CN2638084Y - Simplified fly eye type light beam homogenizer - Google Patents

Abstract

A simplified fly's eye type beam homogenizer for excimer laser is composed of two groups of quartz cylindrical mirrors with mutually perpendicular busbars, which are superimposed and combined to form a 3*3 fly's eye lens array. The central part is a square or rectangular hollow, and the light receiving width of the cylindrical mirror and the width of the central hollow are divided into three equal parts. When the excimer laser with a rectangular (or shaped into a square) spot irradiates the homogenizer, the central hollow part directly passes the light, while the light beams of the edge part are converged by the cylindrical mirror and overlapped at a certain designed position thereafter, that is, the laser beam is divided into nine parts and then superimposed to achieve the effect of averaging the light intensity. Compared with the prior art, the simplified fly's eye type excimer laser beam homogenizer of the utility model has a simple structure, achieves the effect of a 3*3 fly's eye homogenizer, overcomes the difficulties in processing, and is flexible and maneuverable.

Description

Simplified fly-eye beam homogenizer

Technical field:

The utility model relates to a simplified fly-eye lens array light beam homogenizer applied to excimer lasers.

Background technique:

The principle of the excimer laser beam homogenizer is to divide the laser beam into multiple sub-beams, and then re-superimpose, so that the laser light intensity can be averaged on the superimposed surface, so as to improve the uniformity of the beam cross-sectional light intensity distribution. In prior art, commonly used have two kinds. One is a waveguide homogenizer (published in "China Laser" 1995 VolA22, No. 12 894-896), although its production is relatively simple, but the loss of light energy is relatively large. The other is the fly-eye beam homogenizer (published in "China Laser" 1999 Vol A26, No.6 560-564), which can achieve very good results and is currently the most commonly used beam homogenizer in laser lithography and microfabrication. , the disadvantage is that the processing is relatively difficult.

Invention content:

The purpose of the utility model is to improve the beam quality of an excimer laser, simplify the processing difficulty of a beam homogenizer, and provide a simplified fly-eye beam homogenizer.

The purpose of this utility model is achieved through the following measures:

A simplified fly-eye beam homogenizer, which is characterized by superposition and combination of two sets of quartz cylindrical mirrors whose busbars are perpendicular to each other to form a 3*3 fly-eye lens array. The central part is a square or rectangular hollow, and the light-receiving width of the cylindrical mirror and the width of the central hollow form three equal parts. When the excimer laser with a rectangular (or shaped into a square) spot irradiates the homogenizer, the central hollow part passes through the light directly, while the beams at the edge part are converged by the cylindrical mirror and overlap at a certain design position thereafter, that is, The laser beam is divided into nine parts and then superimposed to achieve the effect of light intensity average.

Compared with the prior art, the simplified fly-eye excimer laser beam homogenizer of the utility model has a simple structure, achieves the effect of a 3*3 fly-eye homogenizer, overcomes difficulties in processing, and is flexible and maneuverable.

Description of drawings:

Fig. 1 is the schematic structural diagram of the simplified fly-eye beam homogenizer of the present utility model,

Fig. 2 is the optical path schematic diagram of the utility model using state

Detailed ways

Please refer to Fig. 1 and Fig. 2, Fig. 1 is a schematic diagram of the structure of the simplified fly-eye beam homogenizer of the present invention, and Fig. 2 is a schematic diagram of the light path of the utility model in use. It can be seen from the figure that the simplified fly-eye beam homogenizer of the present invention is composed of two sets of quartz cylindrical mirrors 3, 4, 5, and 6 whose busbars are perpendicular to each other to form a 3*3 fly-eye lens array. The central part 9 is a square or rectangular hollow, and the light-receiving width of the cylindrical mirror and the width of the central hollow form three equal parts in the horizontal and vertical directions respectively.

The optical path of the utility model in use state is as shown in Figure 2. The output laser light from the laser 1 is attenuated by the attenuator 2 and then enters the homogenizer 8 composed of four cylindrical mirrors 3, 4, 5, 6, and a uniform light spot is obtained on the receiving screen 7. Taking the laser spot size of 30mm in the horizontal direction and 20mm in the vertical direction as an example, the vertical hollow formed by the cylindrical mirrors 3 and 4 is 6.7mm, and the optical axis is 0.9° to the laser direction; while the horizontal direction formed by the cylindrical mirrors 5 and 6 The hollow out is 10mm, the focal length is 200mm, and the optical axis is 1.4° from the laser direction. The material of the cylindrical mirror is JGS1. The receiving screen 7 is located at a distance of 8400mm from the homogenizer. The trapezoidal prism homogenizer of this embodiment is applied to a 308nm XeCl excimer laser, and has good beam uniformity.

Claims (2)

1. A simplified fly-eye beam homogenizer, which is characterized in that a 3*3 fly-eye lens array is formed by stacking two sets of quartz cylindrical mirrors whose busbars are perpendicular to each other. 2. The simplified fly-eye beam homogenizer according to claim 1, characterized in that the central part of the 3*3 fly-eye lens array is hollowed out in a square or rectangle, and the light-receiving width of the cylindrical mirror is the same as that of the hollowed out center. The width is divided into thirds.

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