Methods of fabricating integrated circuit devices with components on both sides of a semiconductor layer
View Patent ↗A photonic integrated circuit may include a silicon layer including a waveguide and at least one other photonic component. The photonic integrated circuit may also include a first insulating region arranged above a first side of the silicon layer and encapsulating at least one metallization level, a second insulating region arranged above a second side of the silicon layer and encapsulating at least one gain medium of a laser source optically coupled to the waveguide.
1. A method of making an integrated circuit, the method comprising:
providing a first substrate comprising a carrier substrate, a buried insulating layer, and a semiconductor layer above the buried insulating layer, the buried insulating layer being above the carrier substrate, the first substrate having a first side and an opposite second side, the semiconductor layer having a first semiconductor layer side and a second semiconductor layer side;
from the first semiconductor layer side, forming a first waveguide in the semiconductor layer;
forming a first insulating layer over the first side of the first substrate;
forming a metallization level comprising a metal line within the first insulating layer;
attaching a second substrate over the first insulating layer;
flipping the first substrate after the attaching;
from the second side of the first substrate, removing the carrier substrate and the buried insulating layer after the flipping the first substrate after the attaching;
forming a laser source over the second semiconductor layer side of the semiconductor layer, the laser source being formed directly over the first waveguide; and
encapsulating the laser source in a second insulating layer, wherein the integrated circuit comprising the first waveguide and the laser source forms part of a photonic integrated circuit.
2. The method of claim 1 , wherein forming the laser source comprises:
depositing a n-type semiconductor layer stack over the second semiconductor layer side of the semiconductor layer;
depositing a quantum well layer stack over the n-type semiconductor layer stack;
depositing a p-type semiconductor layer stack over the quantum well layer stack; and
patterning the p-type semiconductor layer stack, the quantum well layer stack, and the n-type semiconductor layer stack.
3. The method of claim 2 , wherein forming the laser source comprises:
forming a first eutectic deposit on the patterned p-type semiconductor layer stack; and
forming a second eutectic deposit on the patterned n-type semiconductor layer stack.
4. The method of claim 3 , further comprising: forming contacts to the first eutectic deposit and the second eutectic deposit, the contacts being formed in the second insulating layer.
5. The method of claim 2 , wherein the n-type semiconductor layer stack comprises n-type InP/InGaAs stack, the quantum well layer stack comprises InGaAsP, and the p-type semiconductor layer stack comprises p-type InP.
6. The method of claim 1 , further comprising:
depositing a third insulating layer before forming the second insulating layer, the third insulating layer contacting the exposed major surface of the semiconductor layer;
depositing an amorphous silicon layer over the third insulating layer; and
patterning the amorphous silicon layer to form a second waveguide directly above the first waveguide.
7. The method of claim 1 , further comprising:
forming a grating coupler in the semiconductor layer, the grating coupler being proximate to the first waveguide.
8. The method of claim 7 , further comprising forming a mirror in the first insulating layer, the mirror being directly formed over the grating coupler.
9. The method according to claim 8 , aligning the grating coupler with the mirror so that light via the semiconductor layer is divided in the grating coupler into a first beam that crosses the second insulating layer toward an optical fiber interface at an exposed surface of the second insulating layer and into a second beam toward the mirror and reflected toward the optical fiber interface.
10. The method according to claim 7 , further comprising forming a modulator in the semiconductor layer, the modulator being proximate the grating coupler.
11. The method of claim 1 , wherein forming the metallization level further comprises forming a heat dissipating radiator in the first insulating layer, wherein the heat dissipating radiator is formed directly over the first waveguide.
12. A method of making an integrated circuit, the method comprising:
providing a first substrate comprising a carrier substrate, a buried insulating layer, and a semiconductor layer, the first substrate having a first side and an opposite second side, the semiconductor layer having a first semiconductor layer side and a second semiconductor layer side;
forming a first waveguide in the semiconductor layer;
forming a metallization level comprising a metal line over the first side of the first substrate;
attaching a second substrate over the metallization level;
flipping the first substrate after the attaching;
from the second side of the first substrate, removing the carrier substrate and the buried insulating layer after the flipping the first substrate after the attaching;
fabricating a laser source over and in contact with the second semiconductor layer side of the semiconductor layer, the laser source being fabricated to be aligned with the first waveguide; and
encapsulating the laser source in a second insulating layer, wherein the integrated circuit comprising the first waveguide and the laser source forms part of a photonic integrated circuit.
13. A method of making an integrated circuit, the method comprising:
providing a first substrate comprising a carrier substrate, a buried insulating layer, and a semiconductor layer, the first substrate having a first side and an opposite second side, the semiconductor layer having a first semiconductor layer side and a second semiconductor layer side;
forming a first waveguide in the semiconductor layer;
forming a metallization level comprising a metal line over the first side of the first substrate;
attaching a second substrate over the metallization level;
flipping the first substrate after the attaching;
from the second side of the first substrate, removing the carrier substrate and the buried insulating layer after the flipping the first substrate after the attaching;
depositing a n-type semiconductor layer stack over and in contact with the second semiconductor layer side of the semiconductor layer;
depositing a quantum well layer stack over the n-type semiconductor layer stack;
depositing a p-type semiconductor layer stack over the quantum well layer stack; and
forming a laser source by patterning the p-type semiconductor layer stack, the quantum well layer stack, and the n-type semiconductor layer stack, the laser source being patterned to be aligned with the first waveguide; and
encapsulating the laser source in a second insulating layer, wherein the integrated circuit comprising the first waveguide and the laser source forms part of a photonic integrated circuit.
14. A method of making an integrated circuit, the method comprising:
providing a first substrate comprising a carrier substrate, a buried insulating layer, and a semiconductor layer, the first substrate having a first side and an opposite second side, the semiconductor layer having a first semiconductor layer side and a second semiconductor layer side;
forming a first waveguide in the semiconductor layer;
forming a metallization level comprising a metal line over the first side of the first substrate;
attaching a second substrate over the metallization level;
flipping the first substrate after the attaching;
from the second side of the first substrate, removing the carrier substrate and the buried insulating layer after the flipping the first substrate after the attaching;
fabricating a laser source over and in contact with the second semiconductor layer side of the semiconductor layer by depositing and patterning a heterostructure comprising a n-type InP/InGaAs layer, a InGaAsP quantum well layer, and a p-type InP layer, the patterning being aligned with the first waveguide; and
encapsulating the laser source in a second insulating layer, wherein the integrated circuit comprising the first waveguide and the laser source forms part of a photonic integrated circuit.
15. The method of claim 14 , wherein fabricating the laser source comprises:
forming a first eutectic deposit on the patterned p-type InP layer; and
forming a second eutectic deposit on the patterned n-type InP/InGaAs layer.
16. The method of claim 15 , further comprising: forming contacts to the first eutectic deposit and the second eutectic deposit, the contacts being formed in the second insulating layer.