A photolithography apparatus and method

Abstract

The invention provides lithographic equipment and a method. An illumination switching mechanism is additionally arranged between an illumination system and a mask plate. During the alignment process, an illumination x-ray machine structure in the illumination switching mechanism is placed below the illumination system, and the illumination x-ray machine structure is used for attenuating, outputting and splitting the illumination light so as to enable the illumination light to only irradiate a reference mark to be aligned with the reference mark. During the exposure process, a light shading plate in the illumination switching mechanism is placed below the illumination system, so that the illumination light is only enabled to irradiate an exposure pattern area on the mask plate. In this way, no pattern of the reference mark remains on a silicon wafer after the exposure process. In addition, the side length of the common overlay area of several fields of view is adopted as a maximum side length for an incident light aperture of the illumination x-ray machine structure. In this way, in different fields of view, the light is prevented from irradiating the non-exposure pattern area of the mask plate due to the stray condition of the light. Therefore, the alignment and the exposure are conducted by using the same illumination light source. Meanwhile, the equipment is compatible with the process requirements in different fields of view. Moreover, the purposes of reducing the working time, saving the manpower and saving the cost are realized.

Description

technical field [0001] The present invention relates to a device and method, in particular to a photolithography device and method. Background technique [0002] In the manufacturing process of semiconductor integrated circuits, a complete chip usually requires multiple photolithography exposures to complete. In each photolithography, the pattern drawn on the mask plate is imaged to the surface of the object to be exposed coated with photosensitive materials such as photoresist through a projection exposure device. The device used for projection exposure needs to align the mask pattern area with the position of the object to be exposed before exposure. Usually, an alignment mark for alignment measurement is provided near the mask pattern area. Through a certain mask The alignment device and the corresponding alignment algorithm establish the relative positional relationship between the mask pattern area and the object to be exposed. [0003] In the traditional process, the...

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Problems solved by technology

[0003] In the traditional process, the illumination light intensity required for mask alignment is much smaller than the illumination requirement for exposure, so the illumination light source used in mask alignment and mask exposure is often different, and the light wavelength and the like are caused by different illumination sources. The optical data will change, and due to the existence of the glass layer thickness tolerance (6.35±0.1mm), after the optical data changes, the alignment image data will also change, so it is very likely that the mask plate has been aligned during alignment , but during exposure, when the light source is switched to the exposure light source, it is found that the originally aligned mask plate is not aligned with the workpiece stage reference, resulting in a corresponding error

[0004] In addition, with the customer's pursuit of productivity, the demand for a large field of view exposure area (53.5mm*33mm) is put forward, which makes the space limitation of the mask plane alignment device layout more prominent.

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