DD231568A1

DD231568A1 - METHOD FOR PRODUCING HIGH-PURITY GALLIUM FRIAL CYLINDERS

Info

Publication number: DD231568A1
Application number: DD27137884A
Authority: DD
Inventors: Karl-Heinz Thiele; Klaus Seidlitz
Original assignee: Tech Hochschule C Schorlemmer
Priority date: 1984-12-21
Filing date: 1984-12-21
Publication date: 1986-01-02

Abstract

Die Erfindung betrifft ein Verfahren zur Herstellung von hochreinen Galliumtrialkylen. Ziel und Aufgabe der Erfindung ist es, Galliumtrialkyle durch Umsetzung von Gallium-Magnesium-Gemischen mit Alkylhalogeniden mit guten Ausbeuten zu gewinnen. Erfindungsgemaess wird das dadurch erreicht, dass das Gallium-Magnesium-Gemisch vor der Reaktion mit metallischem Quecksilber aktiviert wird. Das Molverhaeltnis Gallium:Magnesium:Quecksilber betraegt dabei 1:3:0,02. Die nach dem erfindungsgemaessen Verfahren hergestellten Verbindungen weisen eine hohe Reinheit auf und sind besonders fuer die Herstellung von Halbleitermaterialien und fuer epitaktische Zwecke in der Mikroelektronik geeignet.The invention relates to a process for the preparation of high purity gallium trialkyls. The aim and object of the invention is to win Galliumtrialkyle by reaction of gallium-magnesium mixtures with alkyl halides in good yields. According to the invention, this is achieved by activating the gallium-magnesium mixture before reacting with metallic mercury. The molar ratio of gallium: magnesium: mercury is 1: 3: 0.02. The compounds prepared by the process according to the invention have a high purity and are particularly suitable for the production of semiconductor materials and for epitaxial purposes in microelectronics.

Description

Anwendungsgebiet der ErfindungField of application of the invention

Die Erfindung betrifft ein Verfahren zur Herstellung von Galliumtrialkylen. Die nach denn Verfahren gewonnenen Verbindungen weisen eine hohe Reinheit auf und sind besonders geeignet für einen Einsatz in der Mikroelektronik und Halbleiterindustrie.The invention relates to a process for the preparation of Galliumtrialkylen. The compounds obtained by the method have a high purity and are particularly suitable for use in the microelectronics and semiconductor industries.

Charakteristik der bekannten technischen Lösungen Für die Herstellung von Galliumtrialkylen sind eine Reihe von Verfahren bekannt, wobei die geforderte Reinheit der Verbindungen entscheidend ist für die Wahl des jeweiligen Verfahrens. Besonders reine Galliumtrialkyle lassen sich aus Gallium und Quecksilberdialkylen gewinnen, doch ist dieses Verfahren wegen der hohen Toxizität derOrganoquecksilberverbindungen für die Praxis wenig geeignet; außerdem bereitet die Abtrennung kleiner Anteile an Quecksilberdialkylen erhebliche Schwierigkeiten. Durch Reaktion von Gallium-Magnesium-Legierungen, vorzugsweise der Zusammensetzung Ga:Mg = 1:3mit Alkylhalogeniden in Lösungsmitteln mit Donoreigenschaften lassen sich ebenfalls Galliumtrialkyle erhalten (SU-PS 388563). Das Erschmelzen dieser Legierungen unter anaeroben Bedingungen ist jedoch mit einem beträchtlichen Aufwand verbunden und führt zu zusätzlichen Verunreinigungen, z. B. durch Metallspuren oder Carbide, bei Verwendung von Edelstahl oder Graphit als Tiegelmaterial. Weiterhin können Galliumtrialkyle durch Umsetzung von Galliumtrichlorid mit Aluminiumtrialkylen, Zinkdialkylen oder Alkylmagnesiumhaiogeniden erhalten werden (SU-PS 375293, SU-PS 417429). So erhaltene Galliumtrialkyle enthalten jedoch stets kleinere Anteile des jeweiligen Alkylierungsmittels. Angaben über ein Verfahren zur Synthese von Trimethylgailium durch Umsetzung eines Gallium-Magnesium-Gemisches (Ga:Mg = 1:3) mit Methyliodid in Dibutylether als Reaktionsmedium (SU-PS 388563) waren nach anderen Literaturangaben (A.C. Jones, A. K. Holliday u.a., J.ehern. Soc., Dalton Trans. 6,1047 [1983]) nicht reproduzierbar, was auch durch eigeneVersuche bestätigt wurde.Characteristic of the known technical solutions A number of processes are known for the production of gallium trialkyls, the required purity of the compounds being decisive for the choice of the respective process. Particularly pure gallium trialkyls can be obtained from gallium and mercury dialkylene, but this method is not very practical because of the high toxicity of the organomercury compounds; In addition, the separation of small amounts of mercury dialkylene prepares considerable difficulties. By reaction of gallium-magnesium alloys, preferably of the composition Ga: Mg = 1: 3 with alkyl halides in solvents having donor properties, gallium trialkyls can also be obtained (SU Pat. No. 388563). However, the melting of these alloys under anaerobic conditions is associated with a considerable effort and leads to additional impurities, eg. As by metal traces or carbides, when using stainless steel or graphite as crucible material. Furthermore, gallium trialkyls can be obtained by reacting gallium trichloride with aluminum trialkyls, zinc dialkyls or alkylmagnesium halides (SU-PS 375293, SU-PS 417429). However, galliumtrialkyls obtained in this way always contain smaller amounts of the respective alkylating agent. Information on a process for the synthesis of trimethylgailium by reacting a gallium-magnesium mixture (Ga: Mg = 1: 3) with methyl iodide in dibutyl ether as a reaction medium (SU-PS 388563) were according to other references (AC Jones, AK Holliday et al., J Soc., Dalton Trans. 6, 1047 [1983]) was not reproducible, which was confirmed by own experiments.

