Transmittance-adjustable half tone mask and method for manufacturing same

Abstract

The invention relates to a halftone mask plate capable of adjusting the transmission rate and a method for manufacturing the same. The halftone mask plate comprises a substrate, on which a halftone regional layer used as a halftone region and a non-transmission regional layer used as a non-transmission region are formed, and the region except the halftone regional layer and the non-transmission regional layer is a transmission regions. The halftone regional layer consists of a plurality of halftone layers and buffer layers which are alternately deposited in turn. In the same etching condition, the non-transmission regional layer, the halftone layers and the buffer layers have different etching rates. The manufacturing method comprises forming the non-transmission regional layer and the halftone regional layer. Forming the halftone regional layer is to alternately deposit the plurality of the halftone layers and the buffer layers in turn. The halftone mask plate and the method have the advantages of reducing a plurality of experiments and adjustments before the production and enhancing the production efficiency; and when the deviation of the transmission rate is larger, the halftone mask plate can change the transmission rate in accordance with requirements, so the mask plate is not needed to be remanufactured, and the production cost is reduced.

Description

technical field [0001] The invention relates to a half-tone mask and its manufacturing method, in particular to a half-tone mask with adjustable transmittance and its manufacturing method Background technique [0002] At present, the process of manufacturing a half tone (Half Tone) mask plate is to first deposit a material layer such as metal Cr on the surface of the mask plate, coat a photoresist on the surface of the Cr material layer, and remove the photoresist in the half tone area through a photolithography process. Remove the Cr layer in the half-tone area by etching process; then deposit the CrOx layer, coat photoresist on the surface of the CrOx layer, remove the photoresist except the half-tone area by photolithography process, and remove the photoresist outside the half-tone area by etching process CrOx layer so that the CrOx layer only covers halftone areas. Figure 7 It is a cross-sectional view of a halftone reticle manufactured by a conventional method. A halft...

AI Technical Summary

Problems solved by technology

The transmittance of a halftone mask is generally 30% to 50%, which is related to engineering conditions such as photoresist and light-transmitting equipment, so the transmittance cannot be set in advance

In order to determine the optimal thickness of the halftone layer, the practice in the prior art is to carry out multiple experiments before production, and constantly adjust the process parameters according to the feedback of the experimental results. As a result, the manufacturing cost of the halftone mask is sharply reduced rise

In addition, even if the transmittance of the halftone layer is adjusted by changing the thickness of the halftone layer after the reticle manufacturing process is completed, the consistency of the thickness of the halftone layer will be deteriorated, resulting in the halftone reticle being unusable

Therefore, when the transmittance of the reticle deviates greatly after the manufacturing is completed, the existing technology can only remanufacture the reticle according to the specific transmittance requirements, further exacerbating the increase in manufacturing costs

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