Patent ID: 7879704

Claim:
A particle forming method, comprising: implanting by an ion implantation method a substance for forming one or more conductive particles into a first insulator and at a prescribed depth of implantation; performing a heat treatment to form conductive particles from the substance implanted in the first insulator; performing an etching process to the first insulator to remove a region from a top surface of the first insulator to a depth equal to or more than the prescribed depth of implantation; and performing a heat treatment in an oxidizing atmosphere or a nitriding atmosphere either prior to or after the etching process to make a periphery of each conductive particle insulative to thereby form a second insulator, wherein a plurality of particles, each of which is made of a conductive particle and a second insulator that covers the conductive particle, are formed such that particles closer to a top surface of the remaining first insulator are larger in particle diameter and in thickness of the second insulator than particles farther from the top surface of the remaining first insulator.