US-12628607-B2 - Optical heating device with angled light holding substrate and method of heating treatment thereof

US12628607B2US 12628607 B2US12628607 B2US 12628607B2US-12628607-B2

Abstract

The invention provides an optical heating device and method of heating treatment capable of adjusting the illuminance distribution on the main surface of a substrate to be treated more precisely. An optical heating device that heats a substrate to be treated by irradiating light, the optical heating device includes; a support member supporting the substrate to be treated; and a light source unit including a plurality of LED substrates each having a first main surface on which a plurality of LED elements are mounted; in which at least one of the plurality of LED substrates is arranged such that the first main surface is inclined to the second main surface of the substrate to be treated when the substrate to be treated is supported by the support member.

Inventors

Tomonori Yoshida
Takahiro Inoue

Assignees

USHIO DENKI KABUSHIKI KAISHA

Dates

Publication Date: 20260512
Application Date: 20230125
Priority Date: 20220126

Claims (9)

1 . An optical heating device that heats a substrate to be treated by irradiating light, the optical heating device comprising: a support member supporting the substrate to be treated; and a light source unit including a plurality of LED substrates each having a first main surface on which a plurality of LED elements are mounted, wherein at least one of the plurality of LED substrates is arranged such that the first main surface is inclined to a second main surface of the substrate to be treated when the substrate to be treated is supported by the support member, each of the plurality of LED substrates are arranged so that an angle between the first main surface and the second main surface of the substrate to be treated is between 20° and 60° when the substrate to be treated is supported by the support member, and each of the plurality of LED substrates are arranged to satisfy formulae (1) to (3) below, wherein a distance between a center of the LED substrate at the first main surface and the substrate to be treated at the first main surface when the substrate to be treated is supported by the support member is Wd; a distance from a center of the substrate to be treated to the center of the LED substrate at the first main surface when viewed from a direction orthogonal to the second main surface of the substrate to be treated is Rd; an angle between the first main surface of the LED substrate and the second main surface of the substrate to be treated is θ, 60 mm≤ Wd ≤200 mm (1) 0.75 ≤Rd/Wd≤ 2.5 (2) arctan( Rd /(2 ·Wd ))≤0≤arctan( Rd/Wd ) (3).
2 . An optical heating device that heats a substrate to be treated by irradiating light, the optical heating device comprising: a support member supporting the substrate to be treated; and a light source unit including a plurality of LED substrates each having a first main surface on which a plurality of LED elements are mounted, wherein at least one of the plurality of LED substrates is arranged such that the first main surface is inclined to a second main surface of the substrate to be treated when the substrate to be treated is supported by the support member, and at least of the plurality of LED substrates is arranged to satisfy formula (4) below, wherein an angle between the first main surface and the second main surface of the substrate to be treated under a condition that the substrate to be treated is supported by the support member is θ, a separation distance between a first LED element located closest from the second main surface to a normal direction of the second main surface and the substrate is D 1 , a separation distance between a second LED element mounted on the LED substrate and the first LED element located farthest from the second main surface to the normal direction is D 2 , 2 tan 2θ/cos θ≥ D 2 /D 1 (4).
3 . The optical heating device according to claim 2 , wherein the light source unit includes a first LED substrate that is inclined such that a normal line of the first main surface from the light source unit toward the substrate to be treated is directed toward a center portion of the substrate to be treated under the condition that the substrate to be treated is supported by the support member, and a second LED substrate that is inclined to cause the normal line of the first main surface from the light source unit toward the substrate to be treated to be directed toward a peripheral edge of the substrate to be treated.
4 . The optical heating device according to claim 2 , further comprising an angle adjusting mechanism configured to adjust the angle θ by changing position of the LED substrate.
5 . The optical heating device according to claim 4 , further comprising a controller configured to determine a value of the angle θ based on the separation distance D 1 and the separation distance D 2 , and drive the angle adjusting mechanism based on the determined the angle θ.
6 . The optical heating device according to claim 2 , further comprising an angle sensor configured to measure the angle θ between the first main surface and the second main surface.
7 . The optical heating device according to claim 2 , wherein the support member includes a rotation mechanism that rotates the substrate to be treated around an axis that is orthogonal to the second main surface and passes through a center of the second main surface.
