TWI674475B - Dust detection mechanism - Google Patents

Abstract

The invention relates to a micro-dust detection mechanism, in particular to a micro-dust detection mechanism for detecting the surface of a light-transmitting member such as a photomask. The body is provided with an optical image module on a body, and the body is provided with a body for inspection. A stage module of a photomask, which is located below the optical image module and can be relatively linearly displaced. The invention is characterized in that the body is provided with at least two relatively equidistant and equiangular angles on the periphery of the optical image module. Light source module, the light source structures have a laser light emitting element capable of adjusting the light emitting angle, so that the light source emitted by these laser light emitting elements can be focused within the detection range of the optical image module, and the laser light The light source of the light source group is close to or equal to the surface of the photomask to be inspected, thereby providing an effective light source to avoid image interference caused by the light source penetrating through the light-transmitting member, and can effectively handle the size of the dust and improve its detection. Efficiency and accuracy, reduce unnecessary misjudgment, and further improve the yield of subsequent wafer processing.

Description

Dust detection mechanism

The invention belongs to the technical field of detecting the surface of a light-transmitting member, and more particularly, it is a dust detection mechanism that can reduce the mutual interference of the images on the surfaces of both sides of the light-transmitting member, so that the size of the dust can be quickly and accurately determined.

According to the current semiconductor manufacturing process, the photolithography and etching process are used to complete the wafer surface pattern production. The mask used for the lithography process has an indispensable feature. Key position. The photomask is a light-transmitting glass sheet with a specific pattern painted, which includes a patterned pattern area for transferring a pattern on the patterned area to a photoresist on a wafer using a light source, and then subjected to an etching process. Complete the pattern on the wafer surface. In order to protect the graphics on the pattern area, a mask film (Pellicle) is usually arranged above the pattern area to prevent the graphics on the pattern area from being scratched, polluted or damaged.

However, mask contamination has always been a problem. In a photolithography process with an operating wavelength equal to or less than 248 nanometers, high-resolution photomasks are particularly vulnerable to contamination. These pollutions include particles, crystals, or fogging that are attached to the surface of the photomask. The use of such contaminated photomasks in the yellow light lithography process will directly affect the graphics on the photomask and further cause wafers. The yield of manufacturing integrated circuits is reduced. Although cleaning the surface of the photomask can solve the aforementioned problem of dust pollution, A large number of cleanings will not only reduce the service life of the photomask, but also increase its cleaning cost. More importantly, it will lengthen the waiting time of the operation, and require more accurate photomasks, or affect the output of the wafer.

Therefore, pollution tolerance standards are generally set for different photomasks and tested when the photomask enters the process or storage. If the pollution does not exceed the allowable standard, it will not be cleaned, otherwise it will be cleaned. The traditional detection method is mainly manual visual inspection, but due to time consuming, and easily due to the subjective judgment of inspectors, long-term work, or eye fatigue, and other factors, misjudgment. At present, the industry has also developed different photomask detection equipment for automatic detection of pollution.

Existing photomask detection equipment uses an optical module [image sensor, CCD element, or CMOS element] to scan the entire photomask surface to detect contamination or sediment on the photomask. The light source comes from above or below the reticle, plus the reticle is made of a transparent glass sheet. This will cause graphic interference on the lower surface and cannot effectively detect fine dust on the upper surface. Therefore, the principle of the current optical module is based on the use of Optical scanning technology in the form of a small spot of a light beam (such as a laser beam or an electron beam). However, the cost of the existing optical scanning system is quite expensive, and the photomask is usually composed of a very flat transparent quartz plate or a transparent glass plate, which makes it difficult to focus during optical scanning and misjudgment due to ghosting. Due to the size of the dust particles, its detection and scanning speed is very slow, and at the same time it is affected by the aforementioned misjudgement. The size of the detected dust particles can only reach 50um * 50um, which limits the detection capacity of smaller dust particles. It gradually fails to meet the requirements for the detection of dust particles with smaller and smaller wire diameters of existing integrated circuits.

Furthermore, because it is based on beam scanning, it is not only slow to scan, but also difficult to form a complete photomask surface. The position of the dust cannot be provided for the operator to perform the positioning directly after the detection to move the optical module directly above the dust for manual interpretation, nor can it be used as a basis for determining the cause of subsequent production abnormalities.

