Systems and Methods for a Semicdonductor Structure Having Multiple Semiconductor-Device Layers

A device comprising:

• a first semiconductor device layer including a first semiconductor device for performing a first circuit function;
• an oxide layer disposed directly on the first semiconductor device layer;
• and
• a second semiconductor device layer including a channel material layer and a second semiconductor device for performing a second circuit function, wherein the second circuit function is different from the first circuit function, the second semiconductor device layer disposed directly on the oxide layer such that the oxide layer electrically insulates the channel material layer from the first semiconductor device, wherein the second semiconductor device layer includes a gate disposed on the channel material and a gate spacer disposed along a sidewall of the gate such that the gate spacer extends to the oxide layer.

A method comprising:

• fabricating a first semiconductor device layer on a first substrate, the first semiconductor device layer including a first semiconductor device for performing a first circuit function;
• bonding the first semiconductor device layer to an oxide layer of a second substrate, the second substrate including a channel material layer disposed above the oxide layer;
• and
• after bonding the first semiconductor device layer to the oxide layer of the second substrate, fabricating a second semiconductor device layer on the channel material layer by patterning the channel material layer to form a fin active region on the oxide layer and forming a fin field effect transistor on the fin active region, the second semiconductor device layer including a second semiconductor device performing a second circuit function that is different from the first circuit function.