Bump reflow method by inert gas plasma

A method of forming reflowed bumps, comprising the sequential steps of:

• providing a wafer;
• forming a series of spaced initial bumps upon the wafer;
• the initial bumps having exposed side walls and top surfaces and organic residue over the initial bump side walls and/or the initial bump top surfaces;
• using an oxygen gas plasma treatment to simultaneously removing the organic residue from the initial bump side walls and top surfaces and forming a surface oxide layer over the initial bump side walls and top surfaces;
• using a gas or an inert plasma gas treatment to strip the surface oxide layer from the initial bump top surfaces and an upper portion of the initial bump side walls to form partially exposed bumps;
• and
• using a gas or an inert gas heating treatment to melt the partially exposed bumps to form the reflowed bumps.

A method of forming reflowed bumps, comprising the sequential steps of:

• providing a wafer;
• forming a series of spaced initial bumps upon the wafer;
• the initial bumps having exposed side walls and top surfaces and organic residue over the initial bump side walls and/or the initial bump top surfaces;
• using an oxygen gas plasma treatment to simultaneously removing the organic residue from the initial bump side walls and top surfaces and forming a surface oxide layer over the initial bump side walls and top surfaces;
• using a gas or an inert plasma gas treatment to strip the surface oxide layer from the initial bump top surfaces and an upper portion of the initial bump side walls to form partially exposed bumps;
• the inert gas plasma treatment including an inert gas selected from the group consisting of:
• nitrogen;
• argon;
• and an nitrogen/hydrogen forming gas;
• and
• using a gas or an inert gas heating treatment to reflow the exposed portions of the partially exposed bumps to form the reflowed bumps;
• the inert gas heating treatment includes a gas selected from the group consisting of:
• nitrogen, argon and nitrogen/hydrogen.

A method of forming reflowed bumps, comprising the sequential steps of:

• providing a wafer;
• forming a series of spaced initial bumps upon the wafer;
• the initial bumps having exposed side walls and top surfaces;
• forming a surface native oxide layer over the initial bump side walls and top surfaces;
• stripping the surface native oxide layer from the initial bump top surfaces and an upper portion of the initial bump side walls to form partially exposed bumps;
• each of the bumps having a lower portion covered by the remaining surface native oxide;
• and
• heat treating the partially exposed bumps to melt the partially exposed bumps to form the reflowed bumps.