In other words, with the existing inspection methods or equipment, it is not only easy to misjudge the size of the dust, and the detection speed is slow. At the same time, the detection capacity is limited. How to solve the aforementioned problems is an important issue for the industry.

In view of this, the present inventor has made in-depth discussions on the problems faced by the aforementioned existing light-transmitting reticle during dust inspection, and actively seeks a solution through the inventor's years of experience in related development, with continuous efforts Research and development have finally succeeded in creating a dust detection mechanism to overcome the difficulties and inconveniences caused by the difficulty of rapid detection of size and location by existing people.

Therefore, the main object of the present invention is to provide a dust detection mechanism that can effectively detect the size and position of dust, thereby reducing misjudgments and providing subsequent interpretation processing, thereby improving the efficiency and yield of subsequent wafer processing.

In addition, a second main object of the present invention is to provide a dust detection mechanism capable of improving the detection capability, which can effectively detect smaller dust particles to meet the requirements of finer semiconductor manufacturing processes.

Furthermore, another main object of the present invention is to provide a dust detection mechanism capable of rapid scanning, which can complete and quickly inspect the surface of the photomask, thereby improving the efficiency and frequency of photomask inspection.

To this end, the present invention mainly implements the above-mentioned objects and effects through the following technical means, including at least: A machine body having a moving axis; a stage module slidingly arranged on the movement axis of the machine body; the stage module is capable of carrying the linear displacement of the light-transmitting member to be measured along the movement axis of the machine body; an optical image The module is arranged on the body for linear displacement with respect to the stage module, and the optical image module is composed of at least one image sensing element with a linear scanning function. The linear scanning extension axis and the movement axis of the stage module are vertically staggered; and at least two light source modules are separately arranged on at least one of two sides of the movement axis of the body, and the light source modules each have a laser Light emitting parts, and the light emitting points of the laser light emitting parts of these fine-tuning modules are equidistant and equal in height to the staggered points of the moving axis of the light transmitting part to be measured and the detection extension axis of the optical image module. The included angle between the light emitting point of the laser light emitting element and the detection surface of the light transmitting element to be measured is 0 to 6 degrees.

Therefore, through the specific implementation of the aforementioned technical means, the dust detection mechanism of the present invention can use an optical image processing module composed of a linear image photosensitive element to quickly scan the surface of the photomask and pass through the light guide plate of the oblique light guide unit. The function of the light source can make the light from the light source obliquely be scanned at the scanning position of the optical image processing module, thereby improving its focusing effect, thereby improving the recognition rate of pollutants, so it can effectively improve its inspection efficiency and accuracy, reduce unnecessary manpower and misjudgment. The condition can further improve the yield of subsequent wafer processing, and improve its work efficiency, increase its added value, and improve its economic benefits.

In order to make your reviewers better understand the composition, features, and other objectives of the present invention, the following are examples of the preferred embodiments of the present invention, and are described in detail with the drawings, so that those who are familiar with the technical field can implement it. .

(10) ‧‧‧Body

(15) ‧‧‧Linear slide

(20) ‧‧‧Carrier Module

(21) ‧‧‧Lifting mechanism

(22) ‧‧‧Substrate

(23) ‧‧‧Body

(230) ‧‧‧Oblique Guide

(24) ‧‧‧Guide

(25) ‧‧‧Body

(250) ‧‧‧Slope Guide

(26) ‧‧‧Guide

(27) ‧‧‧Stand

(28) ‧‧‧Guide

(29) ‧‧‧Driver

(30) ‧‧‧Positioning agency

(31) ‧‧‧Floor

(32) ‧‧‧Fixed parts

(320) ‧‧‧Support block

(33) ‧‧‧Adjustment

(34) ‧‧‧Platform

(35) ‧‧‧Pushing piece

(36) ‧‧‧Pneumatic Stretching Cylinder

(37) ‧‧‧Bar seat

(38) ‧‧‧arrive

(39) ‧‧‧height detection element

(40) ‧‧‧Optical Image Module

(41) ‧‧‧Image sensor

(50) ‧‧‧Light source module

(51) ‧‧‧Laser Light

(55) ‧‧‧Fine-tuning module

(80) ‧‧‧Transmitting piece to be tested

(X) ‧‧‧Move axis

(Y) ‧‧‧Detect extension axis

(P) ‧‧‧ stagger

The first figure is a schematic plan view of a device to which the dust detection mechanism of the present invention is applied.

