KR-20260067332-A - METHOD FOR PRODUCING SYNTHETIC QUARTZ GLASS SUBSTRATE

Abstract

The present invention provides a method for manufacturing a synthetic quartz glass substrate, characterized by comprising an evaluation process for evaluating the depth of a processed altered layer on a cut surface of a synthetic quartz glass substrate, and a removal process for removing the processed altered layer based on the evaluation result of the depth of the processed altered layer. By removing the altered processing layer based on an evaluation of the depth of the altered processing layer on the machined surface, it is possible to remove the altered processing layer reliably and efficiently, thereby increasing the productivity of the synthetic quartz glass substrate.

Inventors

• 안도, 마사오

Assignees

• 신에쓰 가가꾸 고교 가부시끼가이샤

Dates

Publication Date

20260512

Application Date

20251031

Priority Date

20241105

Claims (7)

1. A method for manufacturing a synthetic quartz glass substrate, characterized by including an evaluation process for evaluating the depth of a processed altered layer on a cutting surface of a synthetic quartz glass substrate, and a removal process for removing the processed altered layer based on the evaluation result of the depth of the processed altered layer.
2. A method for manufacturing a synthetic quartz glass substrate according to claim 1, wherein the evaluation process evaluates whether the arithmetic mean height (Sa), skewness (Ssk), and kurtosis (Sku) on the cutting surface of the synthetic quartz glass substrate are predetermined values, and performs the removal process according to the evaluation result.
3. A method for manufacturing a synthetic quartz glass substrate according to paragraph 2, wherein, in the evaluation process, a synthetic quartz glass substrate satisfying the predetermined value is selected, and for the synthetic quartz glass substrate satisfying the predetermined value, the removal process is performed according to predetermined conditions.
4. A method for manufacturing a synthetic quartz glass substrate according to claim 2 or 3, wherein the predetermined values are an arithmetic mean height (Sa) of 2.0 μm or less, an absolute value of skewness (Ssk) of 0.8 or less, and a kurtosis (Sku) of 5.0 or less.
5. A method for manufacturing a synthetic quartz glass substrate according to claim 4, wherein the removal process is performed with a removal depth of 30 μm on a synthetic quartz glass substrate satisfying the above predetermined value.
6. A method for manufacturing a synthetic quartz glass substrate according to claim 1, wherein the removal process includes mirror polishing or wet etching.
7. A method for manufacturing a synthetic quartz glass substrate according to claim 1, wherein the depth of the processed altered layer is 30 μm or less.

Description

Method for producing synthetic quartz glass substrate The present invention relates to a method for manufacturing a synthetic quartz glass substrate. Synthetic quartz glass substrates used in semiconductor substrates, optical components, microfluidics, microlens arrays, etc., are provided for practical use by forming through- or non-through holes, grooves, steps, etc., through cutting processes. When performing such cutting processes, it is common to use tools such as grinding wheels or drills. At this time, a processing altered layer is formed on the cutting surface, but in order to remove this processing altered layer, it is necessary to set a large amount of grinding or polishing in subsequent grinding or polishing processes, and this becomes one of the factors that lower productivity. Furthermore, fixed-grain tools typically used in such cutting processes are dressed before or during the process to adjust the protrusion amount of the abrasive grains or to create cutting edges. Since the condition of the tool after dressing is not always constant, there is a risk that an unusually deep altered layer may develop or that significant fluctuations in the depth of the altered layer may occur due to the lifespan of the fixed-grain tool. Regarding this problem, for example, Japanese Patent Publication No. 2012-035330 (Patent Document 1) discloses a method for suppressing the occurrence of a deep processing altered layer on the cutting surface by making the width of the particle size distribution of abrasive particles contained in a grinding stone less than a predetermined value in the manufacture of a glass substrate for a magnetic recording medium. In addition, Japanese Patent Publication No. 2012-027976 (Patent Document 2) describes a method for suppressing the formation of a deep processing altered layer on the cutting surface by specifying the surface roughness of the cutting surface of a fixed abrasive tool in the manufacture of a glass substrate for a magnetic recording medium. The present invention will be described in more detail below. The method for manufacturing a synthetic quartz glass substrate according to the present invention comprises, as described above, an evaluation process for evaluating the depth of a processed altered layer on a cutting surface of a synthetic quartz glass substrate, and a removal process for removing the processed altered layer based on the evaluation result of the depth of the processed altered layer. In the present invention, the synthetic quartz glass substrate provided in the evaluation and removal processes may be one obtained by conventional methods. For example, a synthetic quartz glass ingot prepared by reacting a silica raw material compound, such as a silane compound or a siloxane compound, with an oxyhydrogen flame can be formed into a desired shape, annealed to a desired thickness, sliced, lapped, and, if necessary, polished to obtain a raw material substrate, which can then be manufactured by rough polishing and fine polishing. The shape of the synthetic quartz glass substrate can be any shape, such as a square or a circle, and there are no particular restrictions on the shape or size. For example, for a square glass substrate, a size of 10 mm × 10 mm to 300 mm × 300 mm is suitably used. For a circular glass substrate, a substrate with a diameter of 10 to 300 mm is suitably used. The thickness of the synthetic quartz glass substrate is also not particularly limited, but is preferably 0.01 mm or more, particularly 0.05 mm or more, particularly 0.1 mm or more, and preferably 300 mm or less, particularly 100 mm or less, particularly 30 mm or less. The present invention evaluates and removes the depth of the processed altered layer that occurs during cutting, but as the substrate to be applied, a synthetic quartz glass substrate as described above can be used, which has undergone cutting to impart a shape suitable for various applications. In that case, although not specifically limited, it is preferable that the depth of the processed altered layer on the machined surface be 30 μm or less. If the depth of the processed altered layer exceeds 30 μm, it becomes disadvantageous in terms of productivity because the amount removed increases during the process of removing the processed altered layer. If the depth of the processed altered layer is 30 μm or less, as described in detail below, the removal of the processed altered layer can be performed uniformly under conditions where at least 30 μm can be removed, and there is no need to measure the depth of the processed altered layer each time, so quality and productivity can be achieved simultaneously. Cutting of a synthetic quartz glass substrate can be performed using a device such as a numerically controlled machine tool, such as a machining center. Specifically, the cutting process can be performed using a grinding wheel tool, which has diamond abrasive grains, cubic boron nitride abrasive grains, etc. fixed by el