A theoretical model for the electrical properties of chromium thin films sputter deposited at oblique incidence

Abstract

Chromium thin films are prepared by magnetron sputtering using the GLancing Angle Deposition (GLAD) method. The electrical conductivity of the films exhibiting an inclined columnar structure is investigated. An analytical three dimensional model is proposed in order to predict the evolution of the electrical conductivity as a function of the columns orientation. This model is based on two types of electron scattering mechanisms, which are simultaneously operational: the isotropic background scattering at the grain boundary and the scattering due to electron dispersion at the column boundary. The developed analytical expressions enable systematic studies of different process and film parameters, especially the column angle β as well as the sputtering pressure used during the GLAD deposition. The theoretical and experimental results are compared. It is found that the column angle β must reach a threshold value to significantly reduce the electrical conductivity of chromium thin films close to one order of magnitude. The effect of the sputtering pressure on the films

Metal-to-Dielectric Transition Induced by Annealing of Oriented Titanium Thin Films

“…Before increasing the temperature, conductivity at room temperature is s 293K = 1.56´10 5 S m -1 . This value is one order of magnitude lower than those previously measured for the titanium film deposited without GLAD (s 293K = 1.22´10 6 S m -1 for a = 0°) [12].…”

“…Before increasing the temperature, conductivity at room temperature is s 293K = 1.56´10 5 S m -1 . This value is one order of magnitude lower than those previously measured for the titanium film deposited without GLAD (s 293K = 1.22´10 6 S m -1 for a = 0°) [12].As the temperature rises up to 333 K and as expected for metallic compounds, conductivity is linearly reduced. A further increase of temperature up to 523 K leads to a non linear evolution of the conductivity versus temperature and drops down to s 523K = 2.31´10 4 S m -1 .…”

Correlation between structural and optical properties of WO3 thin films sputter deposited by glancing angle deposition

“…Among these oxide compounds, tungsten oxide 33 thin films have been extensively investigated due to their important applications as active layers for 34 electrochromic window devices [1][2][3][4], sensors for toxic gases [5][6][7][8], optical coatings with high 35 refractive index [9,10] or transparent and low resistive oxide materials [11,12]. It is well known 36 that many chemical and physical characteristics of metal oxide thin films are strongly connected to 37 their chemical composition, especially the oxygen-to-metallic concentrations ratio, which can be 38 tuned in order to get a metallic, semi-conducting or insulating behaviour according to the metalloid 39 content in the film [13][14][15][16]. However, playing with the chemical composition is not the only 40 approach to tune the properties of metal oxide thin films.…”

“…1b and 1d). where column angles are often lower than those calculated with various ballistic rules [37,38].…”

Theoretical and experimental characterization of TiO2 thin films deposited at oblique angles

“…In general, these microstructures are caused by the shadowing of the deposition flux when arriving at the growing film, which makes tall surface features prevent the deposition under their shadow. This produces a competitive growth among surface motives, which ends up in the development of tilted structures oriented towards the incoming deposition flux [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The use of these thin films as a host for the development of nanostructured composite materials is another potential application quite dependent on the final topology of the films that has been widely investigated by our group [20][21][22][23].…”