US 7,320,937 B1
Method of reliably electroless-plating integrated circuit die
Rathindra N. Pal, Beltsville, Md. (US); and Kingsley R. Berlin, Odenton, Md. (US)
Assigned to The United States of America as represented by the National Security Agency, Washington, D.C. (US)
Filed on Oct. 19, 2005, as Appl. No. 11/253,879.
Int. Cl. H01L 21/44 (2006.01)
U.S. Cl. 438—678  [438/677; 257/E21.174; 257/E21.224] 13 Claims
OG exemplary drawing
 
1. Method of electroless-plating at least one integrated circuit die, comprising the steps of:
(a) receiving the at least one integrated circuit die, where each at least one integrated circuit die has a pad side and a backside;
(b) attaching the at least one integrated circuit die backside to a holder, where the holder has a dielectric adhesive layer applied thereto;
(c) cleaning the at least one integrated circuit die with more than one cleaning solution;
(d) rinsing each at least one integrated circuit die in de-ionized water after each cleaning in the more than one cleaning solution;
(e) immersing the at least one integrated circuit die into a first metal oxide etchant for a user-definable time;
(f) cleaning the at least one integrated circuit die in de-ionized water;
(g) immersing the at least one integrated circuit die into a first metal solution for a user-definable time, where the first metal solution is at a user-definable temperature;
(h) cleaning the at least one integrated circuit die in de-ionized water;
(i) immersing the at least one integrated circuit die into a second metal etchant solution for user-definable time;
(j) cleaning the at least one integrated circuit die in de-ionized water;
(k) immersing the at least one integrated circuit die into the first metal solution for a user-definable time, where the first metal solution is at a user-definable temperature;
(l) cleaning the at least one integrated circuit die in de-ionized water;
(m) plating a user-definable thickness of a second metal onto the padside of the at least one integrated circuit die;
(n) cleaning the at least one integrated circuit die in de-ionized water; and
(o) immersing the at least one integrated circuit die in a third metal solution for a user-definable time, where the third metal solution is at a user-definable temperature, and where the third metal solution is stirred at a user-definable rate.