Materials Research Corporation

Tokyo Electron Limited

Tokyo Electron Limited of Ibs Broadcast Center

Israel Wagner

Steven D Hurwitt

Robert G Hieronymi

Charles Van Nutt

Tugrul Yasar

Ira Reiss

Richard C Edwards

Subhadra Gupta

Rajendrapura Seetharamaiya Krishnaswamy

Donald A Messina

Thickness uniformity of films sputtered from a target onto a series of substrates is maintained as the target surface shape changes due to the consumption of the target. The eroded condition of the target is sensed by directly measuring the position of a point on the target surface, by measuring power consumption of the target, by measuring deposition from the surface of the target or by some other means. A controller responds to the measurement by moving a substrate holder to determine an amount to change the distance between the substrate and the target, usually by moving the substrate closer to the target, by an amount necessary to maintain uniformity of the coatings on the wafers being processed. A servo or stepper motor responds to a signal from the controller to move the substrate holder in accordance with the determined amount of distance change required. The adjustment is made following the coating of wafers at various times over the life of the target.

Method and apparatus for sputter coating with variable target to substrate spacing

Method and apparatus for forming the longitudinal edges of stacks of razor blades by conveying the stacks of razor blades along a conveying path in a vacuum chamber past material deposition and material etching stations. The material etching stations are mounted in the sides of the vacuum chamber to be directed generally toward the edge sides of the edges of the razor blades. In another embodiment, stacks of razor blades are mounted on opposite sides of a rotating pallet and material deposition and etching stations are mounted in both side walls of the vacuum chamber. A DC or RF bias is applied to the stacks of razor blades by capacitively coupling the RF bias or conducting by electrical contacts a DC or RF bias to a central portion of the rotating pallet.

Process equipment with simultaneous or sequential deposition and etching

The aperture plate of the present invention is positioned between a sputter target and a substrate to be coated with a film of target material. The substantially non-collimating plate contains a plurality of apertures which intercept a percentage of the sputter particles while allowing other sputter particles to be deposited upon the substrate to form the film. The rate of deposition achieved by the aperture plate is less than the rate of sputtering so that the target may be sputtered at a sufficiently higher rate to reduce the formation of a reactant film on the sputter target while the deposition rate is sufficiently low to allow adequate reaction between a reactive gas and sputter particles to form the desired reactant film on the substrate. In accordance with another aspect of the invention, the apertures of the plate have different aspect ratios or different densities in various different regions of the plate to achieve various different deposition rates in different areas of the substrate. The aspect ratios of the apertures may be selectively varied to achieve a more uniform film thickness or a film of selectively varied thicknesses. The various aspect ratios are achieved by selectively varying a cross-sectional area and/or depth of the apertures in the plate.

Stationary aperture plate for reactive sputter deposition

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 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 magnetron sputtering apparatus and method, in which the ion flux bombarding the substrate is made uniform. Countermagnet means are chosen and positioned such that the vertical components of the countermagnet field are of opposite direction and equal magnitude to the vertical components of the cathode magnet in the vicinity of the substrate. Thus, the cathode magnetic field lines become substantially flat in the vicinity of the substrate and do not cause the ion flux to be distributed on the substrate surface in a non-uniform manner. Measurement of ion current density on the substrate surface during operation of the invention reveals that the invention provides substantially constant flux at all points on the substrate surface.

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Israel Wagner