in Table 2. The attack mechanism is a two step reaction starting with the formation of
hydroxyl ions, when the amine component in the stripper is hydrolyzed with water17 (Equation 4).
RNH 2 + H 20 -> RNH 3 + + OR [4]
<-
The aluminum residues are removed by the same reaction as shown in Equation 3.
OthE!r alternatives for the removal of the aluminum etching resid.ues after metal and via etch are
(1) a mixture of HF or BOE and ethylene glycol ether or (2) a mixture of nitric acid, acetic acid and
hydrofluoric acid. The active species in these mixtures are hydrogen ions [H+], fluoride ions [F],
and acetate ions [CH3COOl The hydrogen ion non-selectively attacks metal residues and the
fluoride ion non-selectively attacks silicon. The acetic acid reacts with aluminum to form a more
soluble aluminum acetate. The reactions are shown in Equations #5 to #8.
NH4F + ~O -> NH40H + HF [5]
HF + H:P -> H 3 0+ + F- [6]
HN03 + H 20 -> H+ + N03- ,[7]
CH3COOH + H 20 -> CH3 COo- + H+ f8]
These solutions require extreme process control to prevent excessive attack of critical metal and
oxide layers. In some device structures these solutions are not usable due to their non-selective
attack mechanisms.
OthE!r Etching Residues
Sub-micron devices have led to the use of multilevel interconnecting metals, such as Al/Si/Cu,
TiN, TiW, W, and WSi. These metal stacks produce different types of etching residues not removed
by the conventional solvent/amine stripper chemistry. Etching type chemistries, if used to remove
residues associated with advanced metal structures, require tight control and expensive automated
equipment.
~-------------------------li 5
Page tt-
7. Figure 3b: Coupled Diazide
Hydroxylamine is an extremely strong nucleophile that can attack the carbonyl groups. The result
is an increased solubility of the reacted product (oxime) in an alkaline medium, as illustrated in
Figure 4. ( "'"
c = 0 --- C --OH C --OH C === N -OH
/ /'
HO
/'~~ /(
~N
/
o xim.
OH
Figure 4: Nucleophilic Attack of Carbonyl Group
Polyimide Removal
The same unique nucleophilic attack mechanism of HDA takes place with cured polyimide
polymer structures, as illustrated in Figure 5. Laboratory tests have demonstrated the removal of
cured polyimide films with a HDA solution.
Figure 5: Nucloephilic Attack of Polyimide
Metal Halides Residue Removal
During plasma etching processes, such as metal etching, silicon oxide etching, and polysilicon
etching, hydroxyl groups in the photoresist react with metal halide gasses generated in the etching
chamber to form undesirable residues of organometallic compounds. The organometallic
compounds are shown in Figure 6. The compounds cause cross linking of the Novalak resin at the
metal centers, greatly reducing its solubility. On any subsequent oxygen plasma treatment, metal
oxides, e.g. Ti02 , TiO, A!;!03, and W02 would be formed and left behind.
o
~N2
~
~~~~?J=
o >=< c'V
I~O 0rY
~~ y
M=AI;Ti;W;Si
Figure 6: Chemical Reaction of Metal Halide
------------------------1, Page 7 tt-
8. Other stable metal halides, such as AIF3' WF5' WF6' WOF3' or TiF3 also remain on the wafer surface.
These salts and oxides are insoluble in water, dilute acids, or bases22, but they are removed in HDA
solutions. Reduction of these metallic species and subsequent formations of chelating complexes
playa role in the removal of these residues. Based on the oxidation/reduction potentials, the
metallic species that can be reduced by hydroxylamine are listed in Table 4.
The combination of HDA and an organic amine
T.ABLE 4: METALLIC REDUCTION BY form a strong reducing and complexing (ligating)
HYDROXYLAMINE22 solution. The insoluble metal oxide could be
Ag(I) _ Ag(O) reduced to a lower oxidation state and
Au(I1)_ Au(I) subsequently dtelated with the ligand to form a
Co(III) _ Co(I1) more soluble metal complex which could
ultimately end up in the solution.
