Varian Associates, Inc.

Other

Tokyo Electron Limited

Frederick T Turner

Martin A Hutchinson

Lawrence T Lamont, Jr

R Howard Shaw

David J Harra

Kenneth E Anderson

Phillip B Nicholson

Adolphus E McClanahan

Robert F Foster

Glyn J Reynolds

Donald R Boys

Robert Clark Rowan, Jr

Michael James Lombardi

Walter E Graves, Jr

Lawrence R Stark

One or more chambers of a multi-chamber vacuum processing apparatus are provided with a high gas flow conductance path to an exhaust volume of the apparatus that is maintained at high vacuum with a high vacuum pump. Separate pumps for the one or more chambers are made unnecessary by providing such chambers with a protective deposition shield or shield set that is configured to substantially protect walls of the chamber and the gas flow conductance path from deposition and to partially impede the gas flow from the chamber through the gas flow conductance path to the exhaust volume so that the chamber can be operated at a higher pressure than that of the exhaust volume and the chambers can be operated at different pressures and without cross-contamination. Preferably, a nested set of chamber shields is used. A controller is programmed to control the processing of wafers in the chambers by controlling the supply of process gas into the chambers.

Vacuum-processing chamber-shield and multi-chamber pumping method

An apparatus for releasably clamping a substrate to a support platform, or other support means, at a face of the substrate is described. In one embodiment, a retractable clamp holds a substrate near its edges on a support platform when the clamp is in its fully extended position. One or more leaf springs are mounted to the clamp and apply force to the substrate at respective points in the event the substrate adheres to the clamp, thereby releasing the substrate from the clamp. In a preferred embodiment of the present invention, one or more activators are positioned in cooperative relationship to the leaf springs to cause the leaf springs to retract into recesses in the clamp when the clamp is extended against the substrate. In their retracted position, the leaf springs do not contact the substrate so as to minimize the generation of particle contamination and the chance of the release leaf springs themselves adhering to the substrate.

Clamp with wafer release for semiconductor wafer processing equipment

An apparatus for releasably clamping a substrate to a support platform, or other support system, at a face of the substrate is described. In one embodiment, a retractable clamp holds a substrate near its edges on a support platform when the clamp is in its fully extended position. One or more leaf springs are mounted to the clamp and apply force to the substrate at respective points in the event the substrate adheres to the clamp, thereby releasing the substrate from the clamp. In a preferred embodiment of the present invention, one or more activators are positioned in cooperative relationship to the leaf springs to cause the leaf springs to retract into recesses in the clamp when the clamp is extended against the substrate. In their retracted position, the leaf springs do not contact the substrate so as to minimize the generation of particle contamination and the chance of the release leaf springs themselves adhering to the substrate.

Semiconductor wafers having patterns of steps and grooves defining microcircuit elements thereon are coated with metallic film by supporting the wafers individually adjacent a respective ring-shaped sputtering source in stationary relationship thereto. To effectuate such individual wafer processing on a continuous basis and preserve the evacuated argon environment, a vacuum chamber sputter coating apparatus is provided which has a number of work stations therein, at least one of which includes said ring-shaped sputtering source. Also included is a load lock, and an intermittently rotting vertical plate-like wafer carrier means therewithin positioned closely adjacent the chamber entrance, and carrying wafers in turn from the load lock to the work stations. The carrier includes apertures each accepting a wafer therewithin in an upright position, with the wafers edgewise resiliently supported by clip means, without the use of any externally-originating supports such as platens. Both surfaces of wafer can be accessed by processing equipment, for example, heating or cooling means at some of the work stations. Only a few wafers inside the chamber are at risk at any one time, and introduction of contaminants, debris, as well as disturbances to the chamber environment minimized.

Wafer coating system

Semiconductor wafers having patterns of steps and grooves defining microcircuit elements thereon are coated with metallic film by supporting the wafers individually adjacent a respective ring-shaped sputtering source in stationary relationship thereto. To effectuate such individual wafer processing on a continuous basis and preserve the evacuated argon environment, a vacuum chamber sputter coating apparatus is provided which has a number of work stations therein, at least one of which includes said ring-shaped sputtering source. Also included is a load lock; and an intermittently rotating vertical plate-like wafer carrier means therewithin positioned closely adjacent the chamber entrance, and carrying wafers in turn from the load lock to the work stations. The carrier includes apertures each accepting a wafer therewithin in an upright position, with the wafers edgewise resiliently supported by clip means, without the use of any externally-originating supports such as platens. Both surfaces of the wafer can be accessed by processing equipment, for example, heating or cooling means at some of the work stations. Only a few wafers inside the chamber are at risk at any one time, and introduction of contaminants, debris, as well as disturbances to the chamber environment are minimized.

A modular wafer processing machine is provided which is based on interconnected handling units having wafer handling arms. Each unit can pass a wafer to another unit in the same vacuum environment to a processing module.

