Pulsed Laser Assisted Chemical Etch for analytic surface preparation

ABSTRACTBarium titanate (BaTiO3) is of interest for use in a number of thin-film applications in electronic and optoelectronic devices. For these devices the formation of epitactic films of the correct stoichiometry and phase is essential. The substrate is important during the early stages of growth in the establishment of epitaxy, factors such as lattice mismatch, surface preparation and crystallographic orientation can all affect film nucleation and growth. In this study thin-films of BaTiO3 have been formed using the pulsed-laser ablation technique. The early stages of film growth have been studied directly using transmission electron microscopy by examination of very thin films deposited onto specially prepared electron-transparent thin-foil substrates.

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Epitaxial growth of GaN thin films on sapphire (0001) by pulsed laser deposition: influence of surface preparation and nitridation

Materials Science and Engineering B ◽

10.1016/s0921-5107(00)00779-0 ◽

2001 ◽

Vol 82 (1-3) ◽

pp. 68-70 ◽

Cited By ~ 6

Author(s):

J.L Deiss ◽

Ch Hirlimann ◽

J.L Loison ◽

M Robino ◽

G Versini

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Epitaxial Growth ◽

Pulsed Laser ◽

Surface Preparation ◽

Laser Deposition

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Preparation of Wafer Level Packaged Integrated Circuits Using Pulsed Laser Assisted Chemical Etching

ISTFA 2012: Conference Proceedings from the 38th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2012p0491 ◽

2012 ◽

Author(s):

Robert Chivas ◽

Niru Dandekar ◽

Scott Silverman ◽

Roddy Cruz ◽

Michael DiBattista

Keyword(s):

Integrated Circuits ◽

Chemical Etching ◽

Focused Ion Beam ◽

Ion Beam ◽

Pulsed Laser ◽

Surface Preparation ◽

Wafer Level ◽

Dimensional Control ◽

Dry Process ◽

Ultra High Purity

Abstract Pulsed Laser Assisted Chemical Etching (PLACE) is an advanced method of surface preparation that etches backside silicon to ultra-thin remaining layer thickness for Focused Ion Beam (FIB) circuit edit and failure analysis of Wafer Level Packages (WLP). PLACE can achieve ultra-high purity and fine dimensional control since it is a dry process relying on pyrolytic vapor phase reactions initiated, and constrained, by a pulsed laser.

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Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089652 ◽

1991 ◽

Vol 49 ◽

pp. 1068-1069

Author(s):

M. Grant Norton ◽

C. Barry Carter

Keyword(s):

Thin Film ◽

Thin Films ◽

Laser Ablation ◽

Substrate Surface ◽

Pulsed Laser ◽

Pulsed Laser Ablation ◽

Thin Film Deposition ◽

Film Deposition ◽

Laser Ablation Process ◽

Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

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EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139068 ◽

1995 ◽

Vol 53 ◽

pp. 538-539

Author(s):

E Y. Wang ◽

J. T. Cherian ◽

A. Madsen ◽

R. M. Fisher

Keyword(s):

Steel Surface ◽

Surface Preparation ◽

Treatment Method ◽

Chrome Plating ◽

Transmission Electron ◽

Alloy Steels ◽

Pre Treatment ◽

Hard Chrome ◽

Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

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Selective Corrosion of brazed joint between BNi-2 filler metal and stainless steel 316

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163551 ◽

1996 ◽

Vol 54 ◽

pp. 218-219

Author(s):

H. S. Kim ◽

R. U. Lee

Keyword(s):

