WAFER MANUFACTURING METHODS AND COMPONENT CHIP MANUFACTURING METHODS

Abstract

A wafer manufacturing method for manufacturing a wafer (1) from an ingot (7, 11), the wafer manufacturing method comprising: a cutting step comprising manufacturing a plurality of wafers (1) by cutting the ingot (7, 11); a grinding step comprising grinding the wafer (1) produced during the cutting step to a predetermined thickness; a polishing step comprising polishing an upper surface (1a) and / or a lower surface (1b) of the wafer (1) that was ground during the grinding step; a resistance measuring step comprising measuring the resistance of the wafer (1); after the resistance measuring step, an information printing step comprising forming a letter, a number, or a mark (3) representing information regarding the resistance on the upper surface (1a), the lower surface (1b), and / or inside the wafer;anddetermining irradiation conditions of a laser beam to be applied to the wafer based on the information regarding the resistance;

Claims

[1] A wafer manufacturing method for producing a wafer (1) from an ingot (7, 11), the wafer manufacturing method comprising: a cutting step comprising producing a plurality of wafers (1) by cutting the ingot (7, 11); a grinding step comprising grinding the wafer (1) produced during the cutting step to a predetermined thickness; a polishing step comprising polishing an upper surface (1a) and / or a lower surface (1b) of the wafer (1) ground in the grinding step; a resistance measuring step with a resistance measurement of the wafer (1); after the resistance measuring step, an information printing step comprising forming a letter, a number or a mark (3) representing information relating to the resistance on the upper surface (1a), the lower surface (1b) and / or inside the wafer; and Determining irradiation conditions of a laser beam to be applied to the wafer based on the resistance information. [2] A wafer manufacturing method for producing a wafer (1) from an ingot (7, 11), the wafer manufacturing method comprising: a planarization step comprising planarizing an end surface (11a, 11b) of the ingot (7, 11); a resistance measuring step comprising measuring a resistance of the ingot (7, 11) at a planarized end face (11a, 11b); a peel layer forming step comprising forming a peel layer (23) inside the ingot (7, 11) by positioning a focal point (44b) of a first laser beam (44a) having a wavelength transmissible through the ingot (7, 11) at a depth from the end surface (11a) corresponding to a thickness of the wafer (1) to be produced, and irradiating the ingot (7, 11) with the first laser beam (44a); an information printing step comprising forming a letter, a number, or a mark (3) containing information relating to the resistance measured during the resistance measuring step on the planarized end surface (11a) and / or inside the ingot (7, 11) by positioning a focal point of a second laser beam (44c) in a region in which no components (31) are to be formed in the wafer (1) to be produced, and irradiating the ingot (7, 11) with the second laser beam (44c); and a wafer manufacturing step comprising manufacturing the wafer (1) by dividing the ingot (7, 11) with the stripping layer (23) as a starting point and stripping the manufactured wafer (1). [3] A wafer manufacturing method according to claim 2, wherein the ingot (7, 11) is a SiC single-crystal ingot having the end face (11a), an opposite end face (11b) on a side opposite the end face (11a), a c-axis extending from the end face (11a) to the opposite end face (11b), and a c-plane perpendicular to the c-axis, the c-axis is inclined with respect to a perpendicular to the end surface (11a), the c-plane is inclined with respect to the end surface (11a) at a deviation angle (α), and in the peeling layer forming step, the peeling layer (23) having a modified layer (25) is formed by repeating a processing feed step of forming the modified layer (25) in a linear shape by moving the ingot (7, 11) and the focal point (44b) of the first laser beam (44a) relative to each other in a first direction perpendicular to a direction in which the deviation angle (α) is formed and parallel to the end face (11a) and an adjusting step of moving the ingot (7, 11) and the focal point (44b) relative to each other in a second direction parallel to the direction in which the deviation angle (α) is formed and the end face (11a). [4] A wafer manufacturing method according to any one of claims 1 to 3, wherein during the information printing step, the number representing the resistance is formed as the information regarding the resistance. [5] A component chip manufacturing method for manufacturing a plurality of component chips by dividing a wafer (1) by laser processing, wherein a plurality of planned dividing lines (29) crossing each other are arranged on an upper surface (1a) of the wafer (1), a component (31) is formed in each of regions defined by the planned dividing lines (29) on the upper surface (1a), the component chip manufacturing method comprising: a loading step comprising loading the wafer (1) into a laser processing device (46); a laser processing step comprising forming modified layers (25) in the wafer (1) along the planned separation lines (29) by positioning a focal point (44b) of a laser beam (44a) with a wavelength that passes through the wafer (1) inside the wafer (1) and applying the laser beam (44a) to the focal point (44b) while moving the focal point (44b) and the wafer (1) relative to each other in a direction parallel to the upper surface (1a); and a separation step comprising producing a plurality of component chips by dividing the wafer (1) with the modified layers (25) as a starting point, wherein a letter, a number or a mark (3) representing the information relating to the resistance of the wafer (1) is formed in or on the wafer (1), and in the laser processing step, the wafer (1) is irradiated with the laser beam (44a) under an irradiation condition determined on the basis of the resistance of the wafer (1), wherein the resistance can be obtained from the letter, number or mark (39) representing the information regarding the resistance of the wafer (1).

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