Crack propagation stops for dicing of planar lightwave circuit devices
View Patent ↗One aspect of the present invention relates to a method of dicing a substrate containing a plurality of non-rectangular shaped optical integrated circuits, involving forming stop cracks in the wafer, each stop crack adjacent and substantially parallel one of the non-rectangular shaped optical integrated circuits, and cutting the substrate in a curvilinear manner substantially parallel to a stop crack. Another aspect of the present invention relates to an optical structure containing a substrate; a plurality of non-rectangular shaped optical integrated circuits on the substrate, each non-rectangular shaped optical integrated circuit having an active region; and at least one stop crack positioned adjacent each non-rectangular shaped optical integrated circuit.
1. A method of increasing optical integrated circuit yield per wafer, comprising:
providing a wafer comprising a plurality of non-rectangular shaped optical integrated circuits;
forming stop cracks in the wafer, each stop crack adjacent one of the non-rectangular shaped optical integrated circuits;
cutting the wafer in a curvilinear manner to yield a plurality of separated non-rectangular shaped optical integrated circuits.
2. The method according to claim 1 , wherein the stop cracks are curvilinear and positioned substantially parallel to the non-rectangular shaped optical integrated circuits.
3. The method according to claim 1 , wherein the stop cracks have a width of about 25 microns or more and about 0.25 mm or less.
4. The method according to claim 1 , wherein the stop cracks have a depth of at least about 10% of the thickness of the wafer.
5. The method according to claim 1 , wherein the stop cracks are formed using one selected from the group consisting of a saw, a milling machine, a laser, a water jet, and chemical etching.
6. The method according to claim 1 , wherein the optical integrated circuit is a planar lightwave circuit.
7. The method according to claim 1 , wherein cutting is conducted by one selected from the group consisting of laser cutting and water jet cutting.
8. A method of dicing a substrate comprising a plurality of non-rectangular shaped optical integrated circuits, comprising:
forming stop cracks in the wafer, each stop crack adjacent and substantially parallel one of the non-rectangular shaped optical integrated circuits; and
cutting the substrate in a curvilinear manner substantially parallel to a stop crack.
9. The method according to claim 8 , wherein each non-rectangular shaped optical integrated circuit has two stop cracks adjacent and substantially parallel therewith.
10. The method according to claim 8 , wherein the stop cracks are formed using one selected from the group consisting of a saw, a milling machine, a laser, a water jet, and chemical etching.
11. The method according to claim 8 , wherein the stop crack has a width of about 10 microns or more and about 0.5 mm or less.
12. The method according to claim 8 , further comprising filling the stop crack with a dielectric material prior to cutting the substrate.
13. The method according to claim 8 , wherein the cutting is conducted by one selected from the group consisting of laser cutting and water jet cutting.
14. An optical integrated circuit, comprising:
a substrate comprising two curvilinear longitudinal edges;
a non-rectangular shaped active region comprising optical components; and
at least one stop crack positioned substantially parallel and proximate one of the curvilinear longitudinal edges.
15. An optical integrated circuit according to claim 14 , comprising two stop cracks, each stop crack positioned substantially parallel and proximate one of the curvilinear longitudinal edges.