Method For Low Temperature Bonding And Bonded Structure

Abstract

A method for bonding at low or room temperature includes steps of surface cleaning and activation by cleaning or etching. The method may also include removing by-products of interface polymerization to prevent a reverse polymerization reaction to allow room temperature chemical bonding of materials such as silicon, silicon nitride and SiO 2 . The surfaces to be bonded are polished to a high degree of smoothness and planarity. VSE may use reactive ion etching or wet etching to slightly etch the surfaces being bonded. The surface roughness and planarity are not degraded and may be enhanced by the VSE process. The etched surfaces may be rinsed in solutions such as ammonium hydroxide or ammonium fluoride to promote the formation of desired bonding species on the surfaces.

1 . A bonding method, comprising:
 forming first and second bonding surfaces on first and second materials, respectively, at least one of said surfaces comprising an insulating material;   enhancing activation of one of said first and second bonding surfaces;   terminating said first and second bonding surfaces with a species allowing formation of chemical bonds;   bringing together said first and second bonding materials;   removing a substantial portion of said first material to leave a remaining portion;   forming a third bonding surface on said remaining portion;   enhancing activation of one of said third bonding surface and a fourth surface of a third material;   bringing together said third bonding surface with said fourth surface; and   forming a chemical bond between said remaining portion and said third material.