Diamond membranes for X-ray lithography

Claim 1

A substantially compressive stress free, pin-holes and defects free, continuous polycrystalline diamond thin membrane for X-ray lithography; said polycrystalline diamond membrane being substantially optically and X-ray transparent and having a substantially uniform thickness generally in the range of approximately 0.5 μm to 4.0 μm.

Claim 11

A method for producing a substantially compressive stress free, pin-holes and defects free, continuous polycrystalline diamond X-ray membrane comprising: preparing the surface of a supporting substrate comprising a material selected from the group consisting of silicon, polysilicon, silicon carbide, silicon nitride, silicon oxynitride, boron carbide, boron nitride, alumina, titanium carbide, titanium nitride, tungsten, molybdenum, tantalum and mixtures thereof by treating said substrate surface with a slurry of diamond particles and a volatile solvent placed in an ultrasonic bath for a predetermined period of time; placing said substrate into a hot filament chemical vapor deposition reactor chamber; pre-heating said substrate by electrically charging the pre-carburized filament network of said reactor to a temperature in the range of about 400° C. to 650° C. in the presence of an inert gas; maintaining said pre-heating temperature for a predetermined period of time; heating said substrate to a temperature in the range of approximately 650° C