Patent ID: 9659794
Date: 2017-05-23
CPC Classifications: H01L

Claim:
1. An apparatus, comprising: a susceptor for placing a wafer; a chemical source; a first piping connected to the chemical source, wherein the chemical source is configured to deliver a chemical to the first piping, and the first piping is configured to dispense the chemical to the wafer on the susceptor; a second piping connected to the first piping; a liquid source configured to deliver a cleaning liquid to the first piping through the second piping to wash a portion of the first piping; a third piping connected to the first piping; a gas source configured to flow a purge gas to the first piping through the third piping to purge the portion of the first piping; a circulating piping configured to re-circulate the chemical, wherein two ends of the circulating piping are respectively connected to the first piping and the chemical source; and an auxiliary piping configured to replenish a flow rate of the chemical in the circulating piping, wherein two ends of the auxiliary piping are respectively connected to the first piping and the circulating piping.