Monolithic single chip integrated radio frequency front end module configured with single crystal acoustic filter devices
A method of manufacture and structure for a monolithic single chip single crystal device. The method can include forming a first single crystal epitaxial layer overlying the substrate and forming one or more second single crystal epitaxial layers overlying the first single crystal epitaxial layer. The first single crystal epitaxial layer and the one or more second single crystal epitaxial layers can be processed to form one or more active or passive device components. Through this process, the resulting device includes a monolithic epitaxial stack integrating multiple circuit functions.
1. A monolithic single chip single crystal device, the device comprising:
a substrate having a substrate surface region and an underlying cavity region;
a first single crystal epitaxial layer formed overlying the substrate surface region;
a passive device configured within the first single crystal epitaxial layer and within the underlying cavity region;
one or more second single crystal epitaxial layers formed overlying the first single crystal epitaxial layer;
an active device configured overlying the one or more second single crystal epitaxial layers; and
wherein the first single crystal epitaxial layer and the one or more second single crystal epitaxial layers are formed as a monolithic epitaxial stack integrating multiple circuit functions.
2. The device of claim 1 wherein the substrate is selected from one of the following: a silicon substrate, a sapphire substrate, silicon carbide substrate, a GaN bulk substrate, a GaN template, an AlN bulk, an AlN template, and an Al x Ga 1-x N template.
3. The device of claim 1 wherein the first single crystal epitaxial layer comprises an aluminum nitride (AlN) material, and wherein the first single crystal epitaxial layer is characterized by a thickness of about 0.01 um to about 10.0 um.
4. The device of claim 1 wherein at least one of the one or more second single crystal epitaxial layers comprises a single crystal aluminum gallium nitride (Al x Ga 1-x N) material, and wherein the second single crystal epitaxial layer is characterized by a composition of 0≤X<1.0 and a thickness of about 200 nm to about 1200 nm.
5. The device of claim 1 wherein at least one of the one or more second single crystal epitaxial layers comprises single crystal aluminum gallium nitride (Al x Ga 1-x N) materials, and wherein the second single crystal epitaxial layer is characterized by a composition of 0.10≤X<1.0 and a thickness of about 10 nm to about 40 nm.
6. The device of claim 1 wherein the one or more active or passive components comprises one or more switches, filters, or amplifiers.
7. The device of claim 1 further comprising a cap layer overlying the one or more second epitaxial layers, wherein the cap layer comprises gallium nitride (GaN) materials.
8. The device of claim 7 wherein the cap layer is characterized by a thickness of about 0.10 nm to about 5.0 nm.
9. The device of claim 7 wherein the active device is configured overlying the cap layer.