The use of camera obscura in sputter deposition

Camera obscura or pinhole camera is an optical device where object is recorded through a small pinhole. A similar experiment was performed in a sputter deposition system. A shield with small aperture (1 mm in diameter) was positioned between the target and the glass substrate. Only the material sputtered in direction of the aperture was deposited on the substrate. In this way a direct image of the target was recorded (similar to a camera obscura). The thickness profile of the image made by the camera obscura is proportional to the flux of emitted particles from the target. Experiments were conducted in a triode sputtering system and in a magnetron sputtering system. The camera obscura was used to study sputtering from different two-element segmental targets: Ti–Al, Al–W, Al–Cu, Ti–W, Ni–C. The thickness profiles of deposits were measured by profilometer. These simple experiments were performed to give a better understanding of the sputtering process.