USOO7166734B2 (12) United States Patent (10) Patent No.: US 7,166,734 B2 Shenai-Khatkhate et al. (45) Date of Patent: Jan. 23, 2007 (54) METHOD FOR MAKING 3,808.207 A 4/1974 Shepherd et al. ........... 260/247 ORGANOMETALLC COMPOUNDS 4,364,872 A 12, 1982 Diefenbach ............. 260,448 A 4,364,873. A 12/1982 Difenbach . ... 260/448 A (75) Inventors: Deodatta Vinayak Shenai-Khatkhate, i.e. A t NG et al. O's...b wk 4 C. a. - - - RNA W. East S 4,841,082. A 6/1989 Eidt et al. ......... ... 556,129 mamchyan, Wakefield, MA (US) 4,847,399 A 7/1989 Hallock et al. ................ 556.1 5,350,869 A 9/1994 Kanjolia et al. ............... 556.1 (73) Assignee: Rohm and Haas Electronic Materials 5,473,090 A 12, 1995 Smit et al. ..................... 556.1 LLC, Marlborough, MA (US) 5,543,537 A 8/1996 Eisenberg et al. ... 556,157 - 0 5,663,390 A 9, 1997 Giolando ....................... 556.1 (*) Notice: Subject to any disclaimer, the term of this 5,756,786 A 5/1998 Power et al. .. ... 556.1 patent is extended or adjusted under 35 5,817.847. A 10, 1998 Giolando ....................... 556.1 U.S.C. 154(b) by 0 days. 6,660,874 B2 12/2003 Shenai-Khatkhate et al. .. 556/70 6,680,397 B2 1/2004 Shenai-Khatkhate et al. .. 556/1 (21) Appl. No.: 11/219,227 6,770,769 B2 8, 2004 Shenai-Khatkhate et al. .. 556/1 2004/O198042 A1 10, 2004 Shanai-Khatkhate (22) Filed: Sep. 2, 2005 et al. .......................... 438,680 (65) Prior Publication Data OTHER PUBLICATIONS US 2006/OO.47 132 A1 Mar. 2, 2006 Bradley et al., Synthesis and characterization of trialkylaluminium dialkylamine adducts: X-ray diffraction and "H NMR studies; J. Related U.S. Application Data Chen. Soc., Dalton Trans., 1999, pp. 3553-3558. Eisch et al., “Organometallic Compounds of Group III. I. The (60) Provisional application No. 60/606,795, filed on Sep. Preparation of Gallium and Indium Alkyls from Organoaluminum 2, 2004. Compounds'; Journal of the American Chemical Society, vol. 84. No. 19, Oct. 177, 1962, pp. 3605-3610. (51) Int.C07F Cl. 5/06 (2006.01) Primary Examiner Porfirio Nazario-Gonzalez (52) U.S. Cl 556/187: 556/1:55.6/129: (74) Attorney, Agent, or Firm—S. Matthew Cairns 556/170 (57) ABSTRACT (58) Field of Classification Search .................... 556/1, S lication file f let R 187 Organometallic compounds of Group IIB and IIIA metals ee appl1cauon Ille Ior complete searcn n1story. that are substantially pure and contain low levels of oxy (56) References Cited genated impurities are provided. Also provided are methods of preparing such organometallic compounds. U.S. PATENT DOCUMENTS 2.954,389 A 9, 1960 Nobis et al. ................ 260/448 15 Claims, No Drawings US 7,166,734 B2 1. 2 METHOD FOR MAKING a=1–3, b is the valence of M, c=0–2, and a--c=b; having a ORGANOMETALLIC COMPOUNDS purity of 99.9999% and having less than 0.5 ppm of oxy genated impurities. This application claims the benefit of U.S. provisional Also provided by the present invention is a method of application Ser. No. 60/606,795, filed on Sep. 2, 2004. preparing the above-described compound including the steps of reacting a compound of the formula R'M1'Y', BACKGROUND OF THE INVENTION (formula 2), wherein each R" is independently a (C-Co.) organic radical, M1 is a Group IIB or IIIA metal, each Y is This invention relates generally to the field of organome independently a (C-C) carboxylate or halogen, a' 0–2, b' tallic compounds. In particular, this invention relates to the 10 is the valence of M1, c'=1-3, and a'+c'-b', with a compound preparation of organometallic compounds suitable for use in of the formula R,M2Y, (formula 3), wherein each R is vapor deposition and epitaxial growth of metal-containing independently a (C-C) organic radical, M2 is a Group films. IIIA metal, each Y is independently a (C-C) carboxylate Metal films may be deposited on surfaces by a variety of or halogen, X=1-3, in the presence of a tertiary amine or a means such as chemical vapor deposition (“CVD), physical 15 tertiary phosphine, wherein an electronegativity of M12an vapor deposition (“PVD), and other epitaxial techniques electronegativity of M2. such as liquid phase epitaxy (“LPE'), molecular beam The present invention further provides a vapor delivery epitaxy (MBE), chemical beam epitaxy (“CBE) and device including one or more of the above-described com atomic layer deposition (ALD). Chemical vapor deposi pounds. In addition, methods including one or more Group tion processes, such as metalorganic chemical vapor depo IIB or IIIA metals using the above-described compounds are sition (“MOCVD), deposit a metal layer by decomposing contemplated by this invention. organometallic compounds (often referred to as “precur sors”) at elevated temperatures, i.e., above room tempera DETAILED DESCRIPTION OF THE ture, either at atmospheric pressure or at reduced pressures. INVENTION A wide variety of metals may be deposited using such CVD 25 or MOCVD processes. As used throughout this specification, the following For semiconductor and electronic device applications, abbreviations shall have the following meanings, unless the these organometallic compounds must be highly pure and be context clearly indicates otherwise: C. degrees centigrade; substantially free of detectable levels of both metallic impu mol moles; mmol millimoles; b.p.