Stainless Steel ◽

Filler Metal ◽

Surface Preparation ◽

Optical Microscope ◽

Heating Element ◽

Incomplete Fusion ◽

Atmospheric Conditions ◽

Leak Test ◽

High Temperature Side ◽

Inconel 600

A heating element/electrical conduit assembly used in the Orbiter Maneuvering System failed a leak test during a routine refurbishment inspection. The conduit, approximately 100 mm in length and 12 mm in diameter, was fabricated from two tubes and braze-joined with a sleeve. The tube on the high temperature side (heating element side) and the sleeve were made of Inconel 600 and the other tube was stainless steel (SS) 316. For the filler metal, a Ni-Cr-B brazing alloy per AWS BNi-2, was used. A Helium leak test spotted the leak located at the joint between the sleeve and SS 316 tubing. This joint was dissected, mounted in a plastic mold, polished, and examined with an optical microscope. Debonding of the brazed surfaces was noticed, more pronounced toward the sleeve end which was exposed to uncontrolled atmospheric conditions intermittently. Initially, lack of wetting was suspected, presumably caused by inadequate surface preparation or incomplete fusion of the filler metal. However, this postulation was later discarded based upon the following observations: (1) The angle of wetting between the fillet and tube was small, an indication of adequate wetting, (2) the fillet did not exhibit a globular microstructure which would be an indication of insufficient melting of the filler metal, and (3) debonding was intermittent toward the midsection of the sleeve.

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Microanalysis of silicate glass films grown on α-Al2O3 by pulsed-laser deposition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100148022 ◽

1993 ◽

Vol 51 ◽

pp. 438-439

Author(s):

Michael P. Mallamaci ◽

James Bentley ◽

C. Barry Carter

Keyword(s):

Liquid Phase ◽

Single Crystal ◽

Pulsed Laser Deposition ◽

Pulsed Laser ◽

Ceramic Materials ◽

Laser Deposition ◽

Triple Junctions ◽

Ion Milling ◽

Multicomponent Oxides ◽

Glass Films

Glass-oxide interfaces play important roles in developing the properties of liquid-phase sintered ceramics and glass-ceramic materials. Deposition of glasses in thin-film form on oxide substrates is a potential way to determine the properties of such interfaces directly. Pulsed-laser deposition (PLD) has been successful in growing stoichiometric thin films of multicomponent oxides. Since traditional glasses are multicomponent oxides, there is the potential for PLD to provide a unique method for growing amorphous coatings on ceramics with precise control of the glass composition. Deposition of an anorthite-based (CaAl2Si2O8) glass on single-crystal α-Al2O3 was chosen as a model system to explore the feasibility of PLD for growing glass layers, since anorthite-based glass films are commonly found in the grain boundaries and triple junctions of liquid-phase sintered α-Al2O3 ceramics.Single-crystal (0001) α-Al2O3 substrates in pre-thinned form were used for film depositions. Prethinned substrates were prepared by polishing the side intended for deposition, then dimpling and polishing the opposite side, and finally ion-milling to perforation.

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TEM sample preparation of wear-tested room-temperature pulsed-laser-deposited thin films of MoS2 by ultramicrotomy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151428 ◽

1993 ◽

Vol 51 ◽

pp. 1118-1119

Author(s):

Pamela F. Lloyd ◽

Scott D. Walck

Keyword(s):

Thin Films ◽

Sample Preparation ◽

Room Temperature ◽

High Vacuum ◽

Pulsed Laser ◽

Ultra High Vacuum ◽

Wear Testing ◽

Preparation Technique ◽

Cross Sectional ◽

Aerospace Applications

Pulsed laser deposition (PLD) is a novel technique for the deposition of tribological thin films. MoS2 is the archetypical solid lubricant material for aerospace applications. It provides a low coefficient of friction from cryogenic temperatures to about 350°C and can be used in ultra high vacuum environments. The TEM is ideally suited for studying the microstructural and tribo-chemical changes that occur during wear. The normal cross sectional TEM sample preparation method does not work well because the material’s lubricity causes the sandwich to separate. Walck et al. deposited MoS2 through a mesh mask which gave suitable results for as-deposited films, but the discontinuous nature of the film is unsuitable for wear-testing. To investigate wear-tested, room temperature (RT) PLD MoS2 films, the sample preparation technique of Heuer and Howitt was adapted.Two 300 run thick films were deposited on single crystal NaCl substrates. One was wear-tested on a ball-on-disk tribometer using a 30 gm load at 150 rpm for one minute, and subsequently coated with a heavy layer of evaporated gold.

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