Process instruction

The sensitivity of the resist increases with increasing soft-bake temperature due to the more intense formation of anhydrides of the methacrylic acid under separation of water (diagram dose vs. soft-bake temperature). AR-P 617 tempered at 200 °C is therefore about 20 % more sensitive as compared to a tempering at 180 °C. The dose can be adjusted accordingly, which is of major importance for two-layer systems with two layers of AR-P 617. In this case, at first the bottom layer is dried at 200 °C and then tempered at 180 °C together with the upper film.

Due to differentiation processes, the lower layer is attacked faster by the developer and pronounced undercut structures are formed (lift-off). These lift-off structures can also be produced with the two-layer system PMMA/ copolymer. At first AR-P 617 is coated and tempered at 190 °C, then the PMMA resist AR-P 679.03 is applied by spin-coating and dried at 150 °C. After exposure, both layers are developed in one step e.g. with AR 600-56, treated with stopper AR 600-60 and rinsed.

阻劑共聚物中相鄰的甲基丙烯酸(methacrylic acid)在軟考溫度增加時因脫水反應更容易形成酸酐,(請參考下圖曝光劑量與軟烤溫度). AR-P 617的敏感度在200℃軟烤溫度比180℃高出20%. 曝光劑量可依此調整.同時這性質在雙層結構中是很重要的參數. 一般程序是第一層先以200℃軟烤, 塗佈第二層後再以180℃同時對兩層阻劑軟烤. 顯影劑對第一層反應較快因而形成下切型結構適合懸浮剝離製程(左下圖). 也可採用PMMA/AR-617雙層結構. AR-P 617.06先以190℃軟烤,塗佈PMMA AR-P 679.06後以150℃軟烤. 雙層阻劑曝光後以AR 600-56顯影(右下圖).