1. A method for forming a semiconductor device including a resistive memory cell, the method comprising: providing a substrate having an upper surface; forming a first conductive layer over the upper surface of the substrate; forming a resistive switching material layer over the first conductive layer, wherein the resistive switching material comprises an intrinsic semiconductor; cleaning a surface of the resistive switching material layer to remove native oxide formed on the surface of the resistive switching material layer; depositing a silver layer over the resistive switching material layer after removing the native oxide by performing the cleaning step, wherein the resistive memory cell includes the first conductive layer, the resistive switching material layer, and the silver layer, and wherein the surface of the resistive switching material layer is cleaned to reduce agglomeration of silver.