Disco Corporation

Kunimitsu Takahashi

Kazuya Hirata

Yoko Nishino

Naoki Murazawa

Nobuyasu Kitahara

Yoshiaki Yodo

Joel Koerwer

Junichi Kuki

Hiroto Yoshida

Yujiro Sudo

Asahi Nomoto

Chikara Aikawa

Seiji Fujiwara

Kuo Wei Wu

An ingot is processed by applying exciting light, and detecting fluorescence occurring from an upper surface of the ingot. A distribution of the number of photons of the fluorescence on the upper surface of the ingot is stored as two-dimensional data in association with XY coordinate positions, and a Z-coordinate position at which the two-dimensional data is obtained is also stored. A laser beam forms a peeling layer by irradiating the ingot while positioning the condensing point of the laser beam at a depth corresponding to the thickness of a wafer from the upper surface of the ingot. A wafer is separated from the ingot with the peeling layer as a starting point, and three-dimensional data is generated representing the distribution of the number of photons of the fluorescence in the whole of the ingot on the basis of two-dimensional data at each Z-coordinate position of the ingot.

Processing method and processing apparatus for ingot

Apparatus for inspecting the tension of a tape adhered to an annular frame having, in the center thereof, an opening for accommodating a wafer includes: a frame support section that supports the annular frame, a light source that applies light toward the tape, an imaging camera that captures, through the tape, the light applied from the light source, a first polarizing plate disposed between the tape and the light source, and a second polarizing plate disposed between the tape and the imaging camera and positioned so as to shield the light of linearly polarized light transmitted through the first polarizing plate. If distortion is generated in a polarization plane of the light due to application, onto the tape, of the light of the linearly polarized light transmitted through the first polarizing plate, the light is transmitted through the second polarizing plate, and the imaging camera images the transmitted light.

Inspection apparatus

A protective film thickness measuring method includes a step of applying light to a top surface of a wafer in a state in which no protective film is formed and measuring a first reflection intensity of the light reflected from the top surface, a step of forming the protective film including a light absorbing material, a step of irradiating the protective film with exciting light of a wavelength at which the light absorbing material fluoresces and measuring a second reflection intensity including fluorescence of the protective film and the light reflected from the top surface, and a step of excluding reflection intensity of patterns formed on the top surface, by subtracting the measured first reflection intensity from the measured second reflection intensity, and calculating fluorescence intensity of the protective film.

Protective film thickness measuring method

A facet region detecting method for detecting a facet region of an SiC single crystal ingot includes: an irradiation step of irradiating a first surface of the SiC single crystal ingot with light; a fluorescence intensity detection step of detecting the intensity of fluorescence generated from the first surface of the SiC single crystal ingot by the light; and a determination step of determining a region of the first surface where the fluorescence intensity is comparatively low as a facet region and determining a region where the fluorescence intensity is comparatively high as a non-facet region.

Facet region detecting method and detecting apparatus

A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. A wafer producing method includes a separation start point forming step of applying a laser beam to the ingot to form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer, thus forming a separation start point. The focal point of the laser beam is relatively moved in a first direction perpendicular to a second direction where a c-axis in the ingot is inclined by an off angle with respect to a normal to the upper surface. The off angle is formed between the upper surface and a c-plane perpendicular to the c-axis, thereby linearly forming the modified layer extending in the first direction. The laser beam is applied to the ingot with the direction of the polarization plane of the laser beam set to the first direction.

Wafer producing method

A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. The wafer producing method includes a separation start point forming step of setting the focal point of a laser beam having a transmission wavelength to the ingot inside the ingot at a predetermined depth from the upper surface of the ingot. The separation start point forming step includes a first step of forming the separation start point with a first power and a second step of setting the focal point at the modified layer previously formed in the first step and then applying the laser beam to the ingot with a second power higher than the first power at an increased repetition frequency in the condition where the energy per pulse of the laser beam is the same as that in the first step, thereby separating the cracks from the modified layer.

A crystal wafer is produced from a hexagonal crystal ingot. A separation start point is formed by setting the focal point of a laser beam inside the ingot at a predetermined depth, which depth corresponds to the thickness of the wafer to be produced. The laser beam is applied to the upper surface of the ingot while relatively moving the focal point and the ingot to form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer along a c-plane in the ingot, thus forming the separation start point. First the laser beam is scanned from a scanning start point to a scanning end point on the ingot. Then the laser beam is scanned from the scanning end point to the scanning start point. The first and second steps are alternately repeated to separate the cracks from the modified layer.

A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. A separation start point is formed by setting a focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to a thickness of the wafer to be produced. The laser beam is applied to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and form cracks extending from the modified layer along a c-plane, thus forming a separation start point. The wafer is separated by immersing the ingot in water and then applying ultrasonic vibration to the ingot, thereby separating a plate-shaped member having a thickness corresponding to the thickness of the wafer from the ingot.

A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. The wafer producing method includes a separation start point forming step of setting the focal point of a laser beam to the inside of the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer, thus forming a separation start point. A plate-shaped member having a thickness corresponding to the thickness of the wafer is separated from the ingot at the separation start point after performing the separation start point forming step, thus producing the wafer from the ingot.

A wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot includes a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer, thus forming a separation start point. In the separation start point forming step, the laser beam is applied to the ingot plural times with the focal point of the laser beam set at the modified layer previously formed, thereby separating the cracks from the modified layer.

A wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot is disclosed. The wafer producing method includes a separation start point forming step of forming a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer to thereby form a separation start point in the ingot. The separation start point forming step includes a first separation start point forming step of setting the focal point of a laser beam at a first depth which is N times (N is an integer not less than 2) the depth corresponding to the thickness of the wafer from the upper surface of the ingot and next applying the laser beam to the ingot to thereby form a first separation start point composed of a first modified layer and first cracks extending therefrom.

A wafer producing method produces a hexagonal single crystal wafer from a hexagonal single crystal ingot. The method includes a separation start point forming step of setting the focal point of a laser beam to the inside of the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer, thus forming a separation start point. The separation start point forming step includes an indexing step of relatively moving the focal point in a direction of formation of an off angle to thereby index the focal point by a predetermined index amount.

A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. A separation start point is formed by setting a focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and form cracks extending from the modified layer along a c-plane, thus forming a separation start point. The focal point is indexed by relatively moving the focal point in the direction where an off angle is formed and the c-plane is inclined downward.

A method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot includes a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface and cracks extending from the modified layer along a c-plane in the ingot, thus forming a separation start point. The ingot is immersed in water after forming the separation start point in the ingot, and ultrasonic vibration is applied to the ingot to thereby separate a plate-shaped member corresponding to the wafer from the ingot.

A wafer processing method divides a wafer into a plurality of individual devices along a plurality of crossing division lines formed on the front side of the wafer. The method includes a functional layer removing step of applying a COlaser beam to the wafer along each division line with the spot of the COlaser beam, having a width corresponding to the width of each division line set on the upper surface of each division line, thereby removing a functional layer along each division line to form a groove along each division line where the functional layer has been removed, and a groove shaping and debris removing step of applying a laser beam having a wavelength in the ultraviolet region to the wafer along each groove, thereby removing debris sticking to the bottom surface of each groove and also shaping the side walls of each groove.

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Tokyo, Japan

Kunimitsu Takahashi