8 . A method of heating treatment is a heating treatment method in which a substrate to be treated supported by a support member is heated by irradiating light emitted from a light source unit including a plurality of LED substrates on which a group of LED elements are mounted on a first main surface of the substrate to be treated, the method comprising: irradiating the substrate to be treated with heating light containing light emitted from the light source unit configured to satisfy formula (4) in a state where the substrate to be treated is supported by the support member, wherein θ is an angle between the first main surface and a second main surface of the substrate to be treated under a condition that the substrate to be treated is supported by the support member, D 1 is a separation distance between a first LED element located closest from the second main surface to a normal direction of the second main surface and the substrate, D 2 is a separation distance between a second LED element mounted on the LED substrate and the first LED element located farthest from the second main surface to the normal direction, 2 tan 2θ/cos θ≥ D 2 /D 1 (4).
9 . The method of heating treatment according to claim 8 , further comprising determining the angle θ based on the separation distance D 1 and the separation distance D 2 , and changing position of the LED substrate based on the determined the angle θ.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present invention claims the benefit of priority to Japanese Patent Application No. 2022-010007 filed on Jan. 26, 2022, and No. 2022-051454 filed on Mar. 28, 2022 with the Japanese Patent Office, the entire contents of which are incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an optical heating device and a method of heating treatment. Description of the Related Art A semiconductor production process includes various heat treatments applied to a substrate to be treated such as a semiconductor wafer, including depositing, oxidizing and diffusing, reforming, or annealing. These treatments are often performed by a method of heating treatment through light irradiation, which allows for contactless treatment. As a device for heating a substrate to be treated, there has been known a device provided with a lamp such as a halogen lamp or a solid light source such as an LED and configured to irradiate the substrate to be treated with light for heating (hereinafter, occasionally called “heating light”). For example, Patent Document 1 describes a heating apparatus equipped with a plurality of LEDs. PRIOR ART DOCUMENT Patent Document Patent Document 1: JP-A-2020-009927 SUMMARY OF THE INVENTION In recent years, technological developments such as the miniaturization of semiconductor manufacturing processes have led to a demand for heating equipment capable of more uniform heat treatment. Therefore, the inventor has been diligently studying a heating device that can heat treat substrates to be treated with a more uniform temperature distribution and has found that the following issues exist. As in the heating device described in Patent Document 1 above, a heating device in which a plurality of solid-state light sources such as LEDs are mounted as light sources emitting light for heating, the plurality of solid-state light sources are arranged on a plane parallel to the main surface of the substrate to be treated placed on a support member. The reasons why such a configuration is generally adopted include the fact that it is easier to predict and examine the illuminance distribution on the main surface of the substrate to be treated by aligning the separation distance between the main surface of the substrate and each solid-state light source, and it is also easier to control the illuminance distribution on the main surface of the substrate to be treated. However, when a plurality of solid-state light sources are soldered or otherwise fixed to the main surface of the substrate on which the solid-state light sources are mounted, it is difficult to change the position of each solid-state light source later. Therefore, in a heating device based on mounting a plurality of solid light sources on a plane parallel to the main surface of a substrate placed on a support member, the only way to fine-tune the illuminance distribution on the main surface of the substrate to be treated was to move to parallel the substrate on which the solid light sources were fixed. However, the arrangement of the plurality of solid light sources does not change when the solid light sources are moved in parallel with the substrate to which they are fixed. Therefore, depending on the position where the substrate is moved, the configuration of the solid-state light source arrangement may be inappropriate. If the solid-state light source is moved parallel to the substrate in a direction perpendicular to the substrate's main surface, the light emitted from the solid light source is irradiated onto the substrate before it spreads sufficiently, resulting in uneven irradiation. If the solid-state light source is too far away from the substrate to be treated, the light cannot provide sufficient illumination due to insufficient illumination. In other words, it was difficult for conventional heating devices to finely adjust the illuminance distribution of light irradiated to each substrate to be treated. In view of the above problem, it is an object of the present invention to provide an optical heating device and method of heating treatment capable of adjusting the illuminance distribution on the main surface of a substrate to be treated more precisely. An optical heating device according to the present invention is an optical heating device that heats a substrate to be treated by irradiating light, the optical heating device includes: a support member supporting the substrate to be treated; anda light source unit including a plurality of LED substrates each having a first main surface on which a plurality of LED elements are mounted; whereinat least one of the plurality of LED substrates is arranged such that the first main surface is inclined to a second main surface of the substrate to be treated when the substrate to be treated is supported by the support member. In the present specification, “inclination” means a state in which