Method for fabricating a thermal bubble inkjet print head with rapid ink refill mechanism and off-shooter heater

A method for fabricating a thermal bubble inkjet head equipped with heaters and a rapid ink refill mechanism comprising the steps of:

• providing a silicon substrate having a top surface and a bottom surface;
• forming a first insulating material layer of at least 1000 Å thick on said top surface;
• forming a second insulating material layer of at least 1000 Å thick on said bottom surface;
• reactive ion etching an opening for a manifold in said second insulating material layer on said bottom surface;
• wet etching a funnel-shaped manifold in said silicon substrate;
• forming two spaced-apart heaters on said first insulating material layer on said top surface;
• depositing and patterning two interconnects with a conductive metal each in electrical communication with one of said two spaced-apart heaters;
• depositing a third insulating material layer on top of said two spaced-apart heaters and said first insulating material layer;
• spin-coating a first photoresist layer of at least 2000 Å thick on top of said third insulating material layer;
• patterning by UV exposure a primary and an auxiliary ink chamber in fluid communication with each other in said first photoresist layer;
• depositing a metal seed layer on said first photoresist layer and patterning an inkjet orifice in said metal seed layer;
• spin-coating a second photoresist layer of at least 2000 Å thick on said metal seed layer and patterning said inkjet orifice;
• removing said developed second photoresist layer except on top of said inkjet orifice;
• electroplating Ni on top of said metal seed layer encapsulating said second photoresist layer on top of said inkjet orifice;
• stripping away said second photoresist layer on top of said inkjet orifice;
• reactive ion etching away said second insulating material layer on said bottom surface of the silicon substrate and said first insulating material layer exposed in said manifold;
• and stripping away said first photoresist layer from said primary and auxiliary ink chambers.