Specific Process Knowledge/Thin film deposition/Deposition of Gold/Adhesion layers: Difference between revisions
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In contrast to the case with the Ti adhesion layer, TEM bright field analysis of the 2nm Cr/2nm Au sample shows a single continuous layer (Fig. 4a). The AFM RMS surface roughness is 1.2 nm (Fig. 4b). Increasing the nominal Au thickness to 20 nm for the 2nm Cr/20nm Au sample, the film still presented a single-layer morphology (Fig. 4c), while the RMS surface roughness decreased to 0.6 nm (Fig. 4d). | In contrast to the case with the Ti adhesion layer, TEM bright field analysis of the 2nm Cr/2nm Au sample shows a single continuous layer (Fig. 4a). The AFM RMS surface roughness is 1.2 nm (Fig. 4b). Increasing the nominal Au thickness to 20 nm for the 2nm Cr/20nm Au sample, the film still presented a single-layer morphology (Fig. 4c), while the RMS surface roughness decreased to 0.6 nm (Fig. 4d). | ||
<gallery widths=" | <gallery widths="350px" heights="350px" perrow="2" halign="center"> image:Picture5.png|Fig. 3: TEM cross section images and 300x300 nm AFM images of the 2nm Ti/2nm Au sample (a-b) and of the 2nm Ti/20nm Au sample (c-d). | ||
image:Picture7.png|Fig. 4: TEM cross section images and 300x300 nm AFM images of the 2nm Cr/2nm Au sample (a-b) and of the 2nm Cr/20nm Au sample (c-d). </gallery> | image:Picture7.png|Fig. 4: TEM cross section images and 300x300 nm AFM images of the 2nm Cr/2nm Au sample (a-b) and of the 2nm Cr/20nm Au sample (c-d). </gallery> | ||
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Fig. 6a represents two Au islands having different crystal orientations. In particular they have the (111)- and (100)-facets, respectively, parallel to the substrate surface. The growth of these islands is dependent on their orientation (Fig. 6b): for Au, which has a face-centered cubic unit cell, the (100) surface has a higher surface energy than the (111) surface, and to minimize energy, the (100) surface grows faster. Islands having (100) or (110) facets parallel to the substrate grow faster in the vertical direction, while islands with (111) facets parallel to the substrate grow faster laterally. The result is a continuous film, having laterally larger and flatter islands with [111] crystal direction, and laterally smaller but taller islands with [100] and [110] orientations. | Fig. 6a represents two Au islands having different crystal orientations. In particular they have the (111)- and (100)-facets, respectively, parallel to the substrate surface. The growth of these islands is dependent on their orientation (Fig. 6b): for Au, which has a face-centered cubic unit cell, the (100) surface has a higher surface energy than the (111) surface, and to minimize energy, the (100) surface grows faster. Islands having (100) or (110) facets parallel to the substrate grow faster in the vertical direction, while islands with (111) facets parallel to the substrate grow faster laterally. The result is a continuous film, having laterally larger and flatter islands with [111] crystal direction, and laterally smaller but taller islands with [100] and [110] orientations. | ||
<gallery widths=" | <gallery widths="400px" heights="400px" perrow="2" halign="center"> image:Picture2.png|Fig. 5: TKD inverse pole figure z-direction (IPFZ) map of the growth direction (a) and grain size distribution (b) of the 20nm Au sample. | ||
image:Picture3.png|Fig. 6: (a) Schematic representation of [111] and [100] Au islands on a SiO2 substrate. The crystal direction is referred parallel to the substrate surface. (b) Representation of the orientation-driven growth of the islands on the substrate: the {100} facets grow faster than {111} ones in order to decrease surface energy. </gallery> | image:Picture3.png|Fig. 6: (a) Schematic representation of [111] and [100] Au islands on a SiO2 substrate. The crystal direction is referred parallel to the substrate surface. (b) Representation of the orientation-driven growth of the islands on the substrate: the {100} facets grow faster than {111} ones in order to decrease surface energy. </gallery> | ||