Laser chips attached to a photonics chip by multiple anchors
Structures including a photonics chip and a cavity-mounted laser chip, and methods of forming such structures. The structure comprises a photonics chip including a substrate and a cavity in the substrate, a laser chip including a body inside the cavity, a first anchor disposed inside the cavity adjacent to a first corner of the body of the laser chip, and a second anchor disposed inside the cavity adjacent to a second corner of the body of the laser chip. The first and second anchors are configured to attach the laser chip to the photonics chip.
1 . A structure comprising:
a photonics chip including a substrate and a cavity in the substrate, the cavity including a bottom inside the substrate and a sidewall, and the substrate including a first ledge that projects away from the bottom of the cavity;
a redistribution layer with a first portion on the bottom of the cavity adjacent to the first ledge and a second portion on the sidewall of the cavity, the redistribution layer comprising a metal;
a plurality of mechanical stops that project away from the first ledge;
a laser chip including a body inside the cavity, the body having a first corner and a second corner;
a first anchor disposed inside the cavity adjacent to the first corner of the body of the laser chip; and
a second anchor disposed inside the cavity adjacent to the second corner of the body of the laser chip,
wherein the first anchor and the second anchor are configured to attach the laser chip to the photonics chip, and the first ledge is arranged between the first anchor in the first corner and the second anchor in the second corner.
2 . The structure of claim 1 wherein the photonics chip includes an edge coupler adjacent to the sidewall of the cavity.
3 . The structure of claim 2 wherein the laser chip includes a light output, and the laser chip is configured to emit light from the light output toward the edge coupler.
4 . The structure of claim 1 wherein the first anchor comprises a first solder bump, and the second anchor comprises a second solder bump.
5 . The structure of claim 4 wherein the first anchor further includes a first bond pad on the photonics chip and a first bond pad on the laser chip that is attached by the first solder bump to the first bond pad on the photonics chip, and the second anchor further includes a second bond pad on the photonics chip and a second bond pad on the laser chip that is attached by the second solder bump to the second bond pad on the photonics chip.
6 . The structure of claim 1 wherein the first anchor comprises a first adhesive bump, and the second anchor comprises a second adhesive bump.
7 . The structure of claim 6 wherein the first anchor further includes a first bond pad on the photonics chip and a first bond pad on the laser chip that is attached by the first adhesive bump to the first bond pad on the photonics chip, and the second anchor further includes a second bond pad on the photonics chip and a second bond pad on the laser chip that is attached by the second adhesive bump to the second bond pad on the photonics chip.
8 . The structure of claim 1 wherein the substrate includes a column in the first corner that extends away from the bottom of the cavity, and the first anchor is disposed between the column and the body of the laser chip.
9 . The structure of claim 8 wherein the laser chip includes a recess, the first anchor includes a bond pad on the laser chip, and the bond pad is arranged inside the recess.
10 . The structure of claim 9 wherein the first anchor includes a solder bump and a bond pad on the column of the substrate, and the solder bump is disposed between the bond pad on the laser chip and the bond pad on the column of the substrate.
11 . The structure of claim 1 wherein the first ledge includes a first end adjacent to the first anchor in the first corner and a second end adjacent to the second anchor in the second corner, and the body of the laser chip includes a portion between the first corner and the second corner that contacts the mechanical stops.
12 . The structure of claim 11 wherein the photonics chip includes an edge coupler adjacent to the sidewall, and the first anchor in the first corner is disposed between the sidewall and the first end of the first ledge.
13 . The structure of claim 12 further comprising:
a third anchor disposed inside the cavity between the first anchor and the second anchor,
wherein the third anchor is configured to attach the laser chip to the photonics chip, the substrate includes a second ledge that projects away from the bottom of the cavity, and the third anchor is disposed along the sidewall between the first ledge and the second ledge.
14 . The structure of claim 11 further comprising:
a solder bump on the portion of the redistribution layer, the solder bump arranged between the first end of the first ledge and the second end of the first ledge.
15 . The structure of claim 1 wherein the body of the laser chip includes a notch, and the first ledge includes a portion disposed inside the notch in the body of the laser chip.
16 . The structure of claim 1 wherein the cavity in the substrate includes a first corner and a second corner, the first corner of the cavity is adjacent to the first anchor in the first corner of the laser chip, and the second corner is adjacent to the second anchor in the second corner of the laser chip.
17 . The structure of claim 1 wherein the first anchor includes a first solder bump having a first height, and further comprising:
a second solder bump on the first portion of the redistribution layer, the second solder bump having a second height that is less than the first height.
18 . The structure of claim 17 wherein the laser chip includes a recess, the first anchor includes a bond pad on the laser chip, and the bond pad and a portion of the first solder bump are arranged inside the recess.
19 . The structure of claim 1 wherein the photonics chip includes an interconnect structure on the substrate, the interconnect structure has a surface adjacent to the cavity, and the second portion of the redistribution layer extends onto the surface of the interconnect structure.
20 . A method comprising:
forming a cavity in a substrate of a photonics chip, wherein the cavity includes a bottom inside the substrate and a sidewall, and the substrate includes a ledge that projects away from the bottom of the cavity;
forming a redistribution layer with a first portion on the bottom of the cavity adjacent to the ledge and a second portion on the sidewall of the cavity, wherein the redistribution layer comprises a metal;
forming a plurality of mechanical stops that project away from the ledge; and
forming a first anchor and a second anchor that are disposed inside the cavity,
wherein a laser chip includes a body disposed inside the cavity, the first anchor is disposed adjacent to a first corner of the body of the laser chip, the second anchor is disposed adjacent to a second corner of the body of the laser chip, and the first anchor and the second anchor are configured to attach the laser chip to the photonics chip.