Exposure system

Abstract

The utility model provides an exposure system, which comprises an exposure light source arranged above an exposure plane, and an optical axis of the exposure light source is arranged along a first direction; the backlight source is arranged below the exposure plane, and the optical axis of the backlight source is coaxial with the exposure optical axis; the dichroic mirror is arranged along an angular bisector of an acute angle or a right angle formed between the first direction and the second direction when viewed in the third direction; the exposure light path can completely transmit the dichroic mirror, and the backlight light path propagates along a first direction and can be reflected by the dichroic mirror to propagate along a second direction; the first direction and the second direction intersect, and the first direction and the second direction are both perpendicular to the third direction. According to the exposure system provided by the invention, the exposure operation can be carried out without transferring after deviation correction of the exposure position of the silicon wafer is completed, so that the situation that position deviation still occurs after deviation correction and before exposure can be avoided, and the use of a high-precision transfer device can also be avoided, so that the equipment cost is saved while high-precision exposure is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of semiconductor manufacturing equipment, and more specifically, to an exposure system. Background Art

[0002] The photolithography process of silicon wafers includes at least positioning and exposure steps. Generally speaking, in the related technology, the work station for positioning and pre-exposure correction of silicon wafers is set at a different position from the exposure station. As a result, in the process of moving from the positioning station to the exposure station after visual positioning and position correction, the silicon wafer is very likely to be more or less displaced, thereby affecting the exposure accuracy; and if the displacement after positioning and correction is to be completely avoided, the accuracy requirements for the silicon wafer transfer mechanism are extremely high, resulting in huge equipment costs. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide an exposure system to solve the technical problem in the prior art that the silicon wafer needs to be transported during the exposure process after deflection correction, which affects the exposure accuracy of the silicon wafer.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted in the embodiment of the present application is to provide an exposure system, which includes:

[0005] An exposure light source is arranged above the exposure plane and its optical axis is arranged along a first direction;

[0006] A backlight source is arranged below the exposure plane and its optical axis is coaxial with the exposure optical axis;

[0007] A dichroic mirror, wherein the dichroic mirror is arranged along the bisector of the acute angle or right angle formed between the first direction and the second direction when viewed from the third direction; the exposure light path can completely pass through the dichroic mirror, and the backlight light path propagates along the first direction and can be reflected by the dichroic mirror to propagate along the second direction;

[0008] The first direction and the second direction intersect each other, and both the first direction and the second direction are perpendicular to the third direction.

[0009] Optionally, the first direction is perpendicular to the second direction.

[0010] Optionally, the dichroic mirror is in any one of a rectangular, polygonal or circular shape.

[0011] Optionally, the dichroic mirror can transmit ultraviolet light and violet light with a wavelength of 280nm to 455nm, and the dichroic mirror can reflect yellow light and red light with a wavelength of 577nm to 770nm.

[0012] Optionally, the area of ​​the dichroic mirror is 1.2 to 2 times the exposure area of ​​the exposure light source.

[0013] Optionally, the exposure light source includes a light-emitting chip, a light guide rod and a lens group, the light guide rod is arranged between the light-emitting chip and the lens group; the side length of the light outlet on the light guide rod is greater than the side length of the light entrance; the light guide rod is used to form a rectangular light spot.

[0014] Optionally, the light guide rod is conical, the area of ​​the light entrance is larger than the light emitting area of ​​the light emitting chip; the ratio of the side lengths of the light exit and the light entrance is less than 8:1; the length of the light guide rod is 1 to 5 times the maximum side length of its light exit.

[0015] Optionally, the lens group includes a first lens group and a second lens group, both of which have positive focal lengths, and the focal length of the first lens group is smaller than that of the second lens group; the first lens group includes two plano-convex lenses and a biconvex lens arranged between the two plano-convex lenses, and the convex surfaces of the two plano-convex lenses are both facing the biconvex lenses; the second lens group includes two plano-convex lenses, and the convex surface of each plano-convex lens faces the light direction.

[0016] Optionally, a visual device is further included, wherein the imaging optical axis of the visual device is arranged along the second direction so as to be able to obtain the backlight reflected by the dichroic mirror.

[0017] The exposure system provided in the embodiment of the present application has at least the following beneficial effects:

[0018] A dichroic mirror is arranged above the exposure plane, and at the same time, a backlight source is arranged below the exposure plane, so that the exposure light path and the backlight light path can be propagated coaxially between the exposure plane and the dichroic mirror, and the dichroic mirror can completely transmit the exposure light path and completely reflect the backlight light path. In this way, the positioning and deviation correction of the silicon wafer position on the exposure plane can be achieved by arranging a visual device in the second direction, and then the exposure operation can be carried out without transferring the silicon wafer after the exposure position correction is completed, thereby avoiding the situation where position deviation occurs after correction and before exposure, and also avoiding the use of practical high-precision transfer devices, so as to save equipment costs while achieving high-precision exposure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 Schematic diagram of an exposure system in some embodiments of the present application;

[0021] Figure 2Schematic diagram of lens groups in some embodiments of the present application. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0023] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it may be directly on the other element or indirectly on the other element.

