Method for cleaning substrates using supercritical fluids

Abstract

A method for cleaning substrates typically after a CMP process is carried out thereon. The method includes providing a cleaning chamber, providing a substrate to be cleaned in the cleaning chamber, providing the chamber at temperature and pressure conditions favorable for formation of a supercritical cleaning fluid therein, and introducing the liquid or gaseous fluid into the chamber to form the supercritical cleaning fluid therein. The supercritical fluid removes particles and residues from the substrate without causing the formation of voltage potentials which may otherwise cause galvanic corrosion of metal lines or other device features on the substrates in the case of wet-cleaning applications.

Description

FIELD OF THE INVENTION [0001] The present invention relates to methods for cleaning substrates. More particularly, the present invention relates to methods for cleaning substrates using a supercritical cleaning fluid. BACKGROUND OF THE INVENTION [0002] In the fabrication process for semiconductor devices, numerous fabrication steps, as many as several hundred, must be executed on a silicon wafer in order to complete integrated circuits on the wafer. Generally, the process for manufacturing integrated circuits on a silicon wafer substrate typically involves deposition of a thin dielectric or conductive film on the wafer using oxidation or any of a variety of chemical vapor deposition processes; formation of a circuit pattern on a layer of photoresist material by photolithography; placing a photoresist mask layer corresponding to the circuit pattern on the wafer; etching of the circuit pattern in the conductive layer on the wafer; and stripping of the photoresist mask layer from the w...

AI Technical Summary

Benefits of technology

[0015] In accordance with these and other objects and advantages, the present invention is generally directed to a new and improved method for cleaning substrates typically after a CMP process is carried out thereon. The method includes providing a cleaning chamber, providing a substrate to be cleaned in the cleaning chamber, providing the chamber at temperature and pressure conditions favorable for formation of a supercritical cleaning fluid therein, and introducing the liquid or gaseous fluid into the chamb

Problems solved by technology

Furthermore, technological advances in recent years in the increasing miniaturization of semiconductor circuits necessitate correspondingly stringent control of impurities and contaminants in the plasma process chamber.

When the circuits on a wafer are submicron in size, the smallest quantity of contaminants can significantly reduce the yield of the wafers.

For instance, the presence of particles during deposition or etching of thin films can cause voids, dislocations, or short-circuits which adversely affect performance and reliability of the devices constructed with the circuits.

The post-CMP scrubber brush method for removing particles and remaining surface defects from the surface of a planarized wafer is attended by several disadvantages, one of the foremost being that the scrubber brush has a tendency to trap and become contaminated with the larger particles removed from the wafer.

Consequently, the trapped particles may potentially become dislodged from the scrubber brush upon cleaning and planarization of a subsequent wafer.

The presence of particles in the integrated circuits compromises the functional integrity of the devices in the finished electronic product.

A common disadvantage inherent in the rinsing and drying of wafers in an SRD station is that electric potentials induce galvanic corrosion in metal lines on the wafer when copper lines on the P+ region and the N+ region behave as anode and cathode, respectively.

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