Plasma diced wafers and methods thereof

A method of forming devices comprising:

• providing a processed wafer processed with a plurality of devices arranged in rows and columns separated by first and second saw streets in first and second orthogonal directions, wherein the processed wafer includes
• a wafer having opposing inactive and active wafer surfaces,
• a BEOL dielectric having opposing top and bottom BEOL dielectric surfaces, wherein the bottom surface is disposed on the active wafer surface,
• a passivation layer having opposing top and bottom passivation surfaces, wherein the bottom passivation surface is disposed on the top BEOL dielectric surface;
• laser cutting the passivation layer to form passivation openings to expose the top BEOL dielectric surface in kerf regions within the first and second saw streets;
• performing a first plasma etch to etch a first portion of the processed wafer in the kerf regions of the processed wafer from the top BEOL surface to an upper portion of the wafer, wherein the first plasma etch produces scalloped sidewalls in the kerf regions;
• and
• performing a second plasma etch to etch a second portion of the processed wafer in the kerf regions, the second portion comprises a remaining portion of the wafer from a bottom of the upper portion of the wafer to the inactive wafer surface to singulate the processed wafer into individual devices, wherein the second plasma etch produces vertical sidewalls in the second portion.

A device comprising:

• a device substrate;
• a BEOL dielectric disposed on an active substrate surface of the substrate;
• a passivation layer disposed on a top passivation surface of the passivation layer, wherein the passivation layer serves as a plasma dicing mask for plasma dicing a wafer with a plurality of devices;
• device sidewalls defined by side substrate surfaces of the substrate, side BEOL surfaces of the BEOL dielectric and side passivation surfaces of the passivation layer, wherein the device sidewalls comprise
• a first device sidewall portion from the top BEOL surface to an upper portion of the device substrate, the first device sidewall portion comprises a scalloped device sidewall portion with first plasma etched sidewalls, and
• a second device sidewall portion from a bottom of the upper portion of the device substrate to the bottom substrate surface, the second device sidewall portion comprises a vertical device sidewall portion with second plasma etched sidewalls.