Information on developer processing (applies to buffered developer and TMAH developers)
Higher developer concentrations result in a formally higher light-sensitivity of the resist-developer system, thus minimising the required exposure intensity, reducing the development times and allowing for a high throughput in production. It must however be taken into account that an increased dark erosion is associated with stronger developers which successively attacks unexposed structures. More diluted developers provide, depending on the kind of resist, higher contrast and reduce the thickness loss in unexposed or only partly exposed interface areas even with longer development times. This particularly selective working method ensures a high degree of detail reproduction, while the intensity required for exposure is inevitably increased at the same time. To obtain a high contrast, more diluted developer and longer development times are recommended. Substrates have to be rinsed in deionised water immediately after development until complete removal of all residual developer, and are subsequently dried.
但需要留意的是, 較強的顯影劑對不顯影的光阻具有較高的蝕刻率(dark erosion). 對正型光阻而言,即強顯影劑會攻擊未曝光部份.
特別是在製程參數調整, 如果高強度曝光無可避免, 稀釋過的顯影液及拉長顯影時間可獲得較高的對比.
顯影後,基板需立即以DI water水洗以去除殘留的顯影液, 並緊接著乾燥製程.