Specific Process Knowledge/Lithography/Coaters: Difference between revisions
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=Spin coating= | =Spin coating= | ||
The typical spin coating process consists of the following steps: | The typical spin coating process consists of the following steps: | ||
#Priming (typically HMDS) | #Priming (typically HMDS) followed by cooling to room temperature | ||
#Resist dispense (static or dynamic) | #Resist dispense (rotation: static or dynamic rotation)(arm: stationary or moving) | ||
#*Optional: Acceleration to a low spin speed if dynamic dispense is used | #*Optional: Acceleration to a low spin speed if dynamic dispense is used | ||
#*Optional: Resist spreading at low spin speed | #*Optional: Resist spreading at low spin speed for spreading thicker resists | ||
#Spin-off | #Spin-off | ||
#Backside rinse (typically during spin-off) | #Backside rinse (typically during spin-off) | ||
#Optional: Edge-bead removal | #Optional: Edge-bead removal | ||
#Softbake (contact or proximity) | #Softbake (contact or proximity) | ||
#Cooling to room temperature | |||
After priming, the wafer is | After priming, the wafer is cooled to room temperature and then transferred to the spin coater. If static dispense is used, the wafer is not rotating during the resist dispense. In the case of dynamic dispense, the wafer rotates at low spin speed during the dispense. The dispense arm is normally stationary during dispense, but some substrates may require the arm to move slowly across the substrate area while dispensing. Moving arm dispensing is usually only done with a rotating substrate. | ||
Using too high spin speed during dispense can cause surface wetting issues, while a too low spin speed causes the resist to flow onto the backside of the wafer. After dispense, a short spin at low spin speed may be used in order to spread the resist over the wafer surface before spin-off. | |||
==Spin-off== | ==Spin-off== | ||