EUV (extreme UV) lithographic apparatus and exposure method therefor

Abstract

An EUV photoetching device and an exposure method therefor. A mask table (300) of the device bears a plurality of reflection type masks (400a, 400b), wherein while one reflection type mask (400a) at an exposure position conducts exposure, the other reflection type mask (400b) at a measurement position can conduct facial forming and position measurement simultaneously. When a plurality of batches of silicon chips are exposed, the time for facial forming and position measurement can be saved, thereby improving the productivity. The mask table (300) can also bear a plurality of identical reflection type masks, and silicon chips are exposed by using a manner of switching masks alternately, so that by means of continuously switching the reflection type masks, the occurrence of the situation where the image quality is impaired, which is caused by the thermal deformation of the reflection type masks after being exposed for a period of time, due to the fact that heat dissipation in a high vacuum environment is difficult can be avoided.

Description

Technical field [0001] The invention relates to the field of lithography, and in particular to an EUV lithography device and an exposure method thereof. Background technique [0002] Projection exposure device is a device for projecting and exposing the circuit pattern on the mask through a projection optical system, and can project the circuit pattern on the silicon wafer for manufacturing integrated circuits at a certain magnification or reduction ratio. The development of integrated circuits follows "Moore's Law". With the rapid development of IC manufacturing technology, IC integration is gradually increasing, and the wavelength of light used by projection exposure devices is also gradually decreasing. The current mainstream photolithography technology uses 193nm (DeepUV; DUV) wavelength Laser. Driven by technological innovations such as immersion technology, double exposure and multiple exposure, it is gradually approaching the lithography limit that DUV wavelengths can rea...

AI Technical Summary

Problems solved by technology

[0007] 1. During the continuous exposure of multiple batches of EUV lithography, before the exposure of the first silicon wafer in each batch, it is necessary to exchange the mask at the exchange position, measure the mask surface at the measurement position, and then measure the mask surface at the exposure position. Exposure, especially when performing a double exposure or multiple exposure process, the switching of each mask and the measurement of the subsequent operations need to be performed serially, thus affecting the yield

[0008] 2. In the EUV high-vacuum environment, it is more difficult to dissipate heat from the mask. When a mask is continuously exposed, the mask absorbing layer is deformed due to heat, which affects the imaging quality. It is necessary to wait for cooling treatment to affect the yield

[0009] 3. The EUV lithography system is particularly sensitive to the environment. When it is necessary to use a calibration mask to calibrate the system, mask replacement and surface measurement take time and affect productivity

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