Patterned metallization of porous silicon from electroless solution for direct electrical contact

The excitation of the triplet exciton leading to the "long-lived" photolumi nescence characteristic of a porous silicon (PS) surface has bran used to s electively enhance the highly efficient, controlled, and patterned plating of copper and silver metal from electroless solutions. The basis of this me thod lies in the use of the "long-lived" excited state to promote an enhanc ed reduction at the PS surface. Excited fluorophors, created at the PS surf ace, using a Xe are lamp or HeNe laser, exhibit an interaction and reductio n capability absent without optical pumping. The thickness of the metal dep osit is proportional to the time and intensity of exposure and the contact resistance can be made less than 500 Omega. (C) 2000 The Electrochemical So ciety. S0013-4651(00)03-117-7. All rights reserved.