BACKSIDE GETTERING OF CU BY POROUS SI

Porous Si can act as a getter for Cu. In this experiment, Cu was depos ited on the front surface of a Si wafer, after a part of the back surf ace of the same wafer had been rendered porous. Following a vacuum ann eal treatment(900 degrees C, 2 h), ion scattering shows that some Cu h as diffused through the Si wafer and that up to 0.8 x 10(16) atoms cm( -2) can be gettered in the porous Si layer opposite the deposited Cu.