Materials Research Corporation

Arnold J Aronson

Steven D Hurwitt

Walter H Class

Charles Van Nutt

Michael L Hill

Jon A Roberts

Karl J Armstrong

A plasma confining magnetic field is generated over the sputtering region of a sputtering target with a critical field line which determines the shape of the plasma. The critical field line is progressively flattened over the course of the life of the target as the target erodes. Preferably, the magnet is configured with poles spaced around the portion of the target below the sputtering region to provide a magnetic field that flattens as its strength decreases. A regulated power supply maintains a regulated power level that is increased as the target erodes to maintain a constant deposition rate. The voltage delivered by the power supply is maintained at or above a constant level by progressively decreasing the current to an electromagnet to progressively reduce the field strength and flatten the field. As a result of the invention, the erosion groove of the target is broadened and the number of wafers coated by the target during its life is increased.

Method of enhancing the performance of a magnetron sputtering target

A three step planarization method for planarizing aluminum or aluminum alloy in via and trench features of a wafer includes first, high rate deposition in the absence of heat, followed by low rate deposition in the presence of heat, and finally, high rate deposition with continued supply of heat to the wafer. Bias may be used. Deposition is preferably continuous and uninterrupted from the beginning of the first step until the end of the third step. The first step is limited in duration in order to produce a relatively thin layer which geometrically covers the inside surfaces of the feature. The duration of the second step is selectable, but is preferably based upon the temperature of the heat applied to the wafer and a characteristic size of the feature. The third step deposition completes the thickness of the film.

Planarization method

A cathode assembly for use in a magnetron sputtering system, the system having a cathode assembly with parallel elongated target segments which are formed substantially of a material which is desired to be sputter-deposited onto a substrate. The elongated target segments are each provided with a material removal surface which is inclined toward the other segment with respect to the plane of the substrate. Such inclination permits the material which is removed from the target bars to be focused onto a relatively narrow area, thereby improving the efficiency of the sputtering operation and reducing machine down-time for cleaning and vacuum pumping. In other embodiments, end target segments are provided for improving the efficiency of film deposition near the ends of the elongated bars. The end target segments are provided with material removal surfaces which are also inclined, and connect with the elongated target segments to form a rectangular frame arrangement.

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Pomona, NY, United States of America

Arnold J Aronson