[0025] When an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0026] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0028] In the description of the present application, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0029] Please also read Figure 1 to Figure 2 , the exposure system provided in the embodiment of the present application is now described.

[0030] It can be understood that, in the exposure machine, a silicon wafer position correction device can be provided on the exposure plane A, and a mask plate position correction device can also be provided at the installation position of the mask plate 500 directly above the exposure plane A, so as to complete the position positioning and correction of the silicon wafer 400 before exposure by adjusting the relative position between the silicon wafer 400 and the mask plate 500.

[0031] It should be noted that, in the description of the following embodiments, the first direction and the third direction are perpendicular to each other, and the second direction and the third direction are also perpendicular to each other.

[0032] refer to Figure 1 and Figure 2 The exposure system described in the present application includes an exposure light source 100, a backlight light source 200 and a dichroic mirror 300. The exposure light source 100 and the dichroic mirror 300 are both arranged above the exposure plane A, and the backlight light source 200 is arranged below the exposure plane A and its light can penetrate through the exposure plane A.

[0033] The optical axis of the exposure light source 100 is arranged along the first direction, that is, the exposure light path a propagates along the first direction.

[0034] The dichroic mirror 300 is disposed on the exposure light path a and is located directly above the exposure plane A. Furthermore, viewed along the third direction, the dichroic mirror 300 is disposed along the angle bisector of the acute angle or right angle formed between the first direction and the second direction.

[0035] The backlight light source 200 is arranged directly above the exposure plane A and the backlight light path b is coaxially arranged with the exposure light path a. In addition, the dichroic mirror 300 is arranged so that the light wavelength of the exposure light source 100 can completely pass through the dichroic mirror 300, and at the same time, the light wavelength of the backlight light source 200 can be completely reflected by the dichroic mirror 300 to continue to propagate along the second direction.

[0036] In this way, the exposure contour area of ​​the exposure light source 100 on the exposure plane A can overlap with the backlight contour area of ​​the backlight light source 200 on the exposure plane A. Specifically, within the distance interval between the exposure plane A and the dichroic mirror 300, the backlight light path b and the exposure light path a can achieve coaxial propagation, for example, the exposure light path a propagates along a first direction, and the backlight light path b propagates in a direction opposite to the first direction; and at the dichroic mirror 300, the backlight light path b is completely reflected so that the propagation direction changes from the direction opposite to the first direction to the second direction, and the exposure light path a completely penetrates the dichroic mirror 300 and continues to propagate along the first direction to irradiate the exposure plane A.

[0037] In practical applications, a visual device 600 may be provided in the second direction and on the propagation path of the backlight path b. The visual device 600 may be a CCD camera to image the backlight reflected by the dichroic mirror 300, thereby obtaining the position data of the silicon wafer 400 on the exposure plane A.

[0038] By setting up the exposure system in this way, combined with setting a silicon wafer position correction device on the exposure plane A or setting a mask plate position correction device at the mask plate position above the exposure plane A, the silicon wafer 400 can be positioned and position-corrected on the exposure plane A before exposure, and there is no need to transfer the silicon wafer 400 after positioning and position correction, that is, after positioning and position correction, it can directly enter the exposure process, thereby avoiding the problem of position error accumulation and error increase caused by multiple transfers of the silicon wafer 400 in the traditional solution; at the same time, it can also avoid the need to use high-precision moving equipment required in the traditional solution to transfer the silicon wafer to the exposure position after position correction, thereby reducing equipment costs; in addition, it can also avoid possible damage caused by frequent movement of the silicon wafer 400, thereby improving the process yield.

[0039] In some embodiments, the first direction and the second direction are perpendicular to each other, that is, the angle between the dichroic mirror 300 and the exposure plane A is 45°.

[0040] In some embodiments, the shape of the dichroic mirror 300 is any one of a rectangular shape, a polygonal shape or a circular shape, which can be selected according to the type of light spot required on the exposure plane A, but is not limited thereto.

[0041] In some embodiments, the dichroic mirror 300 can transmit ultraviolet and violet light with a wavelength of 280nm to 455nm, that is, the exposure light source 100 can select ultraviolet and violet light within the wavelength range of 280nm to 455nm. Generally, the transmittance of the dichroic mirror 300 to ultraviolet and violet light is above 85%.

[0042] Meanwhile, the dichroic mirror 300 can reflect yellow light and red light with wavelengths of 577nm to 770nm, that is, the backlight source 200 can select yellow light and red light within the wavelength range of 577nm to 770nm. Generally, the transmittance of the dichroic mirror 300 to yellow light and red light is above 80%.

