Pretreatment liquid of electroless plating onto semiconductor wafer, electroless plating method, and semiconductor device

TLDR: In this paper, the authors proposed a pretreatment liquid for electroless plating of nickel or an nickel alloy onto a semiconductor wafer in which n-type and p-type semiconductors are mixed.

Abstract: PROBLEM TO BE SOLVED: To provide a pretreatment liquid for performing electroless plating of nickel or an nickel alloy onto a semiconductor wafer in which n-type and p-type semiconductors are mixed.SOLUTION: The pretreatment liquid of electroless plating is an aqueous solution composed of hydrogen peroxide water, ammonia water and/or tetramethyl ammonium hydroxide (TMAH). When transistor electrodes in which n-type and p-type semiconductors are mixed such as a source and drain electrodes of FET are formed, impurities on a surface of a silicon substrate can be effectively removed or reduced and the surface of the silicon substrate can be activated with the use of the pretreatment liquid of electroless plating. When n-type and p-type semiconductors are mixed in such a silicon substrate, after treatment by the liquid is performed, the pretreatment liquid is adaptable to a subsequent electroless Ni or Ni alloy plating, and thus uniform electroless plating can be performed.