Browse Prior Art Database

Maintenance of Deposition Rate in the Preparation of Molybdenum by MoCl(5) Reduction

IP.com Disclosure Number: IPCOM000091515D
Original Publication Date: 1968-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Kaplan, L: AUTHOR

Abstract

This technique maintains a constant degree of saturation in the vaporizer of a chemical vapor deposition system. A carrier gas, e.g., hydrogen, is passed into a vaporizer which contains the source material, e.g. MoCl(5), in the form of large pellets. The vaporizer is maintained at a sufficiently high temperature so that the source material is vaporized and carried by the carrier gas into a reaction chamber. Constancy of saturation of the source material in the carrier gas is dependent upon maintaining the total surface area of the source material that is exposed to the carrier gas substantially constant.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 85% of the total text.

Page 1 of 1

Maintenance of Deposition Rate in the Preparation of Molybdenum by MoCl(5) Reduction

This technique maintains a constant degree of saturation in the vaporizer of a chemical vapor deposition system. A carrier gas, e.g., hydrogen, is passed into a vaporizer which contains the source material, e.g. MoCl(5), in the form of large pellets. The vaporizer is maintained at a sufficiently high temperature so that the source material is vaporized and carried by the carrier gas into a reaction chamber. Constancy of saturation of the source material in the carrier gas is dependent upon maintaining the total surface area of the source material that is exposed to the carrier gas substantially constant.

In previous techniques, fine powders of the source material are employed in the vaporizer to maximize the surface area exposed to the carrier gas. However, since the source material is maintained at the vaporization temperature, particles of the source material sinter and tend to form large crystals. This causes preferred channels through the sintered source material between input and output ports which reduces the exposed surface area and, hence, the rate of vaporization.

The use of large pellets of the source material in the vaporizer substantially reduces the possibility of forming channels. Thus saturation of the source material in the carrier gas can be maintained if a sufficiently large number of pellets are placed in the vaporizer. Alternatively, to avoid channels in the e...