Inkjet printhead with deep reverse etch in integrated circuit wafer

An ink jet printhead comprising:

• a plurality of nozzles;
• a bubble forming chamber corresponding to each of the nozzles respectively, the bubble forming chambers adapted to contain a bubble forming liquid;
• and,
• at least one heater element disposed in each of the bubble forming chambers respectively, for thermal contact with the bubble forming liquid to form a gas bubble that causes the ejection of a droplet of bubble forming liquid from the nozzle;
• the nozzles, the bubble forming chambers and the heater elements being formed on an ejection side of a silicon wafer substrate using lithographically masked etching and deposition techniques, and conduits are etched into the reverse side of the silicon wafer opposite the ejection side, the conduits being configured for feeding bubble forming liquid to the bubble forming chambers, wherein,
• the conduits are etched to a depth greater than 150 microns from the reverse side of the wafer.