Second figure: A schematic plan view of the dust detection mechanism of the present invention, for illustrating the relative relationship of each component in a top view.

Third figure: A schematic side plan view of the dust detection mechanism of the present invention for explaining the relative relationship of each component on the side.

FIG. 4 is a schematic diagram of the appearance of a stage module in the dust detection mechanism of the present invention.

Fifth figure: The exploded schematic diagram of the lifting mechanism of the stage module in the dust detection mechanism of the present invention, for explaining its configuration.

FIG. 6 is a schematic diagram of an external appearance of a positioning mechanism of a stage module in the dust detection mechanism of the present invention, for explaining its configuration.

The present invention is a dust detection mechanism. The accompanying drawings illustrate specific embodiments of the present invention and its components. All references to front and back, left and right, top and bottom, upper and lower, and horizontal and vertical are used only. For convenience of description, the present invention is not limited, and its components are not limited to any position or spatial direction. The dimensions specified in the drawings and the description can be changed according to the design and requirements of the specific embodiments of the present invention without departing from the scope of the patent application of the present invention.

The present invention is a micro-dust detection mechanism for detecting the surface of a light-transmitting member such as a semiconductor photomask, as shown in the first, second and third figures, and is provided on a body (10) for carrying a to-be-tested The stage module (20) of the light piece (80), and the body (10) is provided above the stage module (20) with a light transmitting piece (80) for testing Optical image module (40), the optical image module (40) and the stage module (20) can be relatively linearly displaced, and the body (10) is provided with at least two peripheral edges corresponding to the light-transmitting member (80) to be measured The light source group can be focused on the light source module (50) of the optical image module (40), and the body (10) is composed of a series of metal bones and plates for other modules of the present invention. For example, the stage module (20), optical image module (40) and related electrical control, air pressure and other parts are assembled, and the body (10) is provided with a stage module (20) for the optical image module ( 40) The linear slide rail (15) with relative linear displacement below, the moving axis of the linear slide rail (15) is defined as the X axis; the stage module (20) is also shown in the fourth figure, It has a lifting mechanism (21) that can move the light-transmitting member (80) up and down, and the stage module (20) also has a light-transmitting member (80) that can be quickly positioned at the detection position. Positioning mechanism (30). The positioning mechanism (30) can be set on the top surface of the lifting mechanism (21). As shown in the fifth figure, the lifting mechanism (21) has a linear sliding mechanism that can be slidably disposed on the body (10). The base plate (22) of the rail (15) for the benefit A servo motor and a lead screw are used to linearly move relative to the optical image module (40), and a base body (23) with an inclined guide surface (230) is slid on the base plate (22). The base body (23) and the base plate (23) 22) A guide member (24) including a guide rail and a guide seat is provided between the opposite surfaces, so that the seat body (23) can be linearly displaced relative to the base plate (22), and the inclined guide surface (230) of the seat body (23) slides up A bearing body (25) with a relatively inclined guide surface (250) is provided, and a guide including a guide rail and a guide seat is provided between the seat (23) and the opposite inclined guide surfaces (230, 250) of the bearing body (25). The lead piece (26), and the base plate (22) is fixed on the end of the support body (25) different from the base body (23) with a vertical plate (27). A vertical plate (27) is provided between the end plate and the end surface of the support body (25). A vertical guide (28) including a guide rail and a guide seat, so that the support body (25) can only move up and down Displacement, and the base plate (22) is provided at one end of the base body (23) different from the base body (25) with a driving member (29) including a servo motor and a lead screw for actuating the base body (23) relative to the base body (25) ) Forward and backward displacement, and the supporting body (25) can use the inclined guide surface (230, 250) to generate a lifting effect along the guide plate (27) of the vertical plate (27); and the positioning mechanism of the carrier module (20) (30) There is a bottom plate (31) for locking on the top surface of the lifting mechanism (21), as shown in the sixth figure, and the bottom plate (31) is provided with a fixing at the corner corresponding to the light-transmitting member (80) to be tested Piece (32), and each fixing piece (32) is provided with a supporting block (320) for supporting the corners of the light-transmitting member (80) to be tested, the supporting block (320) can be selected from polyetheretherketone [ PEEK] material, so that the light-transmitting member (80) to be tested can be horizontally placed on the positioning mechanism (30), and a height-adjusting group (an adjustable group can be further provided between the supporting block (320) and the fixing member (32) ( 33) for selectively adjusting the height of the corresponding corner of the light-transmitting member (80) to be measured to ensure the level of the surface of the light-transmitting member (80) to be measured, and positioning