Adhesion of Ti and TiC Coatings on PMMA Subject to Plasma Treatment: Effect of Intermediate Layers of Al2O3 and TiO2 Deposited by Atomic Layer Deposition

Magnetron sputtered metal and metal compound films generally show very poor adhesion to PMMA; this limits the use of the polymer for components which are wear or scratch resistant or have a decorative finish. We have shown that adhesion could be significantly improved by a duplex process where a nanometer-scale thickness adhesion layer of TiO 2 or Al 2 O 3 was deposited by low temperature atomic layer deposition (ALD) prior to magnetron sputtering. The metal precursors used for TiO 2 and Al 2 O 3 were TDMAT and TMA, respectively, and ozone was used as a source of oxygen in both processes. This process was followed by deposition of the metal/metal carbide layer using pulsed DC reactive magnetron sputtering. With the presence of the ALD adhesion layer, the pull-off adhesion strength increased with its thickness until a point where the failure mechanism was due to cohesive disruption of the substrate material itself. It has been shown that the ALD deposited layers protect the PMMA against plasma damage during the sputtering process by blocking both direct ion damage and disruption of the polymer structure by ultra-violet radiation.

[1]  F. Hong,et al.  Adhesion improvements for diamond-like carbon films on polycarbonate and polymethylmethacrylate substrates by ion plating with inductively coupled plasma , 2003 .

[2]  Do‐Heyoung Kim,et al.  Characteristics of atomic layer deposited TiO[sub 2] films and their photocatalytic activity , 2006 .

[3]  Giovanni Dietler,et al.  Interaction of low-energy ions (< 10 eV) with polymethylmethacrylate during plasma treatment , 1995 .

[4]  H. Nozoye,et al.  Morphology and chemical structure of poly(methyl methacrylate) surfaces and interfaces: restructuring behavior induced by the deposition of SiO2 , 2003 .

[5]  S. Rajendran,et al.  Conductivity studies on PVC/PMMA polymer blend electrolyte , 2000 .

[6]  Soon-Gil Yoon,et al.  Very Thin TiO2 Films Prepared by Plasma Enhanced Atomic Layer Deposition (PEALD) , 2004 .

[8]  Norbert Kaiser,et al.  Transparent thermoplastic polymers in plasma-assisted coating processes , 2003 .

[9]  S. Rajendran,et al.  Lithium ion conduction in PVC–LiBF4 electrolytes gelled with PMMA , 2000 .

[10]  Norbert Kaiser,et al.  Surface modification of PMMA by DC glow discharge and microwave plasma treatment for the improvement of coating adhesion , 2001 .

[11]  M. Heyns,et al.  Characterization of ALCVD-Al2O3 and ZrO2 layer using X-ray photoelectron spectroscopy , 2002 .

[12]  M. Wertheimer,et al.  Oxidation and ablation of polymers by vacuum-UV radiation from low pressure plasmas , 1997 .

[13]  R. French.  Electronic Band Structure of {Al2O3}, with Comparison to Alon and {AIN} , 1990 .

[14]  S. Rajendran,et al.  an electrochemical investigation on PMMA/PVdF blend-based polymer electrolytes , 2001 .

[15]  K. Sreenivasan,et al.  In vitro calcium phosphate growth over surface modified PMMA film. , 2003, Biomaterials.

[16]  M. Wertheimer,et al.  Industrial processing of polymers by low-pressure plasmas: the role of VUV radiation , 1999 .

[17]  R. Wilken,et al.  Subsurface chemistry in the plasma treatment of polymers , 1999 .

[18]  Celso U. Davanzo,et al.  Properties of titanium oxide films obtained by PECVD , 2000 .

[19]  K. S. Shamala,et al.  Studies on optical and dielectric properties of Al2O3 thin films prepared by electron beam evaporation and spray pyrolysis method , 2004 .

[20]  S. Wongnawa,et al.  Mixed amorphous and nanocrystalline TiO2 powders prepared by sol–gel method: Characterization and photocatalytic study , 2008 .

[21]  V. Omarjee,et al.  Ti Source Precursors for Atomic Layer Deposition of TiO2, STO and BST , 2008 .

[22]  Do‐Heyoung Kim,et al.  Characteristics of TiOx films prepared by chemical vapor deposition using tetrakis-dimethyl-amido-titanium and water , 2006 .

[23]  Yolanda Y. Davidson,et al.  Surface modification of poly(methyl methacrylate) used in the fabrication of microanalytical devices. , 2000, Analytical chemistry.

[24]  Justin S. Mecomber,et al.  Covalent immobilization of proteases and nucleases to poly(methylmethacrylate) , 2003, Analytical and bioanalytical chemistry.

[25]  Louis Schlapbach,et al.  Modification of the micro- and nanotopography of several polymers by plasma treatments , 2003 .

[26]  Halina Kaczmarek,et al.  The influence of UV-irradiation and support type on surface properties of poly(methyl methacrylate) thin films , 2006 .

[27]  J. Goddard,et al.  Polymer surface modification for the attachment of bioactive compounds , 2007 .

[28]  Simon D. Elliott,et al.  Ozone-Based Atomic Layer Deposition of Alumina from TMA: Growth, Morphology, and Reaction Mechanism , 2006 .

[29]  Laurie Brown,et al.  Epoxy resins as stamps for hot embossing of microstructures and microfluidic channels , 2005 .

[30]  L. Martinu,et al.  Tailoring the adhesion of optical films on polymethyl-methacrylate by plasma-induced surface stabilization , 2005 .

[31]  M. Wertheimer,et al.  Vacuum Ultraviolet Irradiation of Polymers , 1999 .

[32]  F. Rubio,et al.  DSC and FT-IR analysis of the drying process of titanium alkoxide derived precipitates , 1999 .

[33]  S. George,et al.  Nucleation and Growth during Al2O3 Atomic Layer Deposition on Polymers , 2005 .

[34]  Cheng-Wey Wei,et al.  Direct-write laser micromachining and universal surface modification of PMMA for device development , 2004 .