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The challenges, mask manufacturing is faced with, are more and more dominating the semiconductor industry as the pattern sizes shrink. Today's mask patterns have reached sizes that are common in wafer manufacturing. Looking into the industry, we can see that some of the quality parameters -such as CD uniformity and defect control -are managed better in wafer than in mask manufacturing. Consequently, mask manufacturers have started to apply more wafer processing techniques to mask processes. Among others, develop process has a great impact on the quality of the mask manufacturing. This contribution describes how Tokyo Electron Limited (TEL) scanning (linear drive nozzle) developer processing (widely used in advanced wafer manufacturing) was adapted for mask development. Out of this technology transfer, a new alpha-type mask develop tool was launched at TEL and an evaluation of this tool was carried out at the Advanced Mask Technology Center (AMTC), Dresden, Germany. Target of this collaboration was to successfully transfer wafer processing technology to mask making. By this, valuable information was generated, that has been implemented into the production platform, which is commercialized since first half of 2004.

A new photomask develop tool designed by Tokyo Electron Limited (TEL) with wafer puddle technology was evaluated at the Advanced Mask Technology Center (AMTC) in Dresden, Germany. Parameters selected for this evaluation were resist dark loss uniformity, critical dimension (CD) uniformity, loading, linearity, resist cross sectional images, and defects using chemically amplified resists (CARs) exposed with DUV (λ=257nm) and 50KeV e-beam pattern generators. Implementing wafer puddle technology to photomask developing was not a simple, straightforward process. Standard CAR puddle recipes for wafer developing were inadequate to match CDU requirements for photomasks at the 130nm technology node using DUV exposure. While the results were disappointing, the TEL alpha develop tool cannot be held entirely responsible. Other, non-develop tool related factors such as resist, substrate, coating bake temperature and time, lithography tool, and post exposure bake temperature and time, all contributed to the final post develop results. Indeed, other CAR/substrate combinations exposed at 50keV e-beam and processed on the TEL alpha develop tool were markedly better in CD performance when compared to DUV results. The AMTC has recently taken delivery of a full scale, production worthy, TEL photomask develop tool for use at future technology nodes.

Laser lithography tools have been a staple in the photomask industry for second level printing for several years. This paper explores the overlay capabilities of the Alta4300D Deep UV (DUV) lithography system. The tool is manufactured by ETEC Systems, a part of the Mask Business Group of Applied Materials. The tool demonstrates good overlay performance, and an improved data path ensures the ability to handle large file sizes without an adverse impact on writing time. In addition to actual performance data on product masks, a simple analysis of the maximum total edge placement error of a hypothetical two level alt-PSM process is presented. The results show the tool is capable for many advanced phase shift overlay applications.