Investigation of improving the thickness uniformity of the film formed by cathode sputtering

The way of improving the thickness uniformity of the films formed by cathode sputtering is presented. It is shown from computation that under the bombardment of the ions with strong electric field strength, the thickness uniformity and the homogeneous range, for the cathode target made by multi-crystal or non-crystal material, can be greatly improved and expanded if the square window is holed at the centre of the target and the distance between the target and the substract is properly selected. In experiment, the uniform range with the square size of 11 cm x 11 cm and, the nonuniformity less than 3% have been obtained by using the cathode target with the size of 10 cm x 10 cm and the window located at its centre with the size of 5 cm x 5 cm