Varian Associates, Inc.

General Electric Company

R Howard Shaw

Martin A Hutchinson

George L Coad

Frederick T Turner

Lawrence T Lamont, Jr

Charles C Morehouse

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.

An assembly is provided for supporting semiconductor wafers individually within a support while permitting processing of both faces of a wafer as well as facilitating rapid insertion and removal of wafers into the support. Each assembly includes a wire clip having an arcuate tip used to grasp the wafer. The wire clip can be moved in two planes by actuating mechanisms, thereby moving the clip out of the plane of wafer processing and facilitating loading in the wafer processing plane.

Wafer support assembly

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.

An elevator structure is actuated to remove wafers individually out of a storage cassette to an elevated delivery position. The elevator is a lift blade with an arcuate upper end shaped to match the curvature of the wafers, and a groove within this end adapted to match the thickness of a wafer and retain a wafer edgewise. A wafer-holding chuck on a chuck assembly is adapted to receive a wafer from the elevator when the elevator is in the elevated delivery position. The chuck assembly is movable from the delivery position to a remote position where the chuck presents the wafer to a support member. The support member is provided with an aperture and a plurality of deformable wafer-holding clips spaced around the aperture. The chuck assembly includes a pneumatic cylinder capable of contacting a portion of each clip to urge same to an open position. The invention includes an arrangement in which the chuck is mounted on a chuck assembly in the form of a door for sealing an opening in a process chamber.

The system for rotating the transfer plate of a coating system in a vacuum chamber consists of a transfer plate driver assembly on the outside of the chamber at the axis and a transfer plate rotator assembly inside the chamber. The driver assembly consists of a pneumatic actuator for linear motion, a barrel cam which translates the linear motion into rotary motion with high torque at starting and stopping positions, and a rotary feedthrough all in a structural housing. The rotator assembly comprises a central hub with means for supporting the end walls, a transfer plate hub assembly and a ratchet arm connected to the rotary feedthrough. As the pressure plate assembly is drawn back by the ram, it in turn draws back the transfer plate and engages the ratchet arm with the transfer plate hub. The actuator then rotates the transfer plate. The ram then reverses direction, the ratchet arm disengages and is returned to its initial position.

Transfer plate rotation system

A modular radiation detector array which allows improved spatial resolution and facilitates installation and replacement for repair. Each module includes two detachably assembled portions with one portion including a plurality of spaced plates for collimating radiation. The second portion includes a printed circuit board, a semiconductor diode array chip mounted on the printed circuit board, and a plurality of scintillator crystals mounted on the semiconductor chip with each crystal overlying a diode. Signals from the diodes are applied to signal processing means by a cable which is readily connected to and disconnected from the diode array.

Modular radiation detector array and module

A system for the automated handling and transfer of wafers individually and repetitively to and between processing stations and cassettes. A track-like conveyor engages a cassette holding a plurality of wafers in vertically facing alignment, to move same horizontally past a loading station of a processing chamber. A vertically moveable blade passes between the conveyor tracks and through the cassette to engage a wafer edgewise from below and move same upwardly to the processing chamber entrance. Vacuum means mounted to the door of the chamber entrance engages and holds the wafer during insertion into the chamber by closure of the door. Clip means are mounted within the periphery of an aperture of a vertical support plate just within the chamber entrance, to engage edgewise the wafer and support it within the plate aperture while in the processing chamber. The wafer is removed after processing by operating the foregoing apparatus in reverse order. The processing chamber may be a vacuum chamber, and minimal-volume load lock means therefor are advantageously provided by the system with the aid of a sealing member within the chamber compressible against the wafer support plate and chamber wall while the chamber door is open, to seal off the entrance area from the remainder of the chamber. The wafer support plate is moveable within the processing chamber to various wafer processing stations once the door is closed and the sealing member withdrawn.

Wafer transfer system

An assembly is provided for protectively supporting semiconductor wafers individually within a support while permitting processing of both faces of the wafer, as well as facilitating rapid insertion and removal of wafers into the support, and movement of wafers between processing stations. The assembly includes a plate-like support through which is defined an aperture of diameter larger than the wafer, and a plurality of clips mounted within the periphery of the aperture and the plane thereof and resiliently gripping edgewise a wafer inserted into the aperture and supporting same within the plane of the aperture. Each clip extends centrally inwardly of the aperture and terminates in an arcuate portion within which the edge of the wafer is retained, and defines a flat portion generally parallel to the aperture plane. The support assembly is advantageously positioned within a processing chamber, and the support plate preferably includes a plurality of apertures and associated clips, as well as being movable within the chamber to various processing stations. Extendable pins associated with the processing chamber are provided to depress the flat portion of the clips during wafer insertion and removal to obviate any possibility of abrasion. Simple automated equipment is usable to effect wafer insertion and removal, and a thin load lock of small volume is easily defined by sandwiching the support between suitable sealing members.

Growing community of inventors

Palo Alto, CA, United States of America

R Howard Shaw