Integrated etch, rinse and dry, and anneal method and system

#In present metal etch processing systems, one, or possibly a few large wafers are processed in an etch chamber. A cassette having several wafers is loaded at an interface of the etch system and the wafers are moved, usually by robotic arm, from the cassette to the etch chamber for processing. Thus, wafers are removed from the cassette, placed in the etch chamber, etched, and then returned to the cassette. After all the wafers of a cassette have been processed in this manner, the cassette is removed from the etch processing system and carried by an operator to a stand alone wet clean system. Typically, the entire cassette of wafers are cleaned in a wet bath and then dried in preparation for inspection and/or testing.

#A drawback with current metal etch processes is that metal structures on the surface of the wafer can degrade after removal of the cassette from an etch station. Highly reactive etch residues remaining on the surface of a wafer after an etch process can combine with gases and/or moisture of ambient atmosphere in a cleanroom to create corrosive agents on the surface of the wafer. For example, fluorine residue can combine with moisture to form hydrofluoric acid. Similarly, chlorine or bromine residues can form hydrochloric or bromic acids. Metal structures on the wafer are particularly susceptible to degradation as a result. Moreover, copper, which has advantages over other conductors in certain high performance devices, is more susceptible to corrosion than certain other conductors such as aluminum.

#Furthermore, in current state of the art metal etch process, because of the small size of the metal structures created, even small amounts of oxidation or corrosion occurring during processing can perceptibly degrade device performance. Particularly in high performance devices, any degrading of device performance can result in failure of the device, thus reducing manufacturing yields and throughput.

#FIG. 1 shows simplified plan view of an integrated etch station in accordance with an embodiment of the present invention.

#FIG. 2 shows simplified plan view of an integrated etch station in accordance with an embodiment of the present invention.

#FIG. 3 shows simplified plan view of an integrated etch station in accordance with an embodiment of the present invention.

#FIG. 1 shows an integrated metal etch, rinse and dry, and anneal station 100. A cassette or other wafer carrier 115 is mounted at a factory interface 110 of the integrated etch station 100. The factory interface opens to a transport chamber 105b of a wet clean section of the integrated etch station 100. A wet clean module 150 and an anneal module 160 are mounted to the wet clean transport chamber 105b. Plasma etch chambers 120, 130, and 140 are mounted to a preprocessing chamber 105a. Because metal etch chamber typically operates in about the 10−5 atmosphere range, pumping each wafer down from 1 atmosphere to 10−5 in a single chamber would take a long time. Thus, the etch preprocessing chamber pumps down to about 10−3 to 10−4 atmosphere to shorten pump down time in the etch chambers 120, 130 or 140. An intermediate chamber 105c, such as a pressure load lock chamber, may be located between the chambers 105b and 105a to provide an intermediate chamber between the wet clean transport chamber 105b and the etch preprocessing chamber 105a.

#Together chambers 105b, 105c, and 105a form a controlled environment passage 105 for transporting the wafers 116 within the integrated metal etch station 100. A transport system (not shown), such as a robotic arm (not shown), is located within the wet clean section chamber portion 105b to move wafers 116 to and from the cassette 115, the intermediate chamber 105b, the wet clean module 150, and the anneal module 160. The transport system may include a second robotic arm (not shown), located within the etch preprocessing chamber portion 105a for moving wafers to and from the intermediate chamber 105c and the etch chambers 120, 130, and 140.

#As depicted by the process flow arrows in FIG. 1, a wafer may be transported from the cassette 115 to one or more processing chambers 120, 130, and 140 for metal etch processing. After a wafer 116a, 116b, or 116c has been etched, it may be transported from the preprocessing chamber 105b the controlled atmosphere of the passage 105 to the wet clean module 150 without requiring an operator to carry them to a stand alone wet clean station. The wafers 116 may be wet cleaned after metal etching to remove any corrosive residues from the surface before exposing them to the ambient atmosphere. The wet clean module 150 rinses and dries the wafer 116d. After rinsing, the wafer 116d is blown dried, or spun in the wet clean module, to remove excess rinse solution from the wafer 116d.