Ziel der ErfindungObject of the invention

Das Ziel der Erfindung ist es, ein Verfahren zur Gewinnung von hochreinen Galliumtrialkylen mit guten Ausbeuten zu entwickeln. Darlegung des Wesens der ErfindungThe object of the invention is to develop a process for obtaining high purity gallium trialkyls in good yields. Explanation of the essence of the invention

Aufgabe der Erfindung ist es, ein neues Verfahren zur Gewinnung von hochreinen Galliumtrialkylen aus Gallium-Magnesium-Systemen und Alkylhalogeniden zu entwickeln.The object of the invention is to develop a novel process for the recovery of high purity Galliumtrialkylen from gallium-magnesium systems and alkyl halides.

Erfindungsgemäß wird die Aufgabe dadurch gelöst, daß Gallium-Magnesium-Gemische vor der Reaktion mit metallischem Quecksilber aktiviert werden. Das Molverhältnis von Gallium:Magnesium:Quecksilber beträgt dabei 1:3:0,02. Die Reaktionstemperatur bei der Aktivierung liegtim Bereich von 100 bis300°C. Während ohne die Aktivierung bei der Behandlung des Metallgemisches mit Alkylhalogeniden und Zusatz von Ethern keine oder nur geringe Mengen an Galliumtrialkylen entstehen, reagiert das aktivierte Gemisch bereits bei Zimmertemperatur. Durch Erwärmen des Reaktionsgemisches auf eine Temperatur von 50-120°C wird daseingesetzte Gallium nahezu quantitativ umgesetzt. Nach bekannter Aufarbeitung des Reaktionsgemisches lassen sich die gewünschten Galliumtrialkyle in Ausbeuten von 70-85% isolieren.According to the invention the object is achieved in that gallium-magnesium mixtures are activated before the reaction with metallic mercury. The molar ratio of gallium: magnesium: mercury is 1: 3: 0.02. The reaction temperature in the activation is in the range of 100 to 300 ° C. Whereas no activation or only small amounts of gallium trialkyls are formed during the treatment of the metal mixture with alkyl halides and addition of ethers, the activated mixture already reacts at room temperature. By heating the reaction mixture to a temperature of 50-120 ° C, the gallium used is reacted almost quantitatively. After known work-up of the reaction mixture, the desired Galliumtrialkyle can be isolated in yields of 70-85%.

Durch die Aktivierung mit Quecksilber wird keine Verunreinigung der Galliumtrialkyle bewirkt. Der ermittelte Quecksilbergehalt lag unterhalb von 0,1 ppm. Durch Anwendung des erfindungsgemäßen Verfahrens lassen sich mehrere Vorteile erreichen. Es entfällt das aufwendige Erschmelzen von Gallium-Magnesium-Legierungen, welches zugleich eine Quelle für zusätzliche Verunreinigungen darstellt, außerdem ist bei Verwendung von hochreinen Gallium die Reinheit der erhältlichen Galliumtrialkyle höher als bei der Herstellung nach anderen Verfahren.Activation with mercury does not cause contamination of the gallium trialkyls. The determined mercury content was below 0.1 ppm. By applying the method according to the invention, several advantages can be achieved. It eliminates the costly melting of gallium-magnesium alloys, which is also a source of additional impurities, also, when using high-purity gallium, the purity of the available Galliumtrialkyle higher than in the preparation by other methods.

