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Article comprising an oxide layer on a GaAs or GaN-based semiconductor body

Imported: 23 Feb '17 | Published: 22 Oct '02

Minghwei Hong, Ahmet Refik Kortan, Jueinai Raynien Kwo, Joseph Petrus Mannaerts

USPTO - Utility Patents

Abstract

We have found that a single crystal, single domain oxide layer of thickness less than 5 nm can be grown on a (100) oriented GaAs-based semiconductor substrate. Similar epitaxial oxide can be grown on GaN and GaN-based semiconductors. The oxide typically is a rare earth oxide of the Mn

2 0 3 structure (e.g., Gd

2O

3). The oxide/semiconductor interface can be of high quality, with low interface state density, and the oxide layer can have low leakage current and high breakdown voltage. The low thickness and high dielectric constant of the oxide layer result in a MOS structure of high capacitance per unit area. Such a structure advantageously forms a GaAs-based MOS-FET.

Description

BRIEF DESCRIPTION OF THE DRAWING'S

FIG. 1 schematically depicts an exemplary device, namely, a MOS-FET;

FIG. 2 shows the diagram of an exemplary circuit comprising complementary MOS-FETs;

FIGS. 3-5 show electrical characteristics of an exemplary enhancement-mode p-channel GaAs MOS-FET;

FIGS. 6-8 show measurement data from GaAs/oxide/metal structures of various oxide compositions;

FIGS. 9-11 show in-situ RHEED patterns of, respectively, a (100) GaAs surface along [011] and [011] axes, a 1.5 nm thick (110) Gd

2O

3 film along [001], [110] and [111] axes; and a 18.5 nm thick (110) Gd

2O

3 film along the same three axes;

FIGS. 12-13 show, respectively, x-ray −2 scans of the (440) Bragg reflection of the (110) oriented Gd

2O

3 films of 18.5 nm, 3.5 nm and 1.5 nm, and rocking curve scans of these peaks about the angle for the three samples;

FIG. 14 shows the leakage current density versus applied field for Gd

2O

3 films with thicknesses of 26.0, 18.5, 14.0, 3.5 and 1.5 nm thickness, respectively.

Like or analogous features generally are designated by the same numeral in different figures. The figures are not to scale.

Claims

1. Article comprising a planar semiconductor substrate having a major surface of (001) orientation, and an oxide layer disposed on the major substrate and forming an interface therewith, with the interface having an interface state density of 10

11 cm

−2eV

−1 or less, and the oxide layer being epitaxial with the major surface;

CHARACTERIZED IN THAT

2. Article according to claim 1, wherein the oxide layer is selected from the group consisting of the oxides of Y, Sc, La, Nd, Gd, Dy, Ho, Er and Lu.

3. Article according to claim 1, wherein the oxide is Gd

2O

3.

4. Article according to claim 1, wherein the article comprises a field effect transistor, with the oxide layer being a gate oxide, of the field effect transistor.

5. Article according to claim 1, further comprising an epitaxial single crystal semiconductor layer disposed on the oxide layer.