US 4,772,296 AGranted

Method of purifying and depositing group IIIa and group Va compounds to produce epitaxial films

AssigneeEagle-Picher Industries, Inc.

InventorThomas M. Potts

Life of this patent

Estimating the term…

Loading patent…

Abstract

Thermally decomposable Group IIIa compounds are purified by conveying the relatively impure material through a prescrubber module, then heating the scrubbed Group IIIa compound and conveying same through a preconditioned gas chromatographic column packed with a porous polymeric material. After isolation, the purified material is cooled, demisted amd collected. Thermally decomposable Group Va compounds are purified by conveying the heated relatively impure material through a preconditioned gas chromatographic column packed with a porous polymeric material. After isolation, the purified material is cooled and collected. Epitaxial semiconductor films of purified thermally decomposable Group IIIa and Group Va compounds with added dopant are prepared by diluting the film components with inert carrier gas to predetermined concentration levels, thoroughly mixing the components, then depositing a crystal layer prepared from the mixed components onto a substrate by thermally decomposing the mixed components in a reactor.

Claims7

Dependent claims

A method of purifying thermally decomposable Group IIIa and Group Va compounds of the formula MR.sub.3, wherein M is a Group IIIa or Group Va element and R is selected from one or more of the group consisting of hydrogen, halogen, and aliphatic and aromatic organic moieties having from one or twelve carbon atoms, said method comprising:

passing an impure feed, in the gaseous phase and containing the Group IIIa or Group Va compound and undesirable impurities, through a gas chromatograph having a packing which differentiates the flow through it of said Group IIIa or Group Va compound from said impurities, said feed being injected into said chromatograph as a series of regularly spaced pulses in a continuous stream of an inert carrier gas;
said column differentially separating the Group IIIa or Group Va compound in each respective pulse from the impurities therein so that said Group IIIa or Group Va compound elutes from the column at a different time than said impurities;
and
directing the eluted Group IIIa or Group Va compound component of each respective pulse to a receiver separately from the impurity components of each pulse.

1 more element

Dependencies are inferred from the claim text.