Mask layout and exposing method for reducing diffraction effects by using a single mask in the process of semiconductor production

Abstract

The present invention discloses appropriate layout design of a single mask and proper operation of exposing device in the process of semiconductor production for reducing diffraction effects caused by tiny pattern in exposing process, therefore effectively enhances the resolution in exposing process, and increases the yield.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a mask layout and exposing device in the process of semiconductor production, and more particularly to a symmetrical layout using pattern of a single mask and the method of the same. [0003] 2. Description of the Prior Art [0004] During the last decade, due to the prospering wireless communication industry, the band of electromagnetic wave used has reached that of microwave, 1 GHz˜300 GHz. And under the trend of minimization of products, the need of microwave elements, such as filter, surface acoustic wave device, and spiral inductor on some active elements, has increased. With the aid of fast-developing technique of semiconductor production, the trend drives on the mass production and low price of microwave elements, matching the elements with the commercial demand at a high speed. However, as the frequency range of microwave elements increases, concerning product integration and cos...

AI Technical Summary

Benefits of technology

This approach effectively reduces diffraction effects, improves pattern alignment, and increases product yield by allowing the production of smaller linewidth IDT patterns using existing equipment, addressing the limitations of prior methods while maintaining efficient production cycles.

Problems solved by technology

However, as the frequency range of microwave elements increases, concerning product integration and cost of production equipment, there are some lithography problems encountered in the process of microwave element production.

The most difficult one is diffraction effects produced in exposing process.

It will result in organic residue or incomplete shape of overhang or T-Top after development process, and thus affects following lift-off process.

The organic residue may cause poor adhesion of thin film, such that the metal film peels off easily.

The lift-off may be incomplete and thus causes residual metal film.

In these situations, the elements will have short circuits or incomplete contacts, and thus become failure products.

In semiconductor industry, it is very common to fabricate 0.4 μm (even lower) linewidth device by using advanced stepper, but it is very difficult to justify to invest such expensive stepper for economically manufacturing SAW devices.

However, when to produce a SAW filter having the center frequency of 2.5 GHz by I-Line stepper, there will be diffraction effects in the exposure, so decreases the yield of products.

After the wafer stage moved lot of shots for the exposure of first part and returned to starting position for the exposure of second part, there is still inaccuracy of displacement in the practical operation of exposer.

Consequently, in the process of FIG. 1a, when the patterns of first and second parts are exposed, it is very difficult to control their relative overlaying positions.

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