US-12619167-B2 - Optical inspection device for surface of reticle pod and optical inspection method for surface of reticle pod

US12619167B2US 12619167 B2US12619167 B2US 12619167B2US-12619167-B2

Abstract

An optical inspection device for a surface of a reticle pod includes a carrier platform having a carrier surface, a light source module, a photographic module, and a control module. The light source module includes first and second light sources for irradiating the carrier surface in first and second directions, respectively. An angle of an included angle between the first direction and the carrier surface is greater than an angle of an included angle between the second direction and the carrier surface. The control module is signally connected to the camera module, first light source, and second light source. The control module controls one of the first light source and second light source to turn on and the other one to turn off. An optical inspection method for a surface of a reticle pod is further provided to operate to inspect a reticle pod efficiently and precisely.

Inventors

YIN-FENG CHAN
Lin-Hsin Tu
Ming-Mo Lo

Assignees

GUDENG EQUIPMENT CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20230518
Priority Date: 20230303

Claims (4)

1 . An optical inspection device for a surface of a reticle pod, comprising: a carrier platform having a carrier surface; a light source module including a first light source and a second light source, wherein the first light source irradiates the carrier surface in a first direction, the second light source irradiates the carrier surface in a second direction, an angle of an included angle between the first direction and the carrier surface is greater than an angle of an included angle between the second direction and the carrier surface; a camera module, wherein a lens of the camera module faces the carrier surface; a power module signally connected to the control module; a control module signally connected to the camera module, the first light source, and the second light source; and a switch including a first relay and a second relay, wherein the first relay is disposed on a signal path between the control module and the first light source, and the second relay is disposed on a signal path between the control module and the second light source, wherein the control module switches the first light source and the second light source on and off in turn through the first relay and the second relay, and wherein the control module controls the camera module to capture a first image and a second image individually through switching the first relay and the second relay when the camera module resides at the same position, and then the control module controls the power module to move the camera module relative to the carrier platform to a next position and controls the camera module to capture images individually at the next position through switching the first relay and the second relay.
2 . The optical inspection device for a surface of a reticle pod according to claim 1 , wherein the power module is power connected to the carrier platform, and the control module controls the carrier platform to move relative to the camera module.
3 . The optical inspection device for a surface of a reticle pod according to claim 1 , wherein the power module is power connected to the camera module, and the control module controls the camera module to move relative to the carrier platform.
4 . An optical inspection method for a surface of a reticle pod, comprising the steps of: switching a first relay to cause a first light source to irradiate a component of a reticle pod in a first direction and turning off a second light source; capturing a partial surface of the component of the reticle pod by a camera module to obtain a first image; switching a second relay to cause the second light source to irradiate the component of the reticle pod in a second direction and turning off the first light source, wherein an angle of an included angle between the first direction and a carrier surface is greater than an angle of an included angle between the second direction and the carrier surface; capturing the partial surface of the component of the reticle pod to obtain a second image; determining whether a defect exists according to the first image and the second image; moving the camera module relative to the component of the reticle pod to a next position; and switching the first relay and the second relay in turn at the next position to obtain images of another partial surface different from the partial surface.

Description

CROSS-REFERENCE TO RELATED APPLICATION This non-provisional application claims priority under 35 U.S.C. § 119 (a) on Patent Application No(s). 112107864 filed in Taiwan, R.O.C. on Mar. 3, 2023, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present application relates to inspection devices and inspection methods, and in particular to an optical inspection device for a surface of a reticle pod and an optical inspection method for a surface of a reticle pod. 2. Description of the Related Art In advanced lithography processes in the field of semiconductors, and more particularly for the extreme ultraviolet light (EUV) lithography process, an extremely high level of cleanliness of the process environment is required. In case of contamination of a reticle by particles, defects in the lithography process can result. To meet requirements of cleanliness and reticle protection, a reticle pod is generally used to block external particles. Thus, the cleanliness and lack of existence of defects (such as scratches) of a reticle pod are critical. However, the industry yet lacks an inspection apparatus capable of efficiently and accurately inspecting a reticle pod. In addition, unlike wafer or reticles having only one single plane to be inspected, a reticle pod has multiple high and low planes as well as respective obverse and reverse sides of upper and lower covers that need to be inspected. Therefore, how to inspect surface of the reticle pod quickly and accurately is an important issue. BRIEF SUMMARY OF THE INVENTION To overcome various issues of surface inspection for a reticle pod of the prior art, the present application provides an optical inspection device for a surface of a reticle pod and an optical inspection method for a surface of a reticle pod. To achieve the above and other objectives, an optical inspection device for a surface of a reticle pod provided in the application comprises: a carrier platform having a carrier surface; a light source module including a first light source and a second light source, wherein the first light source irradiates the carrier surface in a first direction, the second light source irradiates the carrier surface in a second direction, an angle of an included angle between the first direction and the carrier surface is greater than an angle of an included angle between the second direction and the carrier surface; a camera module, wherein a lens of the camera module faces the carrier surface; and a control module signally connected to the camera module, the first light source, and the second light source, the control module controls one of the first light source and the second light source to be turned on and the other to be turned off. In an embodiment of the application, the optical inspection device for a surface of a reticle pod further comprises a power module signally connected to the control module. In an embodiment of the application, the power module is power connected to the carrier platform, and the control module controls the carrier platform to move relative to the camera module. In an embodiment of the application, the power module is power connected to the camera module, and the control module controls the camera module to move relative to the carrier platform. In an embodiment of the application, the first light source is an external coaxial light source, and the second light source is a side light source. In an embodiment of the application, the first light source is an internal coaxial light source, and the second light source is a side light source. In an embodiment of the application, the optical inspection device for a surface of a reticle pod further comprises a switch, being signally connected to the control module, the first light source, and the second light source. The application further provides an optical inspection method for a surface of a reticle pod, comprising the steps of: irradiating a component of a reticle pod by a first light source in a first direction; capturing a partial surface of the component of the reticle pod to obtain a first image; irradiating the component of the reticle pod by a second light source in a second direction, wherein an angle of an included angle between the first direction and a carrier surface is greater than an angle of an included angle between the second direction and the carrier surface; capturing the partial surface of the component of the reticle pod to obtain a second image; and determining whether a defect exists according to the first image and the second image. In an embodiment of the application, the optical inspection method for a surface of a reticle pod further comprises the step: switching between the first light source and the second light source with a switch. In an embodiment of the application, the optical inspection method for a surface of a reticle pod further comprises the step: moving the component of the reticle po