Method of making a diode read/write memory cell in a programmed state

A method of making a diode, comprising:

• forming a first electrode;
• forming a semiconductor region in electrical contact with the first electrode, wherein the semiconductor region comprises a p-n or a p-i-n junction in at least one silicon, germanium or silicon-germanium layer;
• forming a titanium layer on the semiconductor region;
• forming a titanium nitride layer on the titanium layer;
• reacting the titanium layer with the semiconductor region to form a titanium silicide, titanium germanide, or titanium silicide-germanide layer on the semiconductor region;
• removing the titanium nitride layer and a remaining portion of the titanium layer after the step of reacting;
• and
• forming a second electrode in electrical contact with the titanium silicide, titanium germanide or titanium silicide-germanide layer.