the top surface of the bottom plate (31) of the mechanism (30) on A platform (34) is provided in the space surrounded by the fixing member (32), and the platform (34) corresponds to the test Each edge of the light piece (80) is provided with a pressing piece (35) for selectively abutting against the edge of the light-transmitting piece (80) to be tested. The pressing pieces (35) are provided with a pressure on the platform (34). An extension cylinder (36), and a rod seat (37) is arranged on the extension rod of the pneumatic extension cylinder (36), and at least two abutment columns (38) on the same axis are provided on the rod seat (37) for receiving air pressure The extension cylinder (36) functions to selectively abut against the light-transmitting member (80) to be tested. When all the pressing members (35) are retracted synchronously, the pressing columns (38) of each of the pressing members (35) can be used. ) Simultaneously push the light-transmitting member (80) to be tested, so that different light-transmitting members (80) can be positioned at the same detection position to improve the detection accuracy, and the positioning mechanism (30) is provided with at least A height detecting element (39) capable of detecting the thickness of the light-transmitting member (80) to be measured, and the height detecting element (39) is coupled with the driving mechanism of the aforementioned lifting mechanism (21). The moving part (29) forms an electrical connection for matching the height of the carrier (25) of the lifting mechanism (21) with the thickness adjustment of the transparent member (80) to be measured; further, as shown in the second and third figures, the optical The image module (40) has an automatic photographing function, and the optical image module (40) can be composed of at least one image sensing element (41) that is linearly scanned [which can be selected from a CCD element or a CMOS element] And the linear scanning extension axis of the image sensing elements (41) is defined as the Y axis, and the linear scanning extension axis (Y) and the movement axis (X) of the stage module (20) are vertically staggered, It is defined as the interlaced point (P). The present invention uses two side-by-side image sensing elements (41) as the main embodiment for one-time detection of the width, Or parallel surfaces on both sides [such as the two surfaces of the protective film of the photomask], so that the light-transmitting member (80) to be measured needs to be displaced uniaxially relative to the optical image module (40) in the horizontal plane to improve the detection speed and accuracy And the focal height (H1) of the image sensing element (41) of the optical image module (40) and the detection surface of the light-transmitting member (80) to be tested is 280mm ~ 320mm, As an example, the light mask of the body has an optimal focal length (H1) of 293 mm to 305 mm; as for the light source modules (50), each of the light source modules (50) has a laser light emitting element (51), and the laser light emitting element (51) ) Can be selected from a laser diode with a wavelength of 600nm ~ 700nm, such as a red laser diode, the laser light emitting part (51) is correspondingly arranged on the body (10) through a trimming module (55) Both sides of the moving axis (X) of the light-transmitting member (80) to be measured can be adjusted by the fine-tuning module (55), and the fine-tuning module (55) can adjust the X-axis, Y-axis, Z-axis, and the rotation angle of each axis. The staggered point of the light emitting point of the laser light emitting part (51) of the module (55) and the moving axis (X) of the light transmitting member (80) to be measured and the detection extension axis (Y) of the optical image module (40) (P) It is arranged in an equidistant and equal height manner. The present invention uses a detection mask as an example. It uses four groups of light. The source module (50) is the main embodiment, and the X-axis distance (L2) between the light source emission point and the staggered point (P) of the laser light emitting parts (51) of the light source modules (50) is 300 mm to 320 mm And the Y-axis distance (L1) between the light emitting point and the staggered point (P) of the laser light emitting part (51) of these light source modules (50) is 120mm ~ 130mm, and the relative angle between the two is about [20 Degrees to 25 degrees], and the light emitting point (51) of the light emitting module (50) of the light source module (50) and the height (H2) of the testing surface of the light transmitting member (80) are 3 mm to 33 mm [both Relative angle included angle is about 0.5 degrees to 6 degrees], the preferred embodiment of the present invention is the X-axis of the light source emission point and the staggered point (P) of the laser light emitting parts (51) of the light source modules (50) The distance (L2) is 307mm ~ 311mm, and the Y-axis distance (L1) between the light source emission point and the staggered point (P) of the laser light emitting part (51) of these light source modules (50) is 123mm ~ 127mm, And the height (H2) between the light emitting point of the laser light emitting part (51) of the light source module (50) and the detection surface of the light transmitting part (80) to be measured is a distance of 3mm ~ 13mm [the relative angle between the two About 0.5 degrees to 3 degrees]; through this, through the light source in different directions, so that (80) The dust on the surface can be effectively developed, and the misjudgment caused by the surrounding shadows can be reduced, so that the optical image module (40) can accurately detect the size and position of the dust, and further can make smaller dust, according to The actual measurement can detect 10um * 10um dust, which greatly enhances its detection ability, and then forms a dust detection mechanism that can detect quickly and accurately.

