International Business Machines Corporation

Alfred Mack

Brian C O'Neill

Michael F McAllister

Javathu K Hassan

Charles A Gaston

Richard G Christensen

Alan D Wilson

Charles H Locke

Warren J Pinckney

Michael R Wojtaszek

Karl W Beumer

Fred L Penzetta

A wafer transfer apparatus used in manufacturing high density semiconductor products is disclosed which includes at least three movable arms for supporting a wafer from below thereby preventing contact with the active surface of the wafer. A mechanism for moving the arms into and out of its wafer supporting position is diposed, in part, above the wafer when a wafer is supported thereby. The portions of the actuator mechanism disposed above the wafer are constructed in a way such that no sliding contact occurs between elements thereof. Sliding contact between elements disposed above a wafer has proved to produce microscopic particles which can fall onto the active surface of the wafer thereby contaminating the circuits contained thereon. As sliding contact is avoided by the apparatus of the present invention, contamination particles produced within the wafer transfer apparatus is substantially reduced, if not entirely eliminated.

Wafer transfer apparatus

A system of interconnection of a set of coaxial cables to a device, such as a testing apparatus for an integrated circuit chip, includes an apertured plate of electrically conducting material which positions each of the connectors in registration with corresponding terminals of the device. Each connector includes a spring-loaded probe insulated from a housing of the connector and making connection between an inner conductor of a coaxial cable and the corresponding terminal of the device. Also included are signal-return spring-loaded probes mounted in the plate and electrically connected thereby to the other conductors of the coaxial cables to provide signal-return paths with corresponding terminals of the device. In alternative embodiments, a simpler connection is fashioned by use of a single connector and a single signal-return probe extending from a shoulder of the housing of the connector. Also, a pair of cables can be joined by use of a cylindrical sleeve enveloping a pair of opposed connectors and making electrical contact with the housings thereof.

Coaxial converter with resilient terminal

A high precision, high throughput submicrometer workpiece positioning system, particularly useful as a workpiece positioning means in electron beam lithography tools. The positioning system increases mechanical stability by essentially eliminating mechanical hysteresis, which allows state of the art electron beam lithography systems to provide the repeatable, accurate and dense circuit patterns that modern semiconductor trends demand. The positioning system in preferred form comprises a movable positioning table, a workpiece supporting superstructure which is elastically joined to the movable positioning table by three geometrically distinct kinematic support means and a two-stage coupling means which mounts a workpiece (i.e., semiconductor mask or wafer) to the workpiece supporting superstructure. A laser interferometer locating-positioning system is utilized to position the workpiece. The interferometer mirrors are integral with the workpiece supporting superstructure. The coupling means mounts a workpiece to the workpiece supporting superstructure with a minimum of mechanical distortion. Three two-stage coupling means are utilized in preferred form. The first stage is removable from the positioning, and allows for workpiece loading and unloading outside of the positioning system. The removable stage comprises an integral unit which includes two opposing arms with large radii spherical ends and a tab member. The spherical end center lines are collinear, providing for vertical clamping of the workpiece. The second stage is stationary and integral with the workpiece supporting superstructure. The stationary stage comprises two opposing arms with large radii spherical ends and clamps the tab of the removable stage by vertical clamping.

Workpiece mounting and clamping system having submicron positioning

A coaxial line as a rigid probe interposer is particularly useful for connecting an electrical tester to a high speed integrated circuit utilizes two coaxial dielectrics for spacing a center conductor from an outer conductor in the form of a holed metallic body. The line center conductor is initially coated with a first dielectric. The dielectric coated center conductor is thereafter positioned in an oversized hole within the conductive body. The annular free space existing between the inside wall of the hole and the outer circumference of the first dielectric is filled as by capillary action, with a second, liquid dielectric which flows into the fissures and cracks within the first dielectric prior to curing.

Method of making a hybrid dielectric probe interposer

An elevator drive shaft is air pressure counter-balanced and dampened under varying load and system pressure conditions by applying required air pressure to an appropriate side of a piston moving with the drive shaft in an electron beam semiconductor wafer writing apparatus vacuum chamber. Air pressure counterbalancing load forces minimize the actuating forces required to drive the elevator, substantially minimizing vibratory shock and distortion to the electron beam writing system and increasing speed of wafer movement. This permits electron beam writing on one wafer simultaneously with a load/unload operation of a second semiconductor wafer. The counter-balancing load forces also minimize the probability of accidental damage to the system or semiconductor wafers due to uncontrolled high forces or upon mechanical impact between moving and fixed parts, during apparatus malfunction.

Light actuating force elevator drive mechanism

An electron beam vacuum chamber is provided with an elevator mechanism within the chamber including a platform closing off an opening within a horizontal vacuum chamber wall and separating the vacuum chamber from an overlying antechamber partially defined by a vertically displaceable lid overlying the opening and moving towards and away from the opening. Resilient peripheral seals are fixed to the lid facing the chamber wall and the elevator platform. A coil spring partially compressible upon contact with the first peripheral seal carried by the lid with the face of the vacuum chamber wall forms a first mechanical override and an annular spring metal diaphragm fixedly mounted about its outer peripheral edge to the vacuum chamber adjacent the opening has its inner peripheral edge freely flexible and is contacted by the resilient peripheral seal of the platform to form a second mechanical override.

Low shock transmissive antechamber seal mechanisms for vacuum chamber

A semiconductor wafer, which has chips formed thereon, is moved from a class 100 environment into a vacuum chamber in which pattern writing is performed on the chips by an electron beam without significantly affecting the vacuum level in the vacuum chamber. The wafer is initially disposed on an elevator, which is within the vacuum chamber, through an opening, which is vacuum sealed by the elevator at this time, in the top wall of the vacuum chamber. A lid is then placed over the opening from the exterior to cooperate with the elevator to form an ante chamber which the wafer disposed therein. The ante chamber, which is purged prior to the lid being placed over the opening, is then reduced to a vacuum of 5 .times. 10.sup..sup.-2 torr. The elevator then lowers the wafer into a horizonal plane in which a transfer mechanism is located to transfer the wafer from the elevator to an X-Y table on which the wafer is mounted for pattern writing of the chips. The transfer mechanism includes an arm, which is indexed 180.degree. during each antivation of an indexing means connected thereto, and gripping means at each end of the arm to simultaneously grasp and release wafers on the elevator and X-Y table to interchange the wafers between the elevator and the table.

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Poughkeepsie, NY, United States of America

Alfred Mack