International Business Machines Corporation

Brian C O'Neill

Alfred Mack

Frank M Tappen

Charles A Gaston

Joseph H Koestner

Alan D Wilson

Charles H Locke

Warren J Pinckney

George Anthony Caccoma

Fred L Penzetta

Karl W Beumer

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

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 batch chip placement system for batch positioning semiconductor chips, or the like, upon a substrate containing an array of chip sites or footprints whose actual position on the substrate deviates from the theoretical or nominal position over successive substrates. The positioning is achieved by first sensing the X and Y offsets of a pair of alignment marks on the substrate from their theoretical or nominal position to determine the .DELTA.X and .DELTA.Y correction factors required to obtain the actual X,Y position of the alignment marks. The actual X,Y position of the alignment marks is used to determine actual X,Y chip position values, .theta. rotation and shrinkage factor corrections required to obtain proper orientation and positioning for batch chip placement.

Batch chip placement system

Growing community of inventors

Millbrook, NY, United States of America

Brian C O'Neill