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Post-deposition Annealing (post-deposition + annealing)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Control of the Morphology and Structural Development of Solution-Processed Functionalized Acenes for High-Performance Organic Transistors

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2009
Jung Ah Lim
Abstract Solution-processable functionalized acenes have received special attention as promising organic semiconductors in recent years because of their superior intermolecular interactions and solution-processability, and provide useful benchmarks for organic field-effect transistors (OFETs). Charge-carrier transport in organic semiconductor thin films is governed by their morphologies and molecular orientation, so self-assembly of these functionalized acenes during solution processing is an important challenge. This article discusses the charge-carrier transport characteristics of solution-processed functionalized acene transistors and, in particular, focuses on the fine control of the films' morphologies and structural evolution during film-deposition processes such as inkjet printing and post-deposition annealing. We discuss strategies for controlling morphologies and crystalline microstructure of soluble acenes with a view to fabricating high-performance OFETs. [source]

Atomic Layer Deposition of BaTiO3 Thin Films,Effect of Barium Hydroxide Formation

CHEMICAL VAPOR DEPOSITION, Issue 5 2007
M. Vehkamäki
Abstract Barium titanate thin films are grown by atomic layer deposition (ALD) at 340,°C from barium cyclopentienyl and titanium methoxide precursors. H2O is used as the oxygen source. Binary reactions of Ba(tBu3C5H2)2 and H2O are first studied separately in BaO deposition and are found to result in a hydration/dehydration cycle, which is strongly influenced by the process temperature. Self-limiting growth of amorphous barium titanate films becomes possible when Ti(OMe)4 , H2O growth cycles are mixed as well as possible with Ba(tBu3C5H2)2 , H2O cycles. The as-deposited amorphous films are crystallized by post-deposition annealing at 600,°C. Permittivities of 15 and 70 are measured for as-deposited and post-deposition annealed films, respectively. A charge density of 1.9 ,C cm,2 (equivalent oxide thickness of 1.8,nm) and leakage current density ,,1,×,10,7,A,cm,2 were achieved at 1,V bias with a 32,nm thick Ba,Ti,O film in a Pt electrode stack annealed at 600,°C. [source]

Liquid-Injection MOCVD of ZrO2 Thin Films using Zirconium Bis(diethlyamido)-bis(di- tert -butylmalonato) as a Novel Precursor,

CHEMICAL VAPOR DEPOSITION, Issue 5 2006
R. Thomas
Abstract The stabilization of highly reactive amide complexes of zirconium diethylamide with malonates as chelating ligands leads to a stable six-coordinated monomeric complex which shows promise for CVD applications. This novel precursor, zirconium bis-(diethylamido)bis(di- tert -butylmalonato) zirconium, [Zr(NEt2)2(dbml)2], has been characterized and tested in a production-type MOCVD reactor for ZrO2 thin-film deposition. Up to 450,°C, the ZrO2 films are amorphous, and above 475,°C films they are crystalline. Atomic force microscopy (AFM) shows a lower roughness (,2.5Å) for as-deposited amorphous films compared to crystalline films (,6.0,Å); however, smooth crystalline films can be obtained by post-deposition annealing of amorphous films. Electrical properties are investigated for Pt/ZrO2/SiOx/Si capacitor structures. Relative dielectric permittivity reaches a bulk value of 24, and leakage currents for typically 4,nm thick films are below 10,4,A,cm,2 at a bias of ,1,V. Hence, the precursor shows promising properties for possible application in the deposition of high- k gate oxide (MIS) and high- k dielectric (MIM) structures. [source]

Dehydrohalogenation in Alpha-Functionalized Poly- p -xylylenes,

CHEMICAL VAPOR DEPOSITION, Issue 4 2006
P. Carrow
Abstract Poly(p -xylylene) or parylene has been around for more than a half a century. It is typically deposited by the Gorham method from [2.2] paracyclophane. However, another method is via alpha-derivatives of p -xylene. Both poly(,-bromo- p -xylylene) and poly(,-chloro- p -xylylene) have been successfully deposited by this route through predominately HBr or HCl dehydrohalogenation gas-phase reactions. In the study reported here we synthesize ,,,,,-tribromo- p -xylene and ,-bromo-,,,,,-dichloro- p -xylene as CVD precursors to yield ,,,- and ,,,,-dihalogenated poly(p -xylylene)s to try to convert them, via post-deposition annealing, to poly(phenylene ethynylene) (PPE). PPE and its intermediate poly(phenylene vinylene) (PPV), have potentially better thermal and oxidative properties, and in addition they are both photoluminescent. The as-deposited and annealed thin films have been characterized by Rutherford backscattering spectrometry (RBS), infrared spectroscopy, and UV-vis spectrophotometry, and electrically tested by dielectric constant, bias-temperature stress (BTS), and leakage current. It is found that the thin films crystallizes concurrent with the formation of PPV and possibly converts to PPE but has much residual chlorine and bromine. However, PPV exhibits excellent stability in contact with copper and is more thermally stable than poly(p -xylylene). [source]