Modular wafer transport and processing system

Semiconductor wafers having patterns of steps and grooves defining microcircuit elements thereon are coated with metallic film by supporting the wafers individually adjacent a respective ring-shaped sputtering source in stationary relationship thereto. Within a short deposition time of approximately one minute, good uniformity of deposition across the main wafer plane is obtained by maintaining source-to-wafer spacing less than the diameter of the source, and an effective source diameter (D.sub.s) larger than the diameter of wafer (D.sub.w) with the coating being performed within an argon environment of 2 to 20 microns pressure. Good step coverage across all surfaces of steps and grooves is likewise obtained, and is further enhanced by confining the source-to-wafer spacing ranges to certain values within about 0.4 D.sub.s to 0.9 D.sub.s and the wafer diameter to certain values up to about 0.7 D.sub.s. To effectuate such individual wafer processing on a continuous basis and preserve the evacuated argon environment, a vacuum chamber sputter coating apparatus is provided which has a number of work stations therein, at least one of which includes said ring-shaped sputtering source. Also included is a load lock; and an intermittently rotating vertical plate-like wafer carrier means therewithin positioned closely adjacent the chamber entrance, and carrying wafers in turn from the load lock to the work stations. The carrier includes apertures each accepting a wafer therewithin in an upright position, with the wafers edgewise resiliently supported by clip means, without the use of any externally-originating supports such as platens. A closure member within the chamber is movable against the plate opposite the chamber entrance to close off the plate aperture from the chamber environment during loading and unloading of a wafer, and a door is provided to close the chamber opening and thus complete a thin low-volume load lock. The door is also provided with vacuum means to grasp a wafer presented vertically by a blade-like elevator which cooperates with a cassette and conveyor moving the cassette along a horizontal path below the chamber entrance. The cassette holds wafers vertically, and the blade passes therethrough to lift individual wafers edgewise to the door vacuum means. Closure of the door inserts the wafer into the clip means within the carrier and chamber, and the reverse operation extracts a wafer previously coated at a sputtering work station. Both surfaces of the wafer can be accessed by processing equipment, for example, heating or cooling means at some of the work stations. Only a few wafers inside the chamber are at risk at any one time, and introduction of contaminants, debris, as well as disturbances to the chamber environment are minimized.

A method of sputter depositing a desired film thickness profile on a substrate is accomplished by depositing material onto a substrate at spaced apart coating stations whereby a substrate at any of said stations is not coated by the sputter coating action at any of the other sputter stations. The substrate is held stationary during complete sputtering at each station. A blocking shield is placed in fixed position between the substrate and the sputter coating source at one or more of the stations. The duration of sputter coating time at one station may be different than at another station.

Blocking shield and method for contouring the thickness of sputter

Apparatus for compensating for asymmetric signatures in semiconductor processes. An asymmetric thickness profile is obtained in a sputter coating system by using a shield placed in an asymmetric position with respect to the center of a symmetric sputtering system such as a circularly symmetric sputtering system. A sputter coated layer is obtained which has the asymmetric character of the shield and its placement. When the substrate is placed in subsequent equipment having asymmetric etch characteristics, the resultant film has a uniform thickness or a known contour.

Apparatus for asymmetrically contouring the thickness of sputter coated

The arbitrary contouring of thickness of a sputter-deposited film is made possible by a blocking means having a primary blocking shield and an ancillary blocking shield. The primary blocking shield intercepts atoms sputtered directly from the cathode target by line-of-sight transport. The ancillary blocking shield extends downwardly from the side of the primary blocking shield which is placed closest to the substrate. The ancillary blocking shield intercepts atoms sputtered from the cathode which by intervening gas collisions have been redirected to travel underneath the primary blocking shield. Precise tailoring of the thickness profile of the coating on the substrate is thereby provided and the quality of the composite film is maintained. The method for contouring the thickness of sputter coated layers comprises sputter coating portions of the film at successive stations. By employing the improved blocking shield at selected stations, the film in the aggregate may have the desired thickness contour.

Sputter system incorporating an improved blocking shield for contouring

An RF etch table has a biased extension member positioned adjacent its periphery. The extension member is electrically conductive, but is insulated from other conductive members in the system. The extension member is positioned with respect to the periphery of the table in a manner such that the boundary of the plasma induced above the etch table is continued beyond the periphery of the etch table, thereby eliminating the focusing of ions onto the edges of an item being etched on the table. The potential impressed upon the extension member produces a dark space above its surface having a sufficient height so that the horizontal configuration of the sheath above the etch table is continued beyond its edges. More uniform etching is accomplished.

Radio frequency etch table with biased extension member

Relatively wide workpieces, such as auto grilles, are rapidly conveyed into and from a vacuum processing chamber provided with entry and exit air locks and vacuum isolation valves, in which thin metallic coatings are deposited uniformly over workpiece surfaces. The gate member of the valve is supported for sliding vertical movement, as well as limited outward and inward movement for sealing the chamber opening, at the protruding ends of an elongated member backing the gate. Air cylinders act directly on these ends to close the gate. A linkage and air cylinder above the gate vertically propels the gate. The processing chamber is provided with several side by side arrays of sputtering sources with circular cathodes, the workpieces moving thereunder at a steady rate orthogonally to the arrays. The spacings of each source relative to the other in each array, the workpiece to source distance, and the degree of outboard placement of the outer sources relative to the workpiece edges are defined to provide both even coatings on horizontal workpiece surfaces, as well as on the vertical surfaces. A compact conveyor system with space-saving corner modules is coordinated with the valve action to maintain an even steady flow through the evacuated processing chamber for optimum coating.

Sputter-coating system, and vaccuum valve, transport, and sputter source

A sputtering system utilizes a computer to monitor the power dissipation in the sputtering source and to accumulate the history of usage of the particular sputtering target. Desired deposition rate information is input to the computer, which establishes and maintains the desired rate and controls the plasma discharge to compensate for aging and deterioration of the target. End of useful target life is determined by the computer from objective criteria to trigger appropriate actions.

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Sunnyvale, CA, United States of America

Frederick T Turner