Browse Prior Art Database

Isochemical, Isostructural Materials for Electronic Device Applications

IP.com Disclosure Number: IPCOM000035742D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Holtzberg, F: AUTHOR [+3]

Abstract

Single crystal electronic devices can be formed using lattice matched layers with the possibility of tailoring electrical properties over wider ranges than are presently available, using rare earth chalcogenides.

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Isochemical, Isostructural Materials for Electronic Device Applications

Single crystal electronic devices can be formed using lattice matched layers with the possibility of tailoring electrical properties over wider ranges than are presently available, using rare earth chalcogenides.

Many thin film device structures are formed from structurally similar layers that have different electrical properties. Lattice mismatch between the layers causes electron scattering at interfaces that degrades a device's operating characteristics. The requirement to match the lattices of different material systems introduces a severe materials constraint for superlattices and for compound or alloy semiconductor devices.

There exists a group of materials that exhibit a wide range of electrical properties which are determined by controllable changes in composition that alter only the proportions of the chemical constituents. The crystal structure and lattice constants are unaffected by these compositional changes. This permits the epitaxial growth of layers with different electrical properties. In contrast to III- V and II-VI compound semiconductors, the valences of these elements are not necessarily symmetric about Group IV.

A group of materials which exhibits these properties includes the sulfides and selenides of the rare earths. These materials have the thorium phosphide structure, and form compounds with compositions of the form RE3-xvxSe4, where RE represents the rare earth and v a vacancy (S can be substituted for Se). With x=O, the material is a metal (RE3Se4), while with x=1/3 the material is insulating (stoichiometric RE2Se3)....