Oxide heterostructures having spatially separated electron-hole bilayers

Patent metadata

Field	Value
Publication number	US-2018337238-A1
Application number	US-201715596505-A
Country	US
Kind code	A1
Filing date	May 16, 2017
Priority date	May 16, 2017
Publication date	Nov 22, 2018
Grant date	—

Abstract

Oxide heterostructures that form spatially separated electron-hole bilayers are provided. Also provided are electronic devices that incorporate the oxide heterostructures. The oxide heterostructure includes a base layer of SrTiO3, a polar layer of LaAlO2, and a non-polar layer of SrTiO3. Within the oxide heterostructures, a two-dimensional hole gas (2DHG) is formed at the interface between the non-polar layer and the polar layer and a two-dimensional electron gas (2DEG) is formed at the interface between the polar layer and the base layer.

First claim

1 . An oxide heterostructure comprising:
a base layer comprising SrTiO 3 ; a polar layer comprising LaAlO 3 on the base layer; a non-polar layer comprising SrTiO 3 on the polar layer, the SrTiO 3 of the non-polar layer having a lower oxygen vacancy concentration than the SrTiO 3 of the base layer, a two-dimensional electron gas confined at an interface between the base layer and the polar layer; and a two-dimensional hole gas confined at an interface between the polar layer and the non-polar layer.

2 . (canceled)

3 . The heterostructure of claim 1 , wherein the SrTiO 3 of the non-polar layer has an oxygen vacancy index of no greater than 2 a.u.

4 . The heterostructure of claim 1 , wherein the two-dimensional hole gas has a Hall hole mobility of at least 4×10 2 cm 2 V −1 s −1 at a temperature of 20 K.

5 . The heterostructure of claim 1 , wherein the two-dimensional hole gas has a Hall hole mobility that is at least as high as the Hall electron mobility of the two-dimensional electron gas at a temperature in the range from 1 K to 50 K.

6 . (canceled)

7 . (canceled)

8 . The heterostructure of claim 1 , wherein the polar layer has a thickness of at least 5 unit cells.

9 . The heterostructure of claim 3 , wherein the polar layer has a thickness of at least 5 unit cells.

10 . (canceled)

11 . A transistor comprising:
the oxide heterostructure of claim 1 ; a source electrode; a drain electrode, wherein the source electrode and the drain electrode are in electrical communication through either the 2DEG or the 2DHG; and a gate electrode that is configured to alter the current flowing between the source electrode and the gate electrode when a gate voltage is applied to the gate electrode.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Eom Chang-Beom
• Lee Hyungwoo

Classifications

• H01L29/778

  Electricity · mapped topic

• H01L29/24 Primary

  Electricity · mapped topic

• H10D62/8271

  comprising only oxide semiconductor materials heterojunctions, e.g. IGZO/IZO · CPC title

• H10D30/472 Primary

  having lower bandgap active layer formed on top of wider bandgap layer, e.g. inverted HEMT · CPC title

• H10D99/00

  Subject matter not provided for in other groups of this subclass · CPC title