Alignment system of mask aligner

The manufacturing of high-precision alignment system needs nearly perfect precision mechanical technology, which is also one of the technical difficulties that domestic mask aligner can match. Many American and German brands of mask aligner have special patented mechanical process design. Such as mycon &；; Q mask aligner adopts the patented technology of all-pneumatic bearing design, which effectively avoids the process error caused by mechanical friction of bearings.

Another technical problem of the alignment system is the alignment microscope. In order to enhance the vision of microscope, many high-end mask aligner adopt LED lighting.

There are two sets of alignment systems with focusing function. Mainly 1 uses binocular double-field alignment for microscope body, eyepiece and objective lens (mask aligner usually provides eyepieces and objective lenses with different magnifications for users to combine).

The function of CCD alignment system is to enlarge the alignment marks between the mask and the sample and image them on the monitor.

As the name implies, the workpiece table is a platform for placing workpieces, and the most important workpieces in lithography process are mask and substrate.

Worktable is the key component of mask aligner, which consists of mask sample moving table (XY), mask sample relative moving table (XY), rotating table, sample leveling mechanism, sample focusing mechanism, wafer bearing table, mask fixture and drawing mask table.

Wherein, the sample leveling mechanism comprises a ball seat and a hemisphere. In the leveling process, pressurized air is first introduced into the ball seat and hemisphere, then the ball seat, hemisphere and sample are moved upward by the focusing handwheel to make the sample close to the mask to level the sample, and then the two-position three-way solenoid valve is switched to vacuum to lock the ball seat and hemisphere to keep the leveling state.

The sample focusing mechanism consists of focusing handwheel, lever mechanism and ascending linear guide rail. In the process of leveling, the initial focus is focused. After leveling, there will be a certain gap between the sample and the mask, so it is necessary to fine-tune the focus. On the other hand, after leveling, it is necessary to separate a certain alignment gap and fine-tune the focus.

The mask table is mainly used for quick loading and unloading, and consists of dovetail guide rail, positioning stop and locking handwheel.

The wafer stage and mask holder are designed according to different sample and mask sizes.