Disco Corporation

Olympus Optical Company, Ltd.

Kenji Furuta

Ryugo Oba

Yohei Yamashita

Masaaki Sato

Hitoshi Hoshino

Nobuyasu Kitahara

Norio Fukuoka

Nobuo Terui

Sakae Matsuzaki

Kazuo Nakasho

Masahide Yoshida

Kazumi Miyaji

Yihui Lee

Takafumi Ohnishi

Keiji Nomaru

Yoshiaki Yodo

Karl Heinz Priewasser

Yosuke Watanabe

Toshiyuki Yoshikawa

Satoshi Genda

Ken Togashi

Noriko Ito

Kiyoshi Ohsuga

Satoshi Usuda

Yuriko Sato

Noburu Takeda

A wafer dividing method includes forming modified layers which will be starting points of division, integrally attaching an annular frame and the wafer together through a dicing tape, directing the wafer downward and expanding the dicing tape to divide, into individual device chips, the wafer along the modified layers formed along the streets, counting particles scattered at the time of division of the wafer by a particle counter disposed in a dust collection path set directly below the wafer, and determining, on the basis of the number of the particles, whether or not the modified layers have been properly formed, at the time of carrying out the dividing step.

Wafer dividing method and dividing apparatus

A wafer processing method includes an adhesive film bonding step of bonding an adhesive film on a side of a back surface of the wafer, an adhesive film cutting-off step of cutting off at least the adhesive film that is bonded on the side of the back surface of the wafer along streets from the side of the back surface of the wafer, a modified layer forming step of irradiating a laser beam of a wavelength that has transmissivity through the wafer with the laser beam focused inside the wafer, so that modified layers are formed along the streets, respectively, and a dividing step of, after performing the adhesive film cutting-off step and the modified layer forming step, applying an external force to the wafer so that the wafer is divided from the modified layers as starting points.

Wafer processing method

A laser beam applying unit of a laser processing apparatus for processing a wafer includes a laser oscillator for emitting a pulsed laser beam having a wavelength transmittable through the wafer, a beam condenser for converging the pulsed laser beam emitted from the laser oscillator onto the wafer held on a chuck table, a beam splitter assembly disposed between the laser oscillator and the beam condenser, for splitting the pulsed laser beam emitted from the laser oscillator to form at least two converged spots on the wafer that are spaced from each other in X-axis directions, and a mask assembly disposed between the laser oscillator and the beam condenser, for reducing the width of the converged spots on the wafer in Y-axis directions to keep the converged spots on the wafer within the width of the projected dicing lines on the wafer.

Laser processing apparatus

A wafer processing method for processing a wafer with devices formed in regions on a side of a front surface of the wafer, the regions being defined by first scheduled division lines and second scheduled division lines includes a first modified layer forming step and a second modified layer forming step. In the first modified layer forming step, a laser beam is irradiated with its focal point set at a height leveled with a height of a first region located inside the wafer on the side of the front surface of the wafer, whereby first modified layers are formed. In the second modified layer forming step, the laser beam is irradiated with its focal point set at a height leveled with a height of a second region located inside the wafer on a side of a back surface of the wafer, whereby second modified layers are formed.

Disclosed herein is an evaluation jig that is a jig to be used for evaluation of a height position detection unit that detects the height position of a holding surface of a chuck table of a laser processing apparatus. The evaluation jig includes a to-be-irradiated surface which is to be irradiated with a detection laser beam, an actuator that moves the to-be-irradiated surface in a Z-axis direction, a base section that supports the actuator and is mounted on the holding surface of the chuck table, and a control unit that controls movement of the actuator.

Evaluation jig and evaluation method for height position detection unit of laser processing apparatus

The invention relates to a method of processing a substrate. The substrate has on a first surface a device area with a plurality of devices partitioned by a plurality of division lines. A pulsed laser beam is applied to the substrate at least in a plurality of positions along each of the division lines, with a focal point located at a distance from the first surface in the direction from the first surface towards a second, opposite surface, so as to form a plurality of modified regions in the substrate along each of the division lines. The second surface of the substrate is then ground to adjust the substrate thickness. After forming modified regions and/or hole regions in the substrate, a plasma can be applied to the substrate so as to form a plurality of grooves extending along the division lines.

Method of processing a substrate

An electrostatic chuck table for holding a workpiece includes: a plate-shaped base transmittable with respect to a laser beam having a predetermined wavelength allowing the laser beam to be transmitted through the workpiece, the plate-shaped base having a first surface and a second surface opposite the first surface; an electrostatic attraction electrode assembly transmittable with respect to the laser beam having the predetermined wavelength, the electrostatic attraction electrode assembly being formed on the first surface of the base; and a resin layer transmittable with respect to the laser beam having the predetermined wavelength, the resin layer covering the electrode assembly and providing a holding surface for holding the workpiece thereon. The electrostatic chuck table is used in forming a modified layer within the workpiece held on the holding surface with the laser beam that is applied to the workpiece from the side of the second surface of the base.

