Epitaxial oxide device with impact ionization
The present disclosure describes epitaxial oxide devices with impact ionization. In some embodiments, a semiconductor device comprises: a first semiconductor layer; a second semiconductor layer coupled to the first semiconductor layer; and a first and a second electrical contact coupled to the second and first semiconductor layers, respectively. The first semiconductor layer can comprise a first epitaxial oxide material with a first bandgap and an impact ionization region. The second semiconductor layer can comprise a second epitaxial oxide material with a second bandgap that is wider than the first bandgap.
1. A semiconductor device, comprising:
a first semiconductor layer comprising:
a first epitaxial oxide material that is not intentionally doped (NID), the first epitaxial oxide material comprising a first bandgap; and
an impact ionization region;
a second semiconductor layer coupled to a first side of the first semiconductor layer, the second semiconductor layer comprising a second epitaxial oxide material, the second epitaxial oxide material comprising a second bandgap that is wider than the first bandgap;
a third semiconductor layer coupled to a second side of the first semiconductor layer, the third semiconductor layer comprising a third epitaxial oxide material that is n-type, the third epitaxial oxide material comprising a third bandgap that is wider than the first bandgap;
a first electrical contact coupled to the second semiconductor layer; and
a second electrical contact coupled to the third semiconductor layer;
wherein the third semiconductor layer is located between the first semiconductor layer and the second electrical contact.
2. The semiconductor device of claim 1 , wherein the semiconductor device is configured to:
inject a hot electron from the first electrical contact, through the second semiconductor layer, and into the first semiconductor layer; and
form, from the hot electron, an excess electron-hole pair in the impact ionization region via impact ionization.
3. The semiconductor device of claim 1 , wherein the semiconductor device is configured to:
inject a hot electron from the first electrical contact, through the second semiconductor layer, and into the first semiconductor layer; and
form, from the hot electron, two electrons in the impact ionization region via impact ionization.
4. The semiconductor device of claim 1 , wherein the first bandgap is equal to or greater than 5 eV.
5. The semiconductor device of claim 1 , wherein the second epitaxial oxide material is p-type.
6. The semiconductor device of claim 1 , wherein the first and/or second electrical contact comprises a high work function metal.
7. The semiconductor device of claim 1 , wherein the first and/or second electrical contact comprises Ni, Os, Se, Pt, Pd, Ir, Au, W or alloys thereof.
8. The semiconductor device of claim 1 , wherein the first and/or second electrical contact comprises C, Co, Be, Rh, Te, Ge, Fe or Si.
9. The semiconductor device of claim 1 , wherein the first and/or second electrical contact comprises a low work function metal.
10. The semiconductor device of claim 1 , wherein the first and/or second electrical contact comprises Ba, Na, Cs, Nd or alloys thereof.
11. The semiconductor device of claim 1 , wherein the first and/or second electrical contact comprises Rb, K, Eu, Sr, Pr, Yb, Sm, Dy, Ca, Pm, Ce, or Li.
12. The semiconductor device of claim 1 , wherein the first semiconductor layer comprises a breakdown voltage per unit thickness from 1 MV/cm to 10 MV/cm.
13. The semiconductor device of claim 1 , wherein the semiconductor device comprises a breakdown voltage from 100 V to 10,000 V at specific ON resistances from 10 −4 to 1 mΩ-cm 2 .
14. The semiconductor device of claim 1 , wherein the semiconductor device is configured to withstand a bias greater than 100 V applied across the first and the second electrical contacts without breaking down.
15. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises (Al x Ga 1−x ) 2 O 3 , with 0≤x≤1.
16. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises Ga 2 O 3 with an orthorhombic, hexagonal, monoclinic, cubic, tetragonal, rhombic or trigonal crystal symmetry.
17. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises Ga 2 O 3 , and the second epitaxial oxide material comprises Al 2 O 3 .
18. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises a material listed in the tables in FIGS. 76 A- 1 and 76 A- 2 , and the second epitaxial oxide material comprises a material listed in the tables in FIGS. 76 A- 1 and 76 A- 2 .
19. The semiconductor device of claim 18 , wherein the first bandgap is equal to or greater than 5 eV.
20. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises Li.
21. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises Ni.
22. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises:
Mg;
Ga or Al; and
O.
23. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises Ge.
24. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises a rare earth element.
25. The semiconductor device of claim 1 , wherein the first epitaxial oxide material comprises a gradient in composition.
26. The semiconductor device of claim 1 , wherein the second semiconductor layer comprises a tunnel barrier between the first electrical contact and the first semiconductor layer.
27. The semiconductor device of claim 1 , wherein the semiconductor device is a light emission device, and wherein the impact ionization region comprises an optical gain medium.
28. The semiconductor device of claim 1 , wherein the semiconductor device is an avalanche photodiode.