When the present invention performs the actual operation of the testing of the light-transmitting member (80), as shown in the first, second and third figures, taking the semiconductor photomask as an example, it makes the light-transmitting member (80) to be tested The photomask is placed on the supporting mechanism (30) of the positioning mechanism (30) of the stage module (20) [as shown in the fourth and sixth figures], and the gas of the pressing member (35) is used The extension cylinder (36) retracts the abutment post (38), so that the light-transmitting member (80) to be tested can be positioned in the same position on the stage module (20) in a horizontal position, and the positioning mechanism (30) The height detection element (39) can simultaneously detect the thickness of the light-transmitting member (80) to be measured, and lift the light-transmitting member (80) to the corresponding detection through the driving member (29) of the lifting mechanism (21). Height [as shown in the fourth and fifth figures], and simultaneously turn on each of the laser light emitting element (51) of the image sensing element (41) of the optical image module (40) and the light source module (50); The stage module (20) carries a linear array sensing line of the light-transmitting member (80) to be measured along the movement axis (X) of the body (10) and passes through the image sensing element (41) of the optical image module (40) Since the laser light emitting elements (51) of the surrounding light source modules (50) project the light sources in an equidistant and equiangular manner, the dust on the surface of the light transmitting member (80) to be measured can be developed by the surrounding light sources. In addition, the light source from the surroundings can be used to reduce the misjudgment of the size of the dust caused by the shadow caused by the light source, so that the image sensing element (41) of the optical image module (40) can accurately detect the size and position of each dust. And one Make less dust, dust can be detected based on the measured 10um * 10um, significantly increasing its detection capability.

Through the above description, the present invention utilizes a series of equidistant and equiangular at least two light source modules (50), so that the dust on the surface of the light-transmitting member (80) to be measured can be effectively lighted and transmitted through the optical image module The image sensing element (41) of the linear scanning function of (40) can quickly and effectively detect the size and position of dust, thereby reducing misjudgments, and for subsequent interpretation processing, and can effectively detect smaller dust particles. In order to meet the requirements of the finer semiconductor manufacturing process, a complete photomask surface can be formed to allow the detection equipment to remember the size and position of the dust, so that the operator can locate the dust after inspection, and cooperate with the optical imaging module (40 ) Available functions Automatic photo archiving, compared with before and after cleaning, in order to judge the cleaning effect, and can be convenient for manual inspection, interpretation and recording later, and can be used as the basis for determining the cause of subsequent production abnormalities, greatly improving its practicality.

In summary, it can be understood that the present invention is a very creative invention. In addition to effectively solving the problems faced by practitioners, it greatly enhances the efficacy, and has not seen the same or similar product creation or product creation in the same technical field. It is used publicly and has the enhancement of efficacy. Therefore, the present invention has met the requirements of "novelty" and "progressiveness" of the invention patent, and is an application for an invention patent in accordance with the law.

