CN211628003U - A phase plate that produces a special focused spot - Google Patents

Abstract

The utility model discloses a phase plate for generating special focusing light spots. The phase plate is circular, and the incident light is phase-modulated through the structure of its surface to generate a special focused spot. It is characterized in that the phase plate has a circular phase distribution, which can make the transmitted parallel light beams produce special focusing spots on the focusing plane, and at the same time, changing the wavelength of the incident light can also obtain focusing spots of different sizes. It has broad application prospects in the field of lithography, especially in the field of maskless lithography.

Description

A phase plate that produces a special focused spot

technical field

The utility model relates to the field of phase control, in particular to a phase plate for generating special focusing light spots.

Background technique

In the integrated circuit, the circuit pattern needs to be transferred to the single crystal surface or the dielectric layer to form an effective pattern window or functional pattern. This process needs to be realized by photolithography. The ordinary lithography machine needs to let the light beam pass through the mask pattern, and project it in parallel on the substrate coated with photoresist, but the cost of making the mask plate is high, and the service life is relatively short. The direct-write lithography machine directly hits the focused beam spot on the substrate coated with photoresist without going through a mask. This patent relates to a phase plate for generating a special focused spot, which can be applied to a direct-write lithography machine to generate the characters of a special focused spot. By changing the wavelength of the incident light on the phase plate, focused spots of various sizes can also be generated.

SUMMARY OF THE INVENTION

The utility model patent provides a phase plate for generating a special focus spot, the phase plate can phase modulate the incident light beam, and can generate a special focus spot without a mask. The size of the spot can be adjusted by changing the wavelength of the incident light.

的平行光入射到位相板表面，在聚焦平面可以得到特殊的聚焦光斑，光斑的像素大小为

，光斑为边长为

的正方形。A phase plate that produces a special focused light spot, its surface has a phase encoding structure, and the phase variation ranges from 0 to 2π. wavelength is

The parallel light is incident on the surface of the phase plate, and a special focusing spot can be obtained at the focusing plane. The pixel size of the spot is

, the spot is the side length of

square.

Compared with the previous technology, the shape of the focusing light spot formed by the phase plate of the utility model is complex, the pattern transfer without mask can be realized, the hardware cost is saved, and the universality is good.

Description of drawings

Figure 1 is a schematic diagram of the use of a phase plate that produces a special focused spot.

Among them: a coherent light source 1 , a collimating lens 2 , a phase plate 3 that produces a special focused spot, a convex lens 4 , and a photosensitive device 5 .

Figure 2 shows the words of the special focus spot produced on the imaging device after using the phase plate.

。Figure 3 is a phase plate that produces a special focused spot and the phase distribution on its surface. The phase range is

.

Detailed ways

The content of the present invention will be described in detail below with reference to the accompanying drawings, but the content of the present invention is not limited thereto.

Figure 1 is a schematic diagram of the use of a phase plate that produces a special focused spot. It includes a coherent light source 1 , a collimating lens 2 , a phase plate 3 that produces a special focused spot, a convex lens 4 , and a photosensitive device 5 .

，如图3所示。且平行光束充满位相板的整个入瞳；经过位相板，该平行光束的相位发生了变化；最后经过凸透镜4后，在感光器件5上形成大小为

的特殊聚焦光斑字样。所形成的聚焦光斑的像素为19.3nm。在实际的光刻机中，感光器件5所在的平面即为涂有光刻胶的衬底所在的平面。First, coherent light with a certain wavelength is emitted by the coherent light source: ultraviolet light with a wavelength of 193 nm, the coherent light emitted by the coherent light source 1 passes through the collimating lens 2 and becomes a parallel beam; then uniformly irradiates a phase that produces a special focused spot on board 3. The surface of the phase plate has a phase encoding structure, and the phase variation range is

,As shown in Figure 3. And the parallel beam fills the entire entrance pupil of the phase plate; after passing through the phase plate, the phase of the parallel beam changes; finally, after passing through the convex lens 4, a size of

The words special focus spot. The resulting focused spot has a pixel size of 19.3 nm. In an actual photolithography machine, the plane where the photosensitive device 5 is located is the plane where the substrate coated with photoresist is located.

The resulting focused spot is shown in Figure 2.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the patent rather than limitations. Those of ordinary skill in the art can make several modifications and improvements without departing from the principles of the patent. the scope of protection of this patent.

Claims (3)

1. A phase plate for producing a special focus spot, characterized in that: the phase plate for producing a special focus spot works under a specific optical system, and the optical system comprises: a coherent light source (1); a collimating lens ( 2); a phase plate (3) for generating a special focused light spot; a convex lens (4); a photosensitive device (5); the surface of the phase plate for generating a special focused light spot has a special phase encoding structure, which can make the The parallel light of the phase plate is condensed by a convex lens to form a special focused spot on the working plane. 2 . The phase plate for generating a special focus spot according to claim 1 , wherein the parallel light is coherent light, and the parallel light must fill the entire entrance pupil of a phase plate producing a special focus spot. 3 . 3. A phase plate for generating a special focusing spot according to claim 1, wherein the focusing spot is a square, and the side length of the square is 78 times the wavelength of the incident parallel light, and the pixels of the focusing spot are 0.1 times the wavelength of incident parallel light.

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