-boiling point, g gram; rities, such as silicon and Zinc, as well as oxygenated 30 L-liter, um micron micrometer, ppm parts per million; impurities. Oxygenated impurities are typically present from ppb-parts per billion; kPa kilopascals; and mL-milliliter. the solvents, such as ethereal solvents, used to prepare such "Halogen refers to fluorine, chlorine, bromine and iodine organometallic compounds, and are also present from other and "halo' refers to fluoro, chloro, bromo and iodo. Like adventitious sources of moisture or oxygen. wise, “halogenated refers to fluorinated, chlorinated, bro Organometallic compounds of Group IIB and IIIA metals 35 minated and iodinated. “Alkyl includes linear, branched may be prepared by a variety of conventional methods. Such and cyclic alkyl. Likewise, “alkenyl and “alkynyl include methods include reacting a Group IIB or IIIA metal halide linear, branched and cyclic alkenyl and alkynyl, respec with a Grignard reagent in an ethereal Solvent, reacting an tively. “Aryl refers to any aromatic moiety, and preferably organo halide with a metal melt, and transalkylating a metal an aromatic hydrocarbon. The articles “a” and “an refer to halide using a trialkyl aluminum, among other methods. 40 the singular and the plural. As used herein, “CVD' is Transalkylation reactions, such as those disclosed in U.S. intended to include all forms of chemical vapor deposition Pat. Nos. 5,756,786, and 6,770,769 are particularly useful as such as MOCVD, MOVPE, OMVPE, OMCVD and ethereal solvents can be avoided. RPCVD. When transmethylation reactions are employed using a Unless otherwise noted, all amounts are percent by weight Group IIIA metal trihalide, such as indium trihalide, and 45 and all ratios are molar ratios. All numerical ranges are trimethyl aluminum, the reaction is not efficient with respect inclusive and combinable in any order except where it is to the methyl groups transferred. For one mole of indium clear that Such numerical ranges are constrained to add up to trihalide, three moles of trimethyl aluminum must be used. 100%. The resulting byproducts are also difficult to separate from Compounds of the formula RMY (formula 1), wherein the desired reaction product, trimethyl indium. Accordingly, 50 each R is independently a (C-C) organic radical, M is a improved methods of manufacturing Group IIB and IIIA Group IIB or IIIA metal, each Y is independently a (C-C) compounds are needed. carboxylate or halogen, a 1–3, b is the valence of M, c=0–2, and a+c=b are provided by the present invention. In one SUMMARY OF THE INVENTION embodiment, a b. Suitable groups for R include alkyl, 55 alkenyl, alkynyl and aryl. The R groups may optionally be It has been found that Group IIB and Group IIIA orga Substituted with one or more dialkylamino groups of the nometallic compounds can be prepared in high yield and in formula NR'R", wherein R' and R" are independently high purity by reacting a Group IIB or IIIA metal halide selected from (C-C)alkyl. By “substituted, it is meant compound and a Group IIIA metal alkyl compound in the that one or more hydrogens of the organic radical are presence of a tertiary amine. Typically, Such reaction is 60 replaced with a dialkylamino group. Typically, R is a carried out in a hydrocarbon Solvent. Organometallic com (C-C) alkyl group, optionally substituted with one or more pounds produced by this method are extremely pure and dialkylamino groups. Exemplary R groups include, without Substantially free of oxygenated impurities. limitation, methyl, ethyl, n-propyl, iso-propyl. n-butyl, iso The present invention provides a compound of the for butyl, tert-butyl, iso-pentyl and neo-pentyl. Such com mula RMY (formula 1) wherein each R is independently 65 pounds have at least one R group and may have more than a (C-C) organic radical, M is a Group IIB or IIIA metal, one. When a compound contains more than one R group, each Y is independently a (C-C) carboxylate or halogen, such R groups may be the same or different. Y represents a US 7,166,734 B2 3 4 (C-C) carboxylate or halogen. Exemplary carboxylates dently a (C-C) carboxylate or halogen, a'=0–2, b' is the include formate, acetate and propionate.