Patent ID: 9720325
Date: 2017-08-01
CPC Classifications: B05D,G03F,H01L

Claim:
1. A method, comprising: dispensing a solvent on a wafer; rotating the wafer at a constant solvent dispersal speed after the dispensing the solvent and prior to dispensing photoresist; rotating the wafer at a constant first speed for a first time duration, wherein accelerating the wafer from the constant solvent dispersal speed to the constant first speed is performed at a constant acceleration; rotating the wafer at a second speed that is less than the constant first speed for a second time duration after the first time duration, wherein accelerating the wafer from the constant first speed to the second speed is performed at a constant acceleration; rotating the wafer at a third speed for a third time duration after the second time duration, wherein the third time duration lasts as long as the wafer is rotating at the third speed, wherein the third speed is greater than the constant first speed by between 1500 rpm and 4000 rpm; and dispensing photoresist on the wafer within the first time duration, the second time duration and throughout the third time duration.