Claims (8)

A dust detection mechanism for detecting the surface of a light-transmitting member includes at least: a body having a moving shaft; and a stage module, which is slidably disposed on the movement shaft of the body, and the stage module is capable of carrying The light-transmitting member to be measured is linearly displaced along the movement axis of the body; an optical image module is provided on the body for relative displacement between the optical image module and the stage module, and the optical image module is It is composed of at least one image sensing element that is linearly scanned, and the linear scanning extension axis of the image sensing elements is vertically staggered with the movement axis of the stage module; and at least two light source modules are arranged on the body At least one of the two sides of the moving axis, the light source modules each have a laser light emitting element, and the light emitting point of the laser light emitting elements of the light source modules and the moving axis and optical of the light transmitting element to be measured The staggered points of the detection extension axis of the image module are equidistant and equiangular, and the included angle between the light emitting point of the laser light emitting part and the detection surface of the light transmitting part to be measured is 0.5 to 6 degrees. According to the dust detection mechanism described in item 1 of the patent application scope, the laser light emitting components of the light source modules may be selected from red laser diodes with a wavelength of 600 nm to 700 nm. For example, the dust detection mechanism described in item 1 of the patent application scope, wherein the focal height of the image sensing elements from the detection surface of the transparent member to be measured is 280mm ~ 320mm, and the light source of the laser light emitting module of the light source module The X-axis distance between the emission point and the interlaced point of the linear scanning extension axis of the image sensing elements and the moving axis of the stage module is 300mm ~ 320mm, and the light source emission point of the laser light emitting components of these light source modules is The Y-axis distance of the staggered points is 120 mm to 130. The dust detection mechanism according to item 1 of the patent application scope, wherein when the dust detection mechanism is used to detect a semiconductor mask, the focal height of the image sensing elements from the detection surface of the light-transmitting member to be measured is 293 mm to 305 mm, and The X-axis distance between the light emitting point of the laser light emitting parts of the light source modules and the intersection point of the linear scanning extension axis of the image sensing element and the moving axis of the stage module is 307mm ~ 311mm, and the light sources The Y-axis distance between the light emitting point of the laser light emitting part of the module and the aforementioned staggered point is 123mm ~ 127mm, and the angle between the light emitting point of the laser light emitting part of these light source modules and the detection surface of the light transmitting part to be measured The angle is 0.5 to 3 degrees. The dust detection mechanism according to item 1 of the scope of patent application, wherein the laser light-emitting component is provided on the body through a trimming mold component, and the trimming module may have an adjustable X-axis, Y-axis, and Z-axis Adjust the rotation angle of each axis or its combination. According to the dust detection mechanism described in item 1 of the scope of patent application, the stage module has a positioning mechanism for quickly positioning the light-transmitting member to be detected at the detection position, the positioning mechanism has a bottom plate, and the bottom plate is Each corner of the light-transmitting member is provided with a fixing member, and each fixing member is provided with a support block for supporting each corner of the light-transmitting member to be measured, and a height-adjusting group is further provided between the support block and the fixing member. In addition, the top surface of the bottom plate of the positioning mechanism is provided with a pressing member for selectively abutting the edge of the transparent member to be tested at each edge corresponding to the transparent member to be measured, and at least two synchronizable members are provided on the pressing members. The abutment posts which are selectively attached to the edges of the light-transmitting members to be tested enable different light-transmitting members to be positioned at the same detection position. The dust detection mechanism according to item 6 of the scope of patent application, wherein the stage module has a lifting mechanism capable of driving the up and down displacement of the light-transmitting member to be measured, and the lifting The mechanism has a base plate, and a base body with a slanted guide surface is slid on the base plate, and a support body with a slanted guide surface is slid on the slanted guide surface of the base body, and the base plate is fixed on the base body at a different end from the base body. A vertical plate is provided for the support body to be displaced along the vertical plate, and the base plate is provided with a driving member for selectively actuating the base body at the end of the base body different from the support body, so that the support body can use the inclined guide surface, And the lifting effect is generated along the vertical plate. For example, the dust detection mechanism described in item 7 of the scope of the patent application, wherein the positioning mechanism of the stage module may be provided on the top surface of the lifting mechanism, and furthermore, the positioning mechanism is provided with at least one light-transmitting member that can be detected. The height detection element of the thickness, which is electrically connected with the driving member of the lifting mechanism for adjusting the height of the carrier top of the lifting mechanism in accordance with the thickness of the transparent member to be measured.