Abstract: A method for coating low viscosity materials onto a wafer to form a uniform film. After a wafer is rotated at a first rotation speed, coating solution is dispensed onto the wafer. The wafer is decelerated to a second rotation speed at a first deceleration rate to spread the coating solution. Next, the wafer is slowly decelerated to a third rotation speed at a second deceleration rate considerably lower than the first deceleration rate, so the coating solution reflows to the center of the wafer. The wafer is then quickly accelerated to a fourth rotation speed at a third acceleration rate larger than the first deceleration rate to spread the coating solution again.

Abstract: A method for coating low viscosity materials onto a wafer to form a uniform film. After a wafer is rotated at a first rotation speed, coating solution is drizzled onto the wafer. The wafer is decelerated to a second rotation speed at a first deceleration rate to spread the coating solution. Next, the wafer is slowly decelerated to a third rotation speed at a second deceleration rate considerably lower than the first deceleration rate, so the coating solution reflows to the center of the wafer. The wafer is then quickly accelerated to a fourth rotation speed at a third acceleration rate larger than the first deceleration rate to spread the coating solution again.