Patent ID: 7824505

Claim:
A method to clean a semiconductive device, the semiconductive device comprises a substrate, a device structure formed over the substrate, said device structure comprising a polysilicon layer, and an amorphous carbon mask formed over the device structure, wherein the method comprises: removing said amorphous carbon mask from said device structure by dry stripping; wetting said semiconductive device with a first liquid solution at a first temperature for a first period of time after the removal of said amorphous carbon mask, said first liquid solution having an etch-rate of less than 1 A/min for polysilicon and an etch-rate of less than 1.5 A/min for undensified TEOS, said first liquid solution consisting of phosphoric acid (H 3 PO 4 ), and said first liquid solution effective in removing interfacial carbon from said polysilicon layer of said device structure formed over the substrate; wetting said semiconductive device with a second liquid solution comprising deionized water after expiration of said first period of time for a second period of time; and spin-drying said semiconductive device after expiration of said second period of time.