Designs of thermal insulation for micro-ring resonator (MRR) in on-cavity pic (OCPIC) to achieve effective thermal tuning
Embodiments disclosed herein include optoelectronic systems and methods of forming such systems. In an embodiment, an optoelectronic system comprises a first substrate, a second substrate over the first substrate, and a micro-ring resonator (MRR) over the second substrate. In an embodiment, a heater is integrated into the MRR, a cladding is over the MRR, and an opening is through the first substrate and the second substrate to expose a bottom surface of the MRR.
1 . An optoelectronic system, comprising:
a first substrate;
a second substrate over the first substrate;
a micro-ring resonator (MRR) over the second substrate, wherein the MRR comprises an N-doped layer, a P-doped layer over the N-doped layer, and an N-doped region in the P-doped layer;
a heater integrated into the MRR;
wherein the heater is between the N-doped region and the P-doped region;
a cladding over the MRR; and
an opening through the first substrate and the second substrate to expose a bottom surface of the MRR.
2 . The optoelectronic system of claim 1 , wherein the first substrate comprises silicon and the second substrate comprises an oxide.
3 . The optoelectronic system of claim 1 , wherein the opening continues into the cladding adjacent to sidewalls of the MRR.
4 . The optoelectronic system of claim 3 , wherein the opening continues into the cladding past a top surface of the MRR.
5 . The optoelectronic system of claim 1 , wherein the opening through the first substrate has substantially vertical sidewalls.
6 . The optoelectronic system of claim 1 , wherein the opening through the first substrate has tapered sidewalls.
7 . The optoelectronic system of claim 1 , further comprising:
contacts coupled to a top surface of the MRR.
8 . The optoelectronic system of claim 7 , wherein the contacts are electrically coupled to pads on a top surface of the cladding.
9 . The optoelectronic system of claim 1 , wherein the MRR has a thickness that is approximately 250 nm or less.
10 . A method of forming an optoelectronic system, comprising:
forming a micro-ring resonator (MRR) with a heater on a substrate, wherein the substrate is a silicon on insulator (SOI) substrate with a silicon substrate and an oxide layer over the silicon substrate, wherein a cladding is provided over and around the MRR, wherein the MRR comprises an N-doped layer, a P-doped layer over the N-doped layer, and an N-doped region in the P-doped layer, and wherein the heater is between the N-doped region and the P-doped region;
applying a mask to a bottom surface of the silicon substrate, wherein an opening of the mask is aligned with the MRR; and
etching through the silicon substrate and the oxide layer to expose a bottom surface of the MRR.
11 . The method of claim 10 , wherein a width of the opening of the mask is wider than a width of the MRR.
12 . The method of claim 11 , wherein the etching further comprises etching the cladding adjacent to the MRR.
13 . The method of claim 12 , wherein the etching of the cladding extends past a top surface of the MRR.
14 . The method of claim 10 , wherein the etching is a dry etching process.
15 . The method of claim 10 , wherein the etching is a wet etching process.
16 . An optoelectronic system, comprising:
a package substrate;
a photonics integrated circuit (PIC) coupled to the package substrate, wherein the PIC comprises:
a first substrate;
a second substrate over the first substrate;
a micro-ring resonator (MRR) over the second substrate, wherein the MRR comprises an N-doped layer, a P-doped layer over the N-doped layer, and an N-doped region in the P-doped layer;
a heater integrated into the MRR;
wherein the heater is between the N-doped region and the P-doped region;
a cladding over the MRR; and
an opening through the first substrate and the second substrate to expose a bottom surface of the MRR; and
an electronic integrated circuit (EIC) coupled to the PIC.
17 . The optoelectronic system of claim 16 , wherein the opening has vertical sidewalls through the first substrate and the second substrate.
18 . The optoelectronic system of claim 16 , wherein the opening extends into the cladding adjacent to the MRR.