Patents Assigned to Dorsey Gage, Inc.
  • Patent number: 6268994
    Abstract: An electrostatic chuck is formed by: providing a conductive base member; machining a pattern of ridges in the top surface of the base member; providing through holes in the base member; inserting insulated contact posts into through holes and joining same to the base member in such manner that the contact posts extend above the top surface of the base member; depositing a first insulating layer over the base member top surface, ridges and the contact posts, the thickness of the insulating layer being less than the height of the contact posts above the base member surface; removing the first insulative layer from the top of the contact posts and removing a portion of the contact posts in such manner that the contact posts are flush with the surrounding first insulating layer; depositing a conductive layer over the first insulating layer and the tops of the contact posts, the thickness of the conductive layer being approximately the height of the ridges; grinding the top surface of the base member flat to the p
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: July 31, 2001
    Assignee: Dorsey Gage, Inc.
    Inventors: Joseph Logan, Robert Tompkins, John R. Miller
  • Patent number: 5905626
    Abstract: Electrostatic chucks are disclosed in which a conductive pole piece is provided with a flat top surface, sidewall and a perimeter with radiused corners connecting the top surface to the sidewall. The perimeter and sidewall are coated with a ceramic insulative material covering the radiused corners. The top surface is coated with a ceramic semiconductive material. Then the surfaces of the pole piece not covered by ceramic material are anodized in such a manner that the intersections between anodized pole surfaces and ceramic material are below the pole piece top surfaces.
    Type: Grant
    Filed: April 12, 1998
    Date of Patent: May 18, 1999
    Assignee: Dorsey Gage, Inc.
    Inventors: Joseph Logan, Robert Tompkins
  • Patent number: 5901030
    Abstract: An electrostatic chuck employs thermoelectric cooling technology. The chuck includes a conductive circular base with an upper ring portion forming a first pole piece electrically isolated from an annular portion forming a second pole piece. The upper surface of the pole pieces have a dielectric material formed thereon and together form the electrostatic clamping surface for an article to be held thereon. The backside is provided with an annular recess containing a plurality of thermoelectric devices or modules and intervening spokes. The devices are covered with a heat sink or cooling plate through which a fluid such as water is circulated. A retaining back ring covers the water plate which is secured to the base by bolts. Uniform pressure is applied to the water plate and modules by means of spring washers inserted between back ring and water plate.
    Type: Grant
    Filed: December 2, 1997
    Date of Patent: May 4, 1999
    Assignee: Dorsey Gage, Inc.
    Inventors: Joseph Logan, Robert Tompkins