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Removal of copper oxides from integrated interconnectsRelated Patent Categories: Semiconductor Device Manufacturing: Process, Chemical Etching, Vapor Phase Etching (i.e., Dry Etching)Removal of copper oxides from integrated interconnects description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060211251, Removal of copper oxides from integrated interconnects. Brief Patent Description - Full Patent Description - Patent Application Claims
REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of U.S. application Ser. No. 10/404,396, filed Mar. 31, 2003, which is a continuation of U.S. application Ser. No. 09/888,845, filed Jun. 25, 2001(now U.S. Pat. No. 6,579,803), which is a divisional of U.S. application Ser. No. 09/484,683, filed Jan. 17, 2000(now U.S. Pat. No. 6,348,125). BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to manufacturing of integrated circuits. In particular, this invention relates to the removal of copper oxides from integrated interconnects by utilizing a high intensity UV light source. [0004] 2. Description of the Related Art [0005] Copper thin films are currently being used as interconnection materials in semiconductor manufacturing. As compared to aluminum, a traditionally used material, copper has more advantages which are critical for improving integrated circuit performance. First, copper has a much lower sheet resistivity than aluminum. Thus, for carrying the same amount of current flow, a copper line can be made narrower and thinner than a line made of aluminum. Using copper, then, allows for a higher integration density. Also, narrower and thinner conductive lines decrease the inter-level and inter-line capacitance, which leads to a higher speed and less cross-talk for the circuit. Moreover, copper has a better electromigration resistance than aluminum. Therefore, as metal lines are made thinner and circuitry becomes more densely packed, copper provides higher reliability when used in integrated circuits. [0006] Typically, several interconnect levels are employed in an integrated circuit. Low contact resistance, also known as via resistance, to and between interconnection levels is required. [0007] However, during fabrication processes, a copper surface readily oxidizes even in the air, forming copper oxides, such us Cu.sub.2O and CuO. These oxides form a high resistance layer between two interlevel copper lines, which, as known by those skilled in the art, would slow down the circuit significantly. [0008] It is necessary to remove the insulating oxide layer from the copper surface before making a connection with a subsequent copper layer. SUMMARY OF THE INVENTION [0009] It is thus an objective of the present invention to provide a device which can be used to efficiently remove oxides from a copper surface. It is another objective of the present invention to provide a copper oxide removal process by using the device, and integrating the process into manufacturing of interconnect levels. [0010] In accordance with one aspect of the present invention, the device for removing copper oxide is a semiconductor reaction chamber which comprises a high intensity UV light source, a means for holding one or more semiconductor wafers inside the chamber, and a means for providing a non-oxidation environment in the chamber. [0011] The high intensity UV light source is made of at least one array of high pressure, hollow cathode microdischarge devices which are fabricated on a semiconductor wafer. The UV light source radiates light with a wavelength preferably lower than 468 nm, to photoreduce the copper oxide on the semiconductor wafer. The total area of the light source is preferably larger than the wafer area being processed. [0012] The reaction chamber can be made either as a single wafer or a multiple wafer chamber. The wafer holding means is preferably a moving part, so that the copper oxides can be uniformly photoreduced across the wafer or wafers. [0013] In order to prevent the copper surface from further oxidation, a non-oxidizing environment is obtained by flowing a non-oxidizing gas during the photoreduction process. The gas can be selected from hydrogen, ammonia, nitrogen, neon, or other non-oxidizing gases. BRIEF DESCRIPTION OF THE DRAWINGS [0014] The present invention may be best understood through the following description with reference to the accompanying drawings, in which: [0015] FIG. 1 is a table from the study of Fleisch et al, listing eight metal oxides and whether they can be UV photo reduced; [0016] FIG. 2 shows a chart also from the study of Fleisch et al, which displays oxide reduction as a function of UV radiation time by comparing copper oxides with the other metal oxide; [0017] FIG. 3 illustrates a cross section of a single microdischarge device in silicon from the study of J. W. Frame et al; [0018] FIG. 4 illustrates the reaction chamber of the present invention for photoreducing copper oxides from a semiconductor wafer; [0019] FIG. 5a shows a cross section of one embodiment illustrating an array of microdischarge devices fabricated on a silicon wafer; [0020] FIG. 5b shows a cross section of another embodiment illustrating an array of microdischarge devices fabricated on a silicon wafer; Continue reading about Removal of copper oxides from integrated interconnects... Full patent description for Removal of copper oxides from integrated interconnects Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Removal of copper oxides from integrated interconnects patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Removal of copper oxides from integrated interconnects or other areas of interest. ### Previous Patent Application: Scratch reduction for chemical mechanical polishing Next Patent Application: Apparatus and method for modifying an object Industry Class: Semiconductor device manufacturing: process ### FreshPatents.com Support Thank you for viewing the Removal of copper oxides from integrated interconnects patent info. IP-related news and info Results in 0.74212 seconds Other interesting Feshpatents.com categories: Canon USA , Celera Genomics , Cephalon, Inc. , Cingular Wireless , Clorox , Colgate-Palmolive , Corning , Cymer , 174 |
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