Fabrication of III-V-on-insulator platforms for semiconductor devices
View Patent ↗Embodiments of the present invention provide III-V-on-insulator (IIIVOI) platforms for semiconductor devices and methods for fabricating the same. According to one embodiment, compositionally-graded buffer layers of III-V alloy are grown on a silicon substrate, and a smart cut technique is used to cut and transfer one or more layers of III-V alloy to a silicon wafer having an insulator layer such as an oxide. One or more transferred layers of III-V alloy can be etched away to expose a desired transferred layer of III-V alloy, upon which a semi-insulating buffer layer and channel layer can be grown to yield IIIVOI platform on which semiconductor devices (e.g., planar and/or 3-dimensional FETs) can be fabricated.
1. A III-V-on-insulator (IIIVOI) platform for a semiconductor device, comprising:
a plurality of compositionally-graded III-V buffer layers bonded to a top surface of an insulator layer formed on a semiconductor substrate;
a semi-insulating buffer layer grown on a top surface of the plurality of compositionally-graded III-V buffer layers; and
a channel layer grown on the semi-insulating buffer layer, wherein the channel layer is a single layer directly atop and distinct from the semi-insulating buffer layer.
2. The IIIVOI platform of claim 1 , wherein the insulator layer comprises an oxide.
3. The IIIVOI platform of claim 1 , wherein the plurality of compositionally-graded III-V buffer layers comprise one or more of an indium gallium antimonide (InGaSb) alloy, an indium aluminum antimonide (InAlSb) alloy, and an aluminum gallium nitride (AlGaN) alloy.
4. The IIIVOI platform of claim 1 , wherein the plurality of compositionally-graded III-V buffer layers have bond lengths that increase from a III-V buffer layer immediately adjacent to the substrate to a III-V buffer layer immediately adjacent to the semi-insulating buffer layer.
5. The IIIVOI platform of claim 4 , wherein the plurality of compositionally-graded III-V buffer layers comprise indium gallium arsenide (InGaAs) alloys that increase in concentration of gallium (Ga) and decrease in concentration of indium (In) from the III-V buffer layer immediately adjacent to the substrate to the III-V buffer layer immediately adjacent to the semi-insulating buffer layer.
6. The IIIVOI platform of claim 4 , wherein the plurality of compositionally-graded III-V buffer layers comprise one or more of an indium gallium antimonide (InGaSb) alloy, an indium aluminum antimonide (InAlSb) alloy, and an aluminum gallium nitride (AlGaN) alloy.
7. The IIIVOI platform of claim 4 , wherein the composition of the III-V buffer layer immediately adjacent to the semi-insulating buffer layer has a band energy gap that is less than that of the semi-insulating buffer layer.
8. The IIIVOI platform of claim 7 , wherein the composition of that layer of the compositionally-graded III-V buffer layer on which the semi-insulating buffer layer is grown that is nearest to the substrate is p++ doped or n++ doped, such that such furthest layer is a conductor that enables control of electrical behavior of the channel layer.
9. The IIIVOI platform of claim 8 , further comprising a gate stack built atop the channel layer, wherein the gate stack comprises a double-gated transistor.
10. The IIIVOI platform of claim 1 , further comprising one or more fins are formed in the channel layer.
11. A III-V-on-insulator (IIIVOI) platform for a semiconductor device, comprising:
a III-V buffer layer bonded to an oxide layer disposed on a top surface of semiconductor wafer; and
a channel layer grown on a top surface of the III-V buffer layer.
12. The IIIVOI platform of claim 11 , wherein the III-V buffer layer comprises one or more of an indium gallium antimonide (InGaSb) alloy, an indium aluminum antimonide (InAlSb) alloy, and an aluminum gallium nitride (AlGaN) alloy.
13. A semiconductor structure, comprising:
one or more compositionally-graded III-V buffer layers comprising a first surface and a second surface;
a first substrate bonded to said first surface;
a second substrate bonded to said second surface;
said second substrate comprising a silicon wafer having an oxide layer;
said oxide layer comprising said second surface;
a cleave plane disposed within said one or more compositionally-graded III-V buffer layers; and
said cleave plane comprising implanted ions.