[0043] In a further embodiment, the area of ​​the dichroic mirror 300 is 1.2 to 2 times the exposure area of ​​the exposure light source 100. In this way, the exposure energy of the exposure light source 100 on the exposure plane A can be effectively guaranteed.

[0044] Based on any of the above embodiments, the exposure light source 100 includes a light-emitting chip 110, a light guide rod 120 and a lens group 130, the light guide rod 120 is arranged between the light-emitting chip 110 and the lens group 130; the side length of the light outlet on the light guide rod 120 is greater than the side length of the light entrance; the light guide rod 120 is used to form a rectangular light spot.

[0045] Furthermore, the light guide rod 120 is tapered, and the area of ​​the light inlet is larger than the light emitting area of ​​the light emitting chip 110, so that the exposure light can be prevented from being completely refracted into the light guide rod 120, so as to improve the effective utilization rate of the exposure light; in addition, the light inlet and light outlet of the light guide rod 120 are both rectangular, so that the light spot emitted by the exposure light source 100 changes to a rectangular shape to match the shape of the silicon wafer. At the same time, the ratio of the side lengths of the light outlet and the light inlet on the light guide rod 120 is less than 8:1; the length of the light guide rod 120 is 1 to 5 times the maximum side length of its light outlet, which is determined specifically according to the ratio between the area of ​​the light emitting chip 110 and the area of ​​the exposure light spot to be formed.

[0046] Further, the lens group 130 includes a first lens group 131 and a second lens group 132, both of which have positive focal lengths, and the focal length of the first lens group 131 is smaller than the focal length of the second lens group 132. Specifically, the first lens group 131 includes two plano-convex lenses 1311 and a biconvex lens 1312 disposed between the two plano-convex lenses 1311, and the convex surfaces of the two plano-convex lenses 1311 are both oriented toward the biconvex lens 1312, and the first lens group 131 is used to amplify the incident exposure light spot; the second lens group 132 includes two plano-convex lenses 1321, and the convex surface of each plano-convex lens 1321 is oriented toward the light direction, and the second lens group 132 is used to collimate and optimize the exposure light spot amplified by the first lens group 131.

[0047] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An exposure system, characterized in that: include: An exposure light source is arranged above the exposure plane and its optical axis is arranged along a first direction; A backlight source is arranged below the exposure plane and its optical axis is coaxial with the exposure optical axis; A dichroic mirror, viewed along a third direction, the dichroic mirror being arranged along an angle bisector of an acute angle or a right angle formed between the first direction and the second direction; The exposure light path can completely transmit the dichroic mirror, and the backlight light path propagates along the first direction and can be reflected by the dichroic mirror to propagate along the second direction; The first direction and the second direction intersect each other, and both the first direction and the second direction are perpendicular to the third direction.

2. The exposure system according to claim 1, characterized in that: The first direction is perpendicular to the second direction.

3. The exposure system according to claim 1, wherein: The dichroic mirror is in a rectangular or circular shape.

4. The exposure system according to claim 1, wherein: The dichroic mirror can transmit ultraviolet light and violet light with a wavelength of 280nm to 455nm, and the dichroic mirror can reflect yellow light and red light with a wavelength of 577nm to 770nm.

5. The exposure system according to claim 4, characterized in that: The area of ​​the dichroic mirror is 1.2 to 2 times the exposure area of ​​the exposure light source.

6. The exposure system according to any one of claims 1 to 5, characterized in that: The exposure light source includes a light emitting chip, a light guide rod and a lens group, wherein the light guide rod is arranged between the light emitting chip and the lens group; the side length of the light outlet on the light guide rod is greater than the side length of the light entrance; the light guide rod is used to form a rectangular light spot.

7. The exposure system according to claim 6, characterized in that: The light guide rod is conical, and the area of ​​the light entrance is larger than the light emitting area of ​​the light emitting chip; the ratio of the side lengths of the light exit and the light entrance is less than 8:1; the length of the light guide rod is 1 to 5 times the maximum side length of the light exit.

8. The exposure system according to claim 6, characterized in that: The lens group includes a first lens group and a second lens group, both of which have positive focal lengths, and the focal length of the first lens group is smaller than that of the second lens group; the first lens group includes two plano-convex lenses and a biconvex lens arranged between the two plano-convex lenses, and the convex surfaces of the two plano-convex lenses are both facing the biconvex lens; the second lens group includes two plano-convex lenses, and the convex surface of each plano-convex lens faces the light direction.

9. The exposure system according to any one of claims 1 to 5, characterized in that: A visual device is also included, wherein the imaging optical axis of the visual device is arranged along the second direction so as to be able to obtain the backlight reflected by the dichroic mirror.

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