Unibody crucible and effusion cell employing such a crucible
AssigneeChorus, LLC
InventorsPaul E. Colombo, Robert F. Donadio
Life of this patent
Estimating the term…
Abstract
A unibody, monolithic, one-piece negative draft crucible for a MBE effusion cell. The crucible maximizes capacity, uniformity and long term flux stability, and minimizes oval defects, depletion effects, and short term shutter-related flux transients. The invention also provides a method and mandrel apparatus for making a unibody containment structure, such as a crucible formed of PBN, having a negative draft, via chemical vapor deposition.
Claims16
An effusion cell for creating a molecular beam of material to be deposited epitaxially on a substrate, comprising:
- a support assembly comprising a mounting flange and at least one support post extending from the mounting flange;
- and
- a head assembly connected to the at least one support post, the head assembly comprising a container for holding the material and a heater surrounding at least a portion of the container for heating the material in the container, the container comprising a rigid wall structure enclosing an interior space, said wall structure being made of pyrolytic boron nitride and having a substantially uniform wall thickness, said wall structure defining a base portion and a neck portion attached to the base portion, the neck portion having a negative draft angle extending away from the base portion and terminating in a neck orifice, the base portion having a first peripheral dimension and the neck orifice having a second peripheral dimension, said second peripheral dimension being less than said first peripheral dimension.
An effusion cell for creating a molecular beam of material to be deposited epitaxially on a substrate, comprising:
- a support assembly comprising a mounting flange and at least one support post extending from the mounting flange;
- and
- a head assembly connected to the at least one support post, the head assembly comprising a container for holding the material and a heater surrounding at least a portion of the container for heating the material in the container, the container comprising a rigid wall structure enclosing an interior space, said wall structure defining a base portion and a neck portion attached to the base portion, the neck portion having a negative draft angle extending away from the base portion and terminating in a neck orifice, the base portion having a first peripheral dimension and the neck orifice having a second peripheral dimension, said second peripheral dimension being less than said first peripheral dimension;
- wherein activation of the heater causes the material in the container to evaporate to form a molecular beam, effuse out of said neck orifice, and be deposited epitaxially on the substrate.
Dependencies are inferred from the claim text.