Electroless Ni plating on n- and p-type porous Si for ohmic and rectifying contacts

The properties of electrical contacts made on porous Si by the electroless Ni plating technique have been studied. It is shown that due to the pore infiltration property of the plating solution, metallization occurs inside the pores over an effective area several times higher than the physical area of the sample. By making variations in the plating bath composition, Ni containing a small amount of P or B as an impurity is plated and excellent ohmic or rectifying contacts on n- or p-type porous Si are obtained. It is further observed that a higher area of contact with comparatively superior electrical properties is obtained when electroless Ni plating is made from the bath which introduces B as the impurity.