Sharp Kabushiki Kaisha Corporation

Sharp Laboratories of America, Inc

Sharp Microelectronics Technology, Inc.

Masato Kobayashi

Tue H Nguyen

Lawrence J Charneski

Yoshihide Senzaki

Bruce Dale Ulrich

Sheng Teng Hsu

A method of applying chemical vapor deposition (CVD) copper (Cu) to integrated circuit substrates using a precursor with either a dimethoxymethylvinylsilane (dmomvs), or methoxydimethylvinylsilane (modmvs), silylolefin ligand bonded to (hfac)Cu is provided. The dmomvs ligand is able to provide the electrons of oxygen atoms from two methoxy groups to improve the bond between the ligand and the (hfac)Cu complex. The improved bond helps insure that the ligand separates from the (hfac)Cu complex at consistent temperatures when Cu is to be deposited. In situations where a precursor having a smaller molecular weight is desired, the modmvs ligand is used to provide electrons from the oxygen atom of the single methoxy group. In the preferred embodiment, water vapor is added to the volatile precursor to improve the conductivity of the deposited Cu. Other embodiments provide a precursor blend made from additional silylolefins, hexafluoroacetylacetone (H-hfac), and water, either separately, or in combinations, to enhance deposition rate, conductivity, and precursor stability. A Cu precursor compound including the dmomvs and modmvs ligands with (hfac)Cu is also provided.

Precursor with (methoxy) (methyl) silylolefin ligand to deposit copper

A method of using diluted nitric acid and an edge bead removal tool to remove copper from the perimeter of a semiconductor wafer is provided. In one embodiment, sensitive areas of the wafer are covered with photoresist, and the wafer perimeter cleared of photoresist, before the acid is applied. In another embodiment, sensitive areas of the wafer are protected with water spray as the copper etchant is applied. In a third embodiment, the nitric acid is applied to clear the wafer perimeter of copper before a chemical mechanical polishing (CMP) is performed on the layer of deposited copper. The excess thickness of copper protects copper interconnection structures from reacting with the copper etchant. All these methods permit copper to be removed at a low enough temperature that copper oxides are not formed. A semiconductor wafer cleaned of copper in accordance with the above-described method, and a system for low temperature copper removal is also provided.

Semiconductor wafer with removed CVD copper

A method of enhancing copper adhesion to a substrate includes preparing a single-crystal silicon substrate; forming integrated circuit components on active areas of the substrate; metallizing the integrated circuit components, including metallizing a first copper layer by low-rate CVD, and metallizing a second copper layer by high-rate CVD; and finalizing construction of the structure.

Enhanced CVD copper adhesion by two-step deposition process

Low temperature system and method for CVD copper removal

A method is provided for applying chemical vapor deposition (CVD) copper (Cu) to integrated circuit substrates using a Cu(hfac)(ligand) precursor with a silylolefin ligand including combinations of C1-C8 alkyl groups with at least one C2-C8 alkyloxy group. The alkyloxy groups include, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, and aryloxy, while the alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and aryl. The oxygen atoms of the alkyloxy groups, and the long carbon chains of both the alkyl and alkyloxy groups, increase the stability of the precursor by contributing electrons to the Cu(hfac) complex. The improved bond helps insure that the ligand separates from the (hfac)Cu complex at consistent temperatures when Cu is to be deposited. Combinations of alkyloxy and alkyl groups allow the molecular weight of the precursor to be manipulated so that the volatility of the precursor is adjustable for specific process scenarios. Other embodiments provide a precursor blend made from additional silylolefins, hexafluoroacetylacetone (H-hfac), H-hfac dihydrate, and water, either separately, or in combinations, to enhance deposition rate, conductivity, and precursor stability. A Cu precursor compound including silylolefin ligands having at least one alkyloxy group is also provided. Combinations of ethyl groups with ethoxy groups are specifically disclosed.

Precursor with (alkyloxy)(alkyl)-silylolefin ligand to deposit copper

A method of blending water vapor with volatile Cu(hfac)TMVS (copper hexafluoroacetylacetonate trimethylvinylsilane) is provided which improves the deposition rate of Cu, without degrading the resistivity of the Cu deposited upon an integrated circuit surface. The method of the present invention uses a relatively small amount of water vapor, approximately 0.3 to 3% of the total pressure of the system in which chemical vapor deposition (CVD) Cu is applied. The method specifies the flow rates of the liquid precursor, carrier gas, and liquid water. The method also specifies the pressures of the vaporized precursor, vaporized precursor blend including carrier gas and water vapor. In addition, the temperatures of the vaporizers, chamber walls, and IC surfaces are disclosed. A Cu precursor blend is also provided comprising vaporized Cu(hfac)TMVS and water vapor. The ratio of water vapor pressure to vaporized precursor is approximately 0.5 to 5%. Further, an IC surface covered with Cu applied with a Cu precursor blend including vaporized Cu(hfac)TMVS and water vapor, with the above mentioned ratio of water vapor pressure to volatile Cu(hfac)TMVS pressure, is provided.

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Vancouver, WA, United States of America

Masato Kobayashi