Materials Research Corporation

Israel Wagner

Steven D. Hurwitt

Charles N. Van Nutt

Robert G. Hieronymi

Robert G Hieronymi

Steven D Hurwitt

Charles Van Nutt

Walter H Class

Richard C Edwards

Donald A Messina

Charles N Van Nutt

A target of a thickness, which varies across its radius according to the amount of material required to be sputtered, is supported in a nest in a chamber of a sputter coating apparatus. Positioned behind the nest is a rotating magnet carrier having arranged thereon in a closed loop a permanant or electro magnetic strip, but preferably a flexible permanently magnetic material, with portions near the rim of the target and portions near, but not on, the target center about which the magnet rotates. The magnetic loop is transversely polarized with one pole toward the target rim and one toward the target center so that its field will enclose the rim of the target within a magnetic tunnel that traps a plasma over the target. Lumped magnets across the center from the strip support the plasma near the center so as to cause some sputtering at the target center. Other lumped magnets adjacent the strip help sharpen the field so that a desired distribution of sputtering can be achieved. Enclosed in a sealed space behind and in thermal contact with the target nest is the carrier from which the magnets project to facilitate the flow of cooling fluid across the back surface of the nest to cool the target as the carrier rotates.

Target cooling and support for magnetron sputter coating apparatus

A re-entrant plug structure is disclosed which extends inside a processing chamber containing an ionized plasma in proximity to the plasma to physically displace the ionized plasma and selectively controllably vary concentration of ionized gas particles over the surface of a wafer to be sputter etched which is supported inside the chamber. The variation of concentration of the ionized plasma allows the selectively controllable variation of sputter etch rates on the surface of the wafer. The re-entrant plug structure may be formed as part of the enclosure cover of the processing chamber or may be a separable moveable unit which is inserted into the plasma through an opening in the processing chamber. The re-entrant plug may be of various lengths, diameters and shapes to displace and shape the ionized plasma. In an alternative embodiment of the invention, the plug contains a permanent or electromagnet which further magnetically displaces and shapes the plasma in addition to the physical displacement caused by the re-entrant plug.

Plasma shaping plug for control of sputter etching

A target of a thickness, which varies across its radius according to the amount of material required to be sputtered, is supported in a nest in a chamber of a sputter coating apparatus. Positioned behind the nest is a rotating magnet carrier having arranged thereon in a closed loop a permanent or electro magnetic strip, but preferably a flexible permanently magnetic material, with portions near the rim of the target and portions near, but not on, the target center about which the magnet rotates. The magnetic loop is transversely polarized with one pole toward the target rim and one toward the target center so that its field will enclose the rim of the target within a magnetic tunnel that traps a plasma over the target. Lumped magnets across the center from the strip support the plasma near the center so as to cause some sputtering at the target center. Other lumped magnets adjacent the strip help sharpen the field so that a desired distribution of sputtering can be achieved. Enclosed in a sealed space behind and in thermal contact with the target nest is the carrier from which the magnets project to facilitate the flow of cooling fluid across the back surface of the nest to cool the target as the carrier rotates.

Magnetron sputter coating method and apparatus with rotating magnet

A sputter coating apparatus displays set and alternative machine parameters, entered or calculated from entered or measured data, for selection by the operator. The apparatus performs a sputter coating process to produce sputter coated articles in accordance with the selected machine parameters. Process parameters familiar to the person creating the process, such as desired coating thickness and desired deposition rate, may be entered by the operator. Measured data such as actual coating thickness at a plurality of points on a previously processed wafer may be entered by an operator or automatically measured from a wafer. Alternative machine parameters such as target sputtering power may be entered by an operator or calculated from entered process parameters or measured data. The operator selects and initiates a process in accordance with the selections by entering commands. The machine parameters control separately the sputtering from different regions of the sputtering surface of a one piece sputtering target by alternately energizing different plasmas over the different target regions and energizing the target in accordance with different machine parameters.

Sputter coating process control method and apparatus

A bias sputter coating apparatus is provided with a cathode target assembly having a central electrode which is maintainable at an adjustable voltage level which is negative with respect to the chamber anode but positive with respect to the cathode voltage and the bias voltage on the substrate. The apparatus is used to manufacture sputter coated articles such as semiconductor wafers. The method provides that the voltage on the central electrode is adjusted to a level which improves the ion flux distribution uniformity on the substrate. The electrode voltage is generally optimized in the range of from -8 volts to -20 volts.

Method of improving ion flux distribution uniformity on a substrate

A magnetron sputtering method and apparatus employing a one-piece annular target having a concave continuously smooth surface with an inwardly facing portion close to and surrounding the outer edge of a stepped wafer provides a sputtering surface with areas facing the differently facing surfaces of the wafer steps. Two concentric erosion zones on the target surface are independently energized at different electrical parameter values by synchronizing the power applied to the single target with switched activation of plasmas overlying the respective target regions which define the erosion zones. The electrical parameters and the geometry are established so as to uniformly coat the differently facing surfaces of the stepped wafer. During part of the duty cycle during which each target region is energized, parameters may be measured. Such parameters may be those which vary with changes in geometry as for example may be due to target erosion. The operation of different target regions, such as the duty cycles or power levels for such regions, may be separately varied in response to the measurements or otherwise, to maintain uniform substrate coating as the target erodes. The target is thicker under the outer region and has an annular pole piece embedded to reduce the space separating the target erosion regions, and includes means to cool the target and reinforce it against thermal expansion.

Method and apparatus for sputter coating stepped wafers

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. 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. An elongated inner pole piece has outwardly extending portions near each end to improve uniformity of a trapping magnetic field between the inner pole piece and a rectangular annular outer pole piece.

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Sloatsburg, NY, United States of America

Robert G Hieronymi