Cr(VI)_ Cr(IV)
Cu(U) Cu(I) Hydroxylamine and organic amines can form
Fe(I1I) _ Fe(I1) coordination complexes through their nitrogen.
Pd(I1) Pd(1) atoms (e.g. Zn(NH20H)2CI2)' The proposed
Ti(lll) _Ti(l) mechan~sm of reduction, chelation, and
W(V) _ W(I1I) solublization results in removal of a number of
plasma generated etching residues without
attacking the pure metal surfaces.
EXPERIMENTAL CONDITION~
Four different stripping and cleaning solutions were chosen for t:he evaluation. They are listed in
Table #5. The first three were commercially available producl:s in general use. The fourth, a
buffered hydroxylamine solution developed by EKC Technology Inc. was a mixture of
hydroxylamine (e.g. NH2 0H) and 2 (2 aminoethoxy) ethanol (e.g. ~NCH2CH2OCH2CH20H).
TABLE 5: STRlPPING SOLUTIONS
-
Stripping Composition Temp.oC Time (Min.) Patent Number
,
NMP.I Alkanofamine 95 30 US 4617251
DMSOlMonoethanolamine 95 30 JK-64-42653
- I
DMAClDiethanolamine 100 30 US 4770713
Hydroxylamine Buffered 65 30 Patent Pending in U. S, I
So'lution Japan, Europe, Taiwan and
Korea
Sample wafers from various process steps were supplied by wenfer fabrication production lines.
The wafers were cleaned in different solutions heated according to the recommended process
tempE!ratures and for 30 minutes (Table 5). The cleaning took plaCie in either quartz or stainless steel
baths inside a standard wet bench. The wafer boats received intermittent manual agitation during
the snip cycle. After stripping, the wafers were transferred to a deionized cascade rinser for iniual
rinsing and finished with a cycle in a commercial spin/rinse dryer.
After cleaning the experimental wafers were compared for removal of surface contaminants. The
effect of the cleaning process on specific electrical parameters was also investigated.
-----l PagtTl1~---------------_._------------
-----'' c==~ @996EKeTechnology,Jnc.
l
9. EXPERIMENTAL RESULTS
Introduction
The '"hernical compositions of etch residues vary with wafer conditions and process parameters.
Laser Ionization Mass Absorption (LIMA) analysis confirmed tha,t the residue after via etching of
wafE'rs with TiN anti-reflective coating contained TiD as shown in Figure 7.
3 ~sn 92 11: 23: 37
Ii IIO
K
Na
,.'
>--"~-""'-=fe!o""""""-""'-""'''''''''-s'-!:o~o ..... ---"--="~"..'--:-:!s~:-=o~~~---'-~ilO~O-'---"---"-""""'~il"O
'
ION MASS (m/z)
Figure 7': Analysis of residue using LIMA showed the "sidewall
polymer" in Figure 8a contained oxide of titanium and some
organic residual.
Etch Residues
The following series of SEMs show the removal of etch residues after specific processes. In each
evaluation the HDA process successfully removed the particular etch residue.
Figure 8a - Etching residue after plasma Figure 8b - ThE' metal oxide residue is
ashing. removed by the Hydroxylamine buffered
solution at 65°C for 10 minutes.
-------------------------1. Page 9 tr
11. Figure 12a - The via residue is decorated Figure 12b - The via residue is completely
on the wafer surface after the wafer was removed after being processed through
cleaned in a mixture of DMSO/MEA, Hydroxylamine buffered solution at 6S'C
JK-64-426S3 at 9S'C for 30 minutes and for 30 minutes.
followed with an isotropic etch.
Figure 13a - Polysilicon etching residue Figure 13b - No residue or gate oxide
after plasma ashing. undercut after processing with the
Hydroxylamine buffered solution.
i
. Figure 14a - Polysilicon etching residue Figure 14b - The polysilicon residue is
on the polysilicon line (with structure of completely removed after the wafer was
Nitride/TiSi/Polysilicon) after 02 plasma cleaned in a Hydroxylamine buffered
ashing. solution at 65'C for 30 minutes.
