Strasbaugh

Other

Alan Strasbaugh

Salman Moudrek Kassir

A wafer carrier with a back pressure applicator system adapted to provide high resolution back pressure control. A plurality of millimeter scale distensible elements are disposed between the wafer carrier pressure plate and a process wafer, and selectively distended to provide excess backpressure to select small areas of a wafer known to exhibit resistance to removal vis-&#xe0;-vis the surrounding wafer surface. Distensible elements may be in the form of expandable pneumatic chambers or electro-mechanical elements such as solenoids, shape memory elements, electrostatic plates, etc.

Back pressure control system for CMP and wafer polishing

A method of backgrinding wafers wherein backgrinding tape or a pad is applied to the chuck and not to the wafers. The backgrinding tape or pad is left on the chuck as each wafer is sequentially placed on the tape or pad, background, rinsed on the backside, removed from the tape and then cleaned on the front side and backside. A tool for applying tape to a chuck, as described herein, facilitates this method.

Method of backgrinding wafers while leaving backgrinding tape on a chuck

A wafer carrier with a back pressure applicator system adapted to provide high resolution back pressure control. A plurality of millimeter scale distensible elements are disposed between the wafer carrier pressure plate and a process wafer, and selectively distended to provide excess backpressure to select small areas of a wafer known to exhibit resistance to removal vis-&#xe1;-vis the surrounding wafer surface. Distensible elements may be in the form of expandable pneumatic chambers or electro-mechanical elements such as solenoids, shape memory elements, electrostatic plates, etc.

A method of backgrinding wafers wherein backgrinding tape or a pad is applied to the chuck and not to the wafers. The backgrinding tape or pad is left on the chuck as each wafer is sequentially placed on the tape or pad, background, and then removed from the tape. A tool for applying tape to a chuck, as described herein, facilitates this method.

An optical sensor that includes a light source and a detector is located within a cavity in a polishing pad so as to face the surface that is being polished. Light from the light source is reflected from the surface being polished and the detector detects the reflected light. The electrical signal produced by the detector is conducted to a hub located at the central aperture of the polishing pad. The disposable polishing pad is removably connected, both mechanically and electrically to the hub. The hub contains electronic circuitry that is concerned with supplying power to the optical sensor and with transmitting the electrical signal to a non-rotating station. Several techniques are described for accomplishing these tasks. The system permits continuous monitoring of an optical characteristic of a surface that is being polished, even while the polishing machine is in operation, and permits the end point of the polishing process to be determined.

Method for making a polishing pad with built-in optical sensor

A tool and method for applying an insert to the face of a chuck so that holes in the insert register with holes in the chuck, includes a removable vacuum chamber that is brought into sealing engagement with the chuck and that is indexed with respect to the chuck by means of locating pins. The removable vacuum chamber includes a stamp on which the insert is mounted and to which the insert is indexed by locating pins. The stamp is advanced until an adhesive surface of the insert contacts the face of the chuck. Thereafter, the vacuum is relieved and the vacuum chamber is removed from the chuck. The tool insures that the holes in the insert register with those in the face of the chuck, and the absence of air within the vacuum chamber prevents air from being trapped between the insert and the face of the chuck.

Method for applying an insert or tape to chucks or wafer carriers used for grinding, polishing, or planarizing wafers

The apparatus is used to remove material uniformly from all regions of a wafer surface that is being polished. This is in contrast to conventional lapping machines which preferentially remove material from the high spots on the surface being polished so as to render the surface planar. The result of the present invention is achieved by providing a downwardly-opening plenum on the underside of a carrier. The opening is covered by a flexible membrane, and when a pressurized fluid is applied to the plenum, the membrane applies a uniform downward pressure across the entire upper surface of a wafer that is being polished. The uniform pressure results in a uniform removal of material all across the wafer. The wafer is typically 680 microns thick and the coating is typically two microns thick. Through use of the apparatus, the thickness of the coating is uniformly reduced to about 0.8 micron while maintaining the uniformity of the coating to within 0.02 micron.

Wafer carrier for film planarization

An apparatus for acquiring, holding, and releasing a wafer includes a soft resilient membrane that covers a horizontal backing plate. The lower face of the backing plate includes a number of recessed areas to which a vacuum can selectively be applied. To acquire a wafer, the wafer is elevated carefully until the upper side of the wafer contacts the lower side of the membrane. Next, a vacuum is applied to the recessed areas which sucks the resilient membrane into the recessed areas so that each recessed area becomes a suction cup that draws the wafer against the membrane. When the vacuum is replaced by ambient pressure, the resiliency of the membrane restores it to its original taut condition thereby releasing the wafer. The same apparatus can be used for uniformly polishing the lower face of the wafer by applying a pressurized fluid to the recessed areas during polishing, which causes the membrane to exert a uniform downward pressure on the wafer.

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San Luis Obispo, CA, United States of America

Alan Strasbaugh