Strasbaugh

Strasbaugh, a California Corporation

Salman Moudrek Kassir

Thomas A Walsh

Alan Strasbaugh

Larry A Spiegel

The present embodiments provide methods, systems and apparatuses for use in grinding work pieces, such as wafers. Some embodiments provide methods that position a grind spindle to contact a first grinding spindle to a face of a work piece, remove a portion of the face, and control the removing of the portion of the face according to a control algorithm. This control algorithm can comprise determining a force applied to the work piece during the removing of the portion of the face, adjusting a feed rate of the first grind spindle when the force applied to the work piece has a predefined relationship with a first threshold level; and dressing a portion of the first grinding portion when the force applied to the work piece has a predefined relationship with a second threshold level that is greater than the first threshold.

Grinding apparatus and method

A method of relieving surface stress on a thin wafer by removing a small portion of the wafer substrate, the substrate being removed by applying a warm solution of KOH to the backside of the wafer while the wafer spins. The wafer may be supported on a rotatable platform adapted to direct the flow of chilled, deionized water underneath the device side of the wafer. The chilled water supports the wafer and protects the devices built-up on the wafer from the corrosive effects of KOH and from thermal damage.

Chuck for supporting wafers with a fluid

A grinding assembly for shaping work pieces that includes one or more grind spindles. Each of the grind spindles include two independent grinding wheels driven by a single spindle drive. The grind spindles translate horizontally to perform both edge and face grinding with a single grind spindle. A non-contact position sensor in a work spindle measures work spindle displacement during grinding and provides feedback to the grind spindle to regulate the force imparted on the work piece by the grind spindle. In variations, an abrasive wheel disposed radially with respect to an axis of spindle rotation is utilized to perform edge grinding of the work piece. In other variations cleaning, polishing and grinding are carried out in a single grinding assembly. In yet other variations, a wheel dressing apparatus is utilized to dress the wheel when one or more forces to maintain productivity of the grind wheel exceed a threhold.

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

The present invention provides an apparatus and method for protecting a work piece during surface processing. The apparatus employs a protective material to protect a wafer during backside grinding. The apparatus can further include a vacuum chuck that allows the passage of a vacuum signal, a frame holding the protective material, a frame holder to hold the frame, and a fastening arrangement to fasten the frame holder to the chuck adjacent a support surface. The method provided by the invention can include providing a vacuum chuck, placing a protective material in contact with the chuck, placing a wafer in contact with the protective material, applying a vacuum signal securing the wafer with the chuck, and grinding the backside surface of the wafer.

Protection of work piece during surface processing

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.

A method of relieving surface stress on a thin wafer by removing a small portion of the wafer substrate, the substrate being removed by applying a solution of KOH to the wafer while the wafer spins.

Method of spin etching wafers with an alkali solution

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

In a type of end effector used for handling wafers in the semiconductor industry, the wafer is acquired by lowering the end effector until it almost touches the upper side of the wafer and then applying suction to lift the water into contact with a wafer contacting surface on the underside of the end effector. Release of the wafer is accomplished by relieving the suction or replacing it with a small overpressure. Wet thin wafers do not reliably release; the liquid spreads into a thin film between the upper side of the wafer and the wafer contacting surface, and the surface tension of this film causes the thin wet wafer to adhere to the wafer contacting surface. This problem is solved by affixing a sheet of a porous resilient material, such as open cell MYLAR&reg;, to the wafer contacting surface.

Apparatus and method for reliably releasing wet, thin wafers

A method and apparatus for planarizing silicon wafers initially having wavy surfaces, such as might result from having been cut from a boule by means of a wire saw. A vacuum is applied to one side of a porous ceramic plate, and a perforated resilient pad is applied to the opposite side of the porous ceramic plate. The resilient pad is affixed to the ceramic plate by a peelable adhesive, and the vacuum extends through the perforations of the resilient pad to permit a wafer to be mounted on the exposed side of the resilient pad. The perforations in the resilient pad are distributed uniformally across the wafer, so that the atmospheric pressure pushing the wafer against the resilient pad is also uniform across the wafer. However, the wafer is not deformed while it is held in place for grinding. Because the wafer is not held in an elastically deformed condition while it is ground, the wafer has no tendency to spring back to its original wavy shape. Once one side of the wafer has been planarized, conventional methods can be employed to planarize the second surface of the wafer and to make uniform its thickness. The method is fully compatible with existing grinding machines and, except for the insertion of the resilient pad, requires no departure from the standard grinding techniques.

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Paso Robles, CA, United States of America

Salman Moudrek Kassir