--------------------------1, Page 11 tJ--
13. C/V Shift, VT Shift And TOF-SIMS Analysis
Table 5 lists the results of cleaning wafers in an NMP solvent solution compared with cleaning in
buffered HDA solution.
TABLE 6' COMPARISON OF NMP AND EKC·265 PROCESSES
Chemical Sodium lTemp jfime Avg. Vfb ~TLo-VTHi Damaged
Purity I
I/Min.) (+ to -bias) BPSG
N-Methyl-Pyrrolidone f ppb ~O°C ,20 2.04 1.28-2.92 3.5E+ 13
(NMP) . .ons/Cm 2
!EKC 265 100 ppb k>5°C ~O 0.21 3.08-3.13 1.2E+13
,
I ons/Cm 2
The results indicate that the wafers cleaned in HDA solution measured an order of magnitude
lower Vfb (flat band voltage shift), 0.21 to 2.04 volts. The range (difference between VT 10 and VT
Hi) of VT shift was 0.05 compared to 0.64 for the NMP. The boron-phosphorus silicate glass layer
(BPSG) damage evaluation showed a lower level of damage for the HDA cleaned wafers. Overall,
the incidence of mobile ionic contamination was lower with the HDA, despite the fact that the HDA
solution initially contained a higher level ofsodium. The conclusion is that the HDA buffer solution
is better at holding the mobile ions in the liquid phase as compared to the solvent/amine stripper
solution. .
'fABLE 7: INCREASE IN MOBILE ION CONCENTRAnON FROM PLASMA ASHING
Substrate Ions/Cm 2 ,
Damaged Oxide 4.4E+1O
Damaged BPSG 1.2E+ 13 ,
~PSG 5.4E+ll
Post Plasma Mobile Ion Contamination
The search for the cause of mobile ionic contamination in processes tends to focus on the
contamination level of the process chemicals. In a separate study wafers were measured for ion
density immediately after a plasma ashing step (no cleaning step). TOF-SIMS analyses were
performed to detennine the ion densities. The results presented in Table 7 and Figure IS
demonstrate that there are high concentration levels of ions found on the wafers that are directly
associated with a plasma process.
1.60E+ 13
1.40E+13
1.20E+ 13
E I.OOE+13
~ 8.00E+12
<::
oS 6.00E+12
4.00E+12
2.00E+12
O.OOE+OO.jool,----I:::Z.------r----L.~-----r-- ..... - - ,
--
Damaged Damaged BPSG
Oxide BPSG
Figure 15: TOF-SIMS Analysis of Mobile Ions
----------------------------ll, Page 13 tt--
15. Mr. Wai Mun Lee is the Vice President of Research & Developmemt for EKC Technology, Inc. and
is responsible for thE! development and characterization of new photoresist strippers and wafer
cleaning products. He holds several patents on novel chemical compositions for removing posi-
tive and negative resists from wafer surfaces. Mr. Lee earned a BS. in Chemical Engineering at
the University of California, Berkeley, California.
He joined EKC Technology, Inc. in 1981. Previous to that he held research chemist positions with
the Specialty Coating Department of Hercules, Inc., Wilmington, DE and Pigments and Additives
Division of Ciba Geigy Corp., Ardsley, NY.
ACKNOWLEDGEMENTS
The author would like to thank the following individuals and their companies for their
encouragement, advice and wafer samples. I
• Dr. M. Haslam and Dr. Spinner, Advanced Technology Development, S.G.S. Thompson,
Carrolton, TX.
• Mr. J. Kava, Mr. J. Hamilton and Ms. W. M. Chu, LSI Logic Corp., Milpitas, CA.
• Dr. P. Koch, Mr. L. Wilson and Mr. M. Nghyen, Submicron Development Center,
Advanced Micro Devices, Sunnyvale, CA.
The author expresses special thanks to Mr. Russ Kuroda nd Mr. Chiu Tse for their indispensable
help taking the SEM pictures. He also thanks Peter Van Zant for assistance with editing the
manuscript and graphic design.
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