Electrostatic chuck table

An electrostatic chuck table includes a plate-shaped base portion capable of transmitting a laser beam to be applied to a workpiece and an electrostatic attraction electrode portion capable of transmitting the laser beam. The laser beam has a transmission wavelength to the workpiece. The base portion has a first surface and a second surface opposite to the first surface. The electrode portion is formed on the first surface of the base portion. A method for using the electrostatic chuck table includes a workpiece holding step of applying a voltage to the electrode portion formed on the first surface to thereby electrostatically hold the workpiece on the second surface, and a modified layer forming step of applying the laser beam through the first surface to a predetermined position inside the workpiece held on the second surface to thereby form a modified layer inside the workpiece.

Electrostatic chuck table using method

A wafer processing method for dividing a wafer into individual device chips along division lines is disclosed. The wafer processing method includes a back grinding step of grinding the back side of the wafer in the condition where a protective tape is attached to the front side of the wafer, thereby reducing the thickness of the wafer to a predetermined thickness, and a reinforcing insulation seal mounting step of mounting a reinforcing insulation seal capable of transmitting infrared light on the back side of the wafer. The wafer processing method further includes a modified layer forming step of applying a laser beam along each division line to thereby form a modified layer inside the wafer along each division line and a wafer dividing step of applying an external force to the wafer to thereby divide the wafer into the individual device chips along each division line.

A method of processing a wafer having a device area where a plurality of devices are formed and a peripheral marginal area surrounding the device area on the front side of the wafer is disclosed. The devices are formed in regions defined by division lines. Each device has a plurality of bump electrodes on the front side. A first laser beam is applied through dicing tape from the back side along the boundary between the device area and the peripheral marginal area, with the focal point of the first laser beam set inside the wafer, thereby forming an annular modified layer inside the wafer. A second laser beam is applied through the dicing tape from the back side along each division line with the focal point of the second laser beam set inside the wafer, thereby forming a modified layer inside the wafer along each division line.

In a wafer processing method, the back side of the wafer is ground to reduce the thickness of the wafer to a predetermined thickness. A modified layer is formed by applying a laser beam to the wafer from the back side of the wafer along each division line with the focal point of the laser beam set inside the wafer. The wafer is mounted on a reinforcing sheet having an insulating function on the back side of the wafer and a dicing tape is attached to the reinforcing sheet. The peripheral portion of the dicing tape is supported by an annular frame. The wafer is heated, which also heats the reinforcing sheet, thereby hardening the reinforcing sheet. An external force is applied to the wafer to divide the wafer into individual devices along each division line and to also break the reinforcing sheet along the individual devices.

A wafer processing method of dividing a wafer along a plurality of crossing streets formed on the wafer to obtain individual chips. The wafer processing method includes a modified layer forming step of applying a laser beam having a transmission wavelength to the wafer along each street to thereby form a modified layer inside the wafer and a dividing step of applying an external force to the wafer to thereby divide the wafer into the individual chips along each street with the modified layer functioning as a division start point. In the modified layer forming step, the modified layer is formed at each intersection of the crossing streets at a height where cracking can be avoided on the corner edges of each chip obtained by dividing the wafer.

In a semiconductor wafer with a supporting tape attached to the back side of the wafer, a coating member having a refractive index close to that of the supporting tape is formed on a pear-skin surface of the supporting tape to thereby planarize the pear-skin surface. Thereafter, a pulsed laser beam is applied from the upper side of the coating member to the semiconductor wafer in the condition where the focal point of the pulsed laser beam is set at a predetermined depth in the semiconductor wafer. Accordingly, the pulsed laser beam can be sufficiently focused inside the semiconductor wafer to thereby well form a modified layer inside the semiconductor wafer.

Workpiece dividing method

A workpiece dividing method for dividing a workpiece having an uneven incident surface upon which a pulsed laser beam falls. The workpiece dividing method includes a coating step of applying a coating member to the incident surface of the workpiece, thereby planarizing the incident surface of the workpiece, the coating member transmitting the pulsed laser beam and having a refractive index close to that of the workpiece for the pulsed laser beam, a modified layer forming step of applying the pulsed laser beam to the workpiece from the side of the incident surface in the condition where a focal point of the pulsed laser beam is set inside the workpiece after performing the coating step, thereby forming a modified layer inside the workpiece, and a dividing step of applying an external force to the workpiece after performing the modified layer forming step, thereby dividing the workpiece as starting from the modified layer formed inside said workpiece as a break start point.

Method of dividing a workpiece having an uneven surface

A laser processing apparatus including a holding unit for holding a workpiece, a processing unit for applying a laser beam to the workpiece held by the holding unit, a surface displacement detecting unit for detecting a surface displacement of the workpiece, and a focal position adjusting unit for adjusting the position of a focusing lens provided in the processing unit according to the surface displacement detected. The surface displacement detecting unit includes a detecting light source capable of oscillating light having a plurality of wavelengths different from the wavelength of the laser beam and a wavelength selecting section configured to select one of the plurality of wavelengths as the wavelength of detecting light. The detecting light having the selected wavelength is focused by the focusing lens and applied to the workpiece.

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Tokyo, Japan

Kenji Furuta