AR-BR 5400series bottom resist for two-layer lift-off system

For optical transparent structure & thermal stable up to 250℃

2L-Lift-off positive System with AR-BR 5400 - AR-P 3500

This diagram shows exemplary process steps for the positive system AR-BR 5400 – AR-P 3540. All specifications are guideline values which must be adapted to own specific conditions. For further information on processing, 👉“ Detailed instructions for optimum processing of photoresists”. For recommendations on wastewater treatment and general safety instructions, 👉”General product information on Allresist photoresists”.

圖示為AR-BR 5400系列搭配AR-P 3540的雙層製程參數範例. 所有參數為參考值,使用者應依設備環境實際狀況加以調整

Processing instructions for positive two-component system


The substrate is at first coated with the co- polymer AR-BR 5400 and tempered. After cooling to room temperature, the photoresist is applied onto the copolymer. Dwell times are to be avoided; the liquid photoresist should not be left for more than 10 s on the standing wafer. The film thickness may be varied in a range between 1.6 - 4.0 μm. Subsequently, the two- component system is tempered.


基板(晶圓)上首先塗佈AR-BR 5400共聚物當底層並軟烤.待基板冷卻至室溫時塗佈正型光阻於底層之上.光阻滴定於基板後需避免延滯超過10秒. 否則膜厚變異可能介於1.6 – 4.0 um之間. 光阻塗佈後再對2層膜厚軟烤.


The ratio of film thicknesses of both films will affect structural geometry. For a strong lift-off effect, a thin photoresist layer and a thick copolymer layer is advantageous. For a dimensionally accurate transfer of structures into the copolymer layer however, both layers should have approximately the same thickness. The entire system always must be optimized for the particular application.


兩層材料膜厚比例會影響結構. 薄光阻搭配較厚的底層共聚物可獲得較好的浮剝離(lift-off)效果. 兩層材料厚度一致則底層可獲得較佳的尺寸精確度. 使用者需依實際應用調整厚度比例.


AR-P 3500: Exposure and aqueous-alkaline development are carried out as usual (👉Product information AR-P 3500). AR-BR 5400: The copolymer itself is not sensitive in the UV-range between 300-450 nm. The properties of the layer are however adjusted such that the polymer will dissolve quickly in the recommended aqueous-alkaline developer.


AR-P 3500正光阻曝光及鹼性水溶液顯影依產品基本參數. (👉請參考AR-P 3500series 產品資料)

AR-BR 5400底層共聚物對紫外線波長300-450nm不感光. 但可在光阻鹼性水溶液顯影液中快速溶解.


After the upper photoresist layer is entirely developed in exposed areas, the developer begins to dissolve the copolymer.

The dissolution process now takes place in undirected manner (isotropic).

AR-BR 5400 is in this process removed both towards the bottom and towards the left or right side so that the under-cut is formed. The longer the developer can exert its effect, the more of the copolymer under the photoresist film is removed by dissolution. For a reduction of the dissolving rate, a higher temperature of up to 180 °C must be chosen (instead of 150 °C). The desired undercut can thus be adjusted via the parameter's temperature and development time (👉see images below).


上層正光阻曝光區完全顯影後,顯影液開始溶解底層的共聚高分子. 但此時的溶解是等向性的. 即AR-BR 5400溶解的方向有向下及左右,因此型成下切結構. 顯影時間越長,底層溶解越多,下切效果越明顯. 底層材料軟烤溫度從150℃提高至180℃可降低溶解率. 因此下切結構可依軟烤溫度及顯影時間調整. (👉請參考下圖)

Selective removal of the photoresist layer (optional):

For transparent and temperature-stable films, the copolymer layer is used alone. In this case, the residual photoresist is selectively removed after development with remover AR 600-70. The substrate is briefly immersed in remover AR 600-70 and dried immediately with compressed air.


底層材料為耐溫透明結構,可依需求應用,因此光阻顯影後可單獨以AR 600-70去除. 以浸泡式將基本板置於AR 600-70去除液中並立即以壓縮空氣乾燥.

Lifting / Removal:

Removers AR 300-73 and AR 300-76 are both suitable for lifting. If lift-off structures are not thermally stressed during evaporation or sputtering, lifting will take place within a minute.

After high thermal load (> 150 °C), the time required for lifting increased considerably. Ultrasound and heating facilitate a removal. Remover AR 300-73 may in this case be heated up to 50 °C max.


AR 300-73及AR 300-76兩款去除劑都適合用於懸浮剝離的製程. 如果要被剝離的結構未受蒸鍍或濺鍍高溫影響,應該可在一分鐘之內剝離.

製程溫度如果高於150℃, 剝離所需時間會明顯增加. 可用超音波或加熱去除液改善. AR 300-73去除製程為例,最高可加熱至50℃