Ausführungsbeispieleembodiments

Beispiel 1:Example 1:

Trimethylgailium 30 g (0,43 Mol) Gallium, 32 g (1,32 Mol) trockenes Magnesiumpulver und 2,5 g (0,012 Mol) Quecksilber werden unter Rühren 4 Stunden lange auf eine Temperatur von 250°C erhitzt. Nach Abkühlung des Metallgemisches gibt man von insgesamt 190 g (1,2 Mol) Diisoamylether soviel in das Reaktionsgefäß, daß das Metallgemisch gerade bedeckt ist und tropft danach 270g (1,9 Mol) Methyliodid, verdünnt durch den Rest des Diisoamylethers, mit einer solchen Geschwindigkeit hinzu, daß dieTrimethylgailium 30 g (0.43 mol) of gallium, 32 g (1.32 mol) of dry magnesium powder and 2.5 g (0.012 mol) of mercury are heated with stirring for 4 hours to a temperature of 250 ° C. After cooling the metal mixture is added from a total of 190 g (1.2 mol) of diisoamyl in the reaction vessel that the metal mixture is just covered and then dripping 270g (1.9 mol) of methyl iodide, diluted by the rest of Diisoamylethers, with such Speed that the

Reaktionstemperatur zwischen 60 und 80°C liegt. Nach beendeter Zugabe erhitzt man noch 8 Stunden lang auf eine Temperatur von ca. 100°C. Anschließend destilliert mm das Trimethylgailium aus dem Reaktionsgefäß bei einer Badtemperaturvon 150 bis 190°C ab. - Nach fraktionierter Destillation des Rohrproduktes werden ca. 37 g (75%) Trimethylgailium erhalten. (Kp 55,7°C). Beispiel 2:Reaction temperature between 60 and 80 ° C is. After completion of the addition, the mixture is heated for 8 hours to a temperature of about 100 ° C. Then, the trimethylgailium is distilled from the reaction vessel at a bath temperature of 150 to 190 ° C. After fractional distillation of the tubular product, about 37 g (75%) of trimethylgailium are obtained. (Bp 55.7 ° C). Example 2:

Triethylgallium 62 g eines Gallium-Magnesium-Gemisches (0,43 Mol Ga und 1,32 Mol Mg) werden mit 2,5 g (0,012 Mol) Quecksilber bei einer Temperatur von 250°C 4 Stunden lang gerührt. Das abgekühlte amalgamierte Metallgemisch wird mit trockenem Diethylether bedeckt und tropfenweise mit einem Gemisch aus 302g (1,93 Mol) Ethyliodid und 150ml Diethylether mit einer solchen Geschwindigkeit versetzt, daß der Ether schwach siedet. Nach beendeter Reaktion, erkennbar am fast völligen Verbrauch des Galliums wird der Diethylether und danach das Triethylgallium aus dem Reaktionsgefäß abdestilliert. Nach fraktionierter Destillation des Rohproduktes werden 53,9g (80%) reines Triethylgallium erhalten. (Kp 142°C).Triethylgallium 62 g of a gallium-magnesium mixture (0.43 mol of Ga and 1.32 mol of Mg) are stirred with 2.5 g (0.012 mol) of mercury at a temperature of 250 ° C for 4 hours. The cooled amalgamated metal mixture is covered with dry diethyl ether and treated dropwise with a mixture of 302 g (1.93 mol) of ethyl iodide and 150 ml of diethyl ether at such a rate that the ether boils gently. After completion of the reaction, recognizable by the almost complete consumption of gallium, the diethyl ether and then the triethylgallium is distilled off from the reaction vessel. After fractional distillation of the crude product, 53.9 g (80%) of pure triethylgallium are obtained. (Bp 142 ° C).

Claims

Invention claim:

1. A process for the preparation of high purity Galliumtrialkylen by reacting gallium-magnesium systems with alkyl halides in ethers as reaction medium, characterized in that mixtures of gallium and Magnesiumrvor the reaction with metallic mercury at temperatures between 100 and 300 ⁰ C are activated.

2. The method according to item!, Characterized in that the molar ratio of gallium! Magnesium: mercury is preferably 1: 3: 0.02.

Field of application of the invention

The invention relates to a process for the preparation of Galliumtrialkylen. The compounds obtained by the process have a high purity and are particularly suitable for use in the microelectronics and semiconductor industry.

Characteristic of the known technical solutions

For the production of Galliumtrialkylen a number of methods are known, the required purity of the compounds is crucial to the choice of the respective method. Particularly pure gallium trialkyls can be obtained from gallium and mercury dialkylene, but this method is not very suitable in practice because of the high toxicity of the organomercury compounds; In addition, the separation of small amounts of mercury dialkylene prepares considerable difficulties. By reaction of gallium-magnesium alloys, preferably the composition Ga: Mg = 1: 3 with alkyl halides in solvents having donor properties can also be obtained gallium trialkyls (SU-PS 388563). However, the melting of these alloys under anaerobic conditions is associated with a considerable effort and leads to additional impurities, eg. As by metal traces or carbides, when using stainless steel or graphite as crucible material. Furthermore, gallium trialkyls can be obtained by reacting gallium trichloride with aluminum trialkyls, zinc dialkylenes or alkylmagnesium halides (SU-PS 375293, SU-PS 417429). However, galliumtrialkyls obtained in this way always contain smaller amounts of the respective alkylating agent. Information on a method for the synthesis of trimethylgailium by reacting a gallium-magnesium mixture (Ga: Mg = 1: 3) with methyl iodide in dibutyl ether as a reaction medium (SU-PS 388563) were according to other references (AC Jones, AK Holliday et al., J Chem. Soc., Dalton Trans. 6, 1047 [1983]) was not reproducible, which was also confirmed by our own experiments.

Object of the invention

The object of the invention is to develop a process for obtaining high purity gallium trialkyls in good yields. Explanation of the essence of the invention

The object of the invention is to develop a novel process for the recovery of high purity Galliumtrialkylen from gallium-magnesium systems and alkyl halides.

According to the invention the object is achieved in that gallium-magnesium mixtures are activated before the reaction with metallic mercury. The molar ratio of gallium: magnesium: mercury is 1: 3: 0.02. The reaction temperature in the activation is in the range of 100 to 300 ^° C. While no or only small amounts of gallium trialkyls are formed without the activation in the treatment of the metal mixture with alkyl halides and addition of ethers, the activated mixture already reacts at room temperature. By heating the reaction mixture to a temperature of 50-120 ° C, the gallium used is reacted almost quantitatively. After known work-up of the reaction mixture, the desired Galliumtrialkyle can be isolated in yields of 70-85%.

Activation with mercury does not cause contamination of the gallium trialkyls. The determined mercury content was below 0.1 ppm. By applying the method according to the invention, several advantages can be achieved. It eliminates the costly melting of gallium-magnesium alloys, which is also a source of additional impurities, also, when using high-purity gallium, the purity of the available Galliumtrialkyle higher than in the preparation by other methods.

embodiments
Example 1:

Trimethylgailium

30 g (0.43 mol) of gallium, 32 g (1.32 mol) of dry magnesium powder and 2.5 g (0.012 mol) of mercury are heated with stirring for 4 hours to a temperature of 250 ⁰ C. After cooling the metal mixture is added from a total of 190 g (1.2 mol) of diisoamyl in the reaction vessel that the metal mixture is just covered and then dripping 270g (1.9 mol) of methyl iodide, diluted by the rest of Diisoamylethers, with such Add speed that the reaction temperature between 60 and 8O ⁰ C. After completion of the addition is heated for 8 hours at a temperature of about 100 ⁰ C. Subsequently, the distilled min Trimethylgailium from the reaction vessel at a bath temperature of 150 to 19O ⁰ C from. After fractional distillation of the tube product, about 37 g (75%) of trimethylgailium are obtained. (Bp 55.7 ° C).

Example 2:

triethyl

62 g of a gallium-magnesium mixture (0.43 mol of Ga and 1.32 mol of Mg) are stirred with 2.5 g (0.012 mol) of mercury at a temperature of 250 ⁰ C for 4 hours. The cooled amalgamated metal mixture is covered with dry diethyl ether and treated dropwise with a mixture of 302 g (1.93 mol) of ethyl iodide and 150 ml of diethyl ether at such a rate that the ether boils gently. After completion of the reaction, recognizable by the almost complete consumption of gallium, the diethyl ether and then the triethylgallium is distilled off from the reaction vessel. After fractional distillation of the crude product, 53.9 g (80%) of pure triethylgallium are obtained. (Bp 142 ° C).