Abstract: An implanter provides two-dimensional scanning of a substrate relative to an implant beam so that the beam draws a raster of scan lines on the substrate. The beam current is measured at turnaround points off the substrate and the current value is used to control the subsequent fast scan speed so as to compensate for the effect of any variation in beam current on dose uniformity in the slow scan direction. The scanning may produce a raster of non-intersecting uniformly spaced parallel scan lines and the spacing between the lines is selected to ensure appropriate dose uniformity.

Abstract: Semiconductor processing apparatus is disclosed which provides for movement of a scanning arm 60 of a substrate or wafer holder 180, in at least two generally orthogonal directions (so-called X-Y scanning). Scanning in a first direction is longitudinally through an aperture 55 in a vacuum chamber wall. The arm 60 is reciprocated by one or more linear motors 90A, 90B. The arm 60 is supported relative to a slide 100 using gimballed air bearings so as to provide cantilever support for the arm relative to the slide 100. A compliant feedthrough 130 into the vacuum chamber for the arm 60 then acts as a vacuum seal and guide but does not itself need to provide bearing support. A Faraday 450 is attached to the arm 60 adjacent the substrate holder 180 to allow beam profiling to be carried out both prior to and during implant.

Abstract: This invention relates to an ion beam monitoring arrangement for use in an ion implanter where it is desirable to monitor the flux and/or a cross-sectional profile of the ion beam used for implantation. It is often desirable to measure the flux and/or cross-sectional profile of an ion beam in an ion implanter in order to improve control of ion implantation of a semiconductor wafer or similar. The present invention describes adapting the wafer holder to allow such beam profiling to be performed. The substrate holder may be used progressively to occlude the ion beam from a downstream flux monitor or a flux monitor may be located on the wafer holder that is provided with a slit entrance aperture.

Abstract: This invention relates to a method of implanting ions in a substrate using an ion beam where instabilities in the ion beam may be present and to an ion implanter for use with such a method. This invention also relates to an ion source for generating an ion beam that can be switched off rapidly. In essence, the invention provides a method of implanting ions comprising switching off the ion beam when an instability has been detected whilst continuing motion of the substrate relative to the ion beam to leave an unimplanted portion of a scan line across the substrate, establishing a stable ion beam once more and finishing the scan line by implanting the unimplanted portion of the path.

Abstract: An implanter provides two-dimensional scanning of a substrate relative to an implant beam so that the beam draws a raster of scan lines on the substrate. The beam current is measured at turnaround points off the substrate and the current value is used to control the subsequent fast scan speed so as to compensate for the effect of any variation in beam current on dose uniformity in the slow scan direction. The scanning may produce a raster of non-intersecting uniformly spaced parallel scan lines and the spacing between the lines is selected to ensure appropriate dose uniformity.

Abstract: An indirectly heated button cathode for use in the ion source of an ion implanter has a button member formed of a slug piece mounted in a collar piece. The slug piece is thermally insulated from the collar piece to enable it to operate at a higher temperature so that electron emission is enhanced and concentrated over the surface of the slug piece. The slug piece and collar piece can be both of tungsten. Instead the slug piece may be of tantalum to provide a lower thermionic work function. The resultant concentrated plasma in the ion source is effective to enhance the production of higher charge state ions, particularly P+++ for subsequent acceleration for high energy implantation.

Abstract: A force compensator is provided for a semiconductor processing apparatus having a moving member, in order to compensate for a fixed force on the moving member, such as gravity or atmospheric pressure. A vacuum and piston combination is connected between the movable member and a reaction point. One side of the piston is open to atmosphere and the other side defines an enclosed region which is evacuated. The cylinder is evacuated to a pressure which does not exceed 10% of ambient pressure during operation of the device, so that pressure changes in the low pressure region have minimal effect on the compensation force during movement of the movable member over its displacement range.

Abstract: An implanter provides two-dimensional scanning of a substrate relative to an implant beam so that the beam draws a raster of scan lines on the substrate. The beam current is measured at turnaround points off the substrate and the current value is used to control the subsequent fast scan speed so as to compensate for the effect of any variation in beam current on dose uniformity in the slow scan direction. The scanning may produce a raster of non-intersecting uniformly spaced parallel scan lines and the spacing between the lines is selected to ensure appropriate dose uniformity.

Abstract: An indirectly heated button cathode for use in the ion source of an ion implanter has a button member formed of a slug piece mounted in a collar piece. The slug piece is thermally insulated from the collar piece to enable it to operate at a higher temperature so that electron emission is enhanced and concentrated over the surface of the slug piece. The slug piece and collar piece can be both of tungsten. Instead the slug piece may be of tantalum to provide a lower thermionic work function. The resultant concentrated plasma in the ion source is effective to enhance the production of higher charge state ions, particularly P+++ for subsequent acceleration for high energy implantation.

Abstract: An implanter provides two-dimensional scanning of a substrate relative to an implant beam so that the beam draws a raster of scan lines on the substrate. The beam current is measured at turnaround points off the substrate and the current value is used to control the subsequent fast scan speed so as to compensate for the effect of any variation in beam current on dose uniformity in the slow scan direction. The scanning may produce a raster of non-intersecting uniformly spaced parallel scan lines and the spacing between the lines is selected to ensure appropriate dose uniformity.

Abstract: A semiconductor substrate support apparatus comprises a support chuck having at least one chuck manifold extending through the support chuck, and a rotatable shaft coupled to the support chuck. The shaft has at least one shaft conduit disposed therein and extends through the support chuck. A housing circumscribes the shaft and has a housing conduit adapted for connection to a gas source. A plurality of seals are disposed between the shaft and the housing and thereby define a radial passageway between the at least one shaft conduit and the housing conduit for providing a backside gas to a backside of a wafer disposed on the rotating support chuck.

Abstract: Semiconductor processing apparatus is disclosed which provides for movement of a scanning arm 60 of a substrate or wafer holder 180, in at least two generally orthogonal directions (so-called X-Y scanning). Scanning in a first direction is longitudinally through an aperture 55 in a vacuum chamber wall. The arm 60 is reciprocated by one or more linear motors 90A, 90B. The arm 60 is supported relative to a slide 100 using gimballed air bearings so as to provide cantilever support for the arm relative to the slide 100. A compliant feedthrough 130 into the vacuum chamber for the arm 60 then acts as a vacuum seal and guide but does not itself need to provide bearing support. A Faraday 450 is attached to the arm 60 adjacent the substrate holder 180 to allow beam profiling to be carried out both prior to and during implant.

Abstract: An indirectly heated button cathode for use in the ion source of an ion implanter has a button member formed of a slug of tantalum mounted in a collar of tungsten. The lower thermionic work function of tantalum causes electron emission to be concentrated over the surface of a tantalum slug. The tantalum slug may be mounted to enable it to operate at a higher temperature compared to the surrounding tungsten collar portion. The resultant concentrated plasma in the ion source is effective to enhance the production of higher charge state ions, particularly P+++ for subsequent acceleration for high energy implantation.

Abstract: A back scattered ion receiver is mounted on the process chamber of an ion implanter to receive beam ions back scattered from a wafer mounted on the wafer holder in the chamber. Minima in the intensity of back scattered ions as the wafer on the holder is moved relative to the beam direction, can be used to obtain an accurate calibration of the true beam direction. Beam direction error can then be compensated for when operating holder tilt and twist mechanisms so as to bring a process wafer accurately into the required orientation relative to the true beam. If the crystallographic alignment and orientation of process wafers has been precharacterised, this data can be used to control the wafer holder to align process wafers crystallographically to the process beam.

Abstract: A vacuum bearing structure comprises a combination of a planar gas bearing with a differentially-pumped vacuum seal. The bearing surface and the vacuum seal surfaces are formed of a porous material divided into a first outer region through which bearing gas can percolate to provide support and an inner second region providing the vacuum seal. An exhaust groove separates the two regions so that bearing gas can flow to atmosphere. The resulting structure can operate at a lower fly height to reduce loading on the differentially-pumped vacuum seal. The structure is particularly useful for motion feedthroughs into vacuum processes such as ion implantation.

Abstract: An ion electrode extraction assembly comprising an ion source 20 and at least one electrode 50 having a gap through which a beam of extracted ions passes in use. An electrode manipulator assembly 55 is provided to move the electrode so as to vary the width of the gap transversely to the ion beam, move the electrode transversely to the ion beam, and move the electrode in the direction of the ion beam. The three degrees of movement being carried out independently of one another.

Abstract: A semiconductor substrate support apparatus comprises a support chuck having at least one chuck manifold extending through the support chuck, and a rotatable shaft coupled to the support chuck. The shaft has at least one shaft conduit disposed therein and extends through the support chuck. A housing circumscribes the shaft and has a housing conduit adapted for connection to a gas source. A plurality of seals are disposed between the shaft and the housing and thereby define a radial passageway between the at least one shaft conduit and the housing conduit for providing a backside gas to a backside of a wafer disposed on the rotating support chuck.

Abstract: An apparatus used to control a workpiece inside a vacuum chamber. The workpiece is supported on a workpiece holder in the vacuum chamber. The workpiece is isolated from the atmosphere outside of the vacuum chamber by differentially pumped vacuum seals and an integral air bearing support. The differentially pumped vacuum seals and integral air bearing support allow for multiple independent motions to be transmitted to the workpiece supported by the workpiece holder. The workpiece holder motions provided are (1) rotation about the X axis, (2) translation back and forth along the Y direction of an X-Y plane on the surface of the workpiece holder, and (3) rotation of the workpiece in the X-Y plane about its Z axis. Concentric seals, oval for the translation motion and circular for the rotational motion, are differentially pumped through common ports to provide successively decreasing pressure and gas flow in order to reduce the gas load into the vacuum vessel to a negligible rate.

Abstract: A wafer holder assembly includes first and second main structural members from which first and second wafer-holding arms extend. The first arm is secured to the main structural members by a graphite distal retaining member. The second arm is pivotally biased to a wafer-hold position by a graphite bias member. This arrangement provides a conductive path from the wafer to the assembly for inhibiting electrical discharges from the wafer during the ion implantation process. The assembly can further include additional graphite retaining members for maintaining the structural integrity of the assembly during the extreme conditions associated with SIMOX wafer processing without the need for potentially wafer-contaminating adhesives and conventional fasteners. The wafer-contacting pins at the distal end of the arms can be formed from silicon. The silicon pins can be coated with titanium nitride to enhance electrical contact with the wafer and to provide an abrasion resistant surface.

Abstract: A force compensator is provided for a semiconductor processing apparatus having a moving member, in order to compensate for a fixed force on the moving member, such as gravity or atmospheric pressure. A vacuum and piston combination is connected between the movable member and a reaction point. One side of the piston is open to atmosphere and the other side defines an enclosed region which is evacuated. The cylinder is evacuated to a pressure which does not exceed 10% of ambient pressure during operation of the device, so that pressure changes in the low pressure region have minimal effect on the compensation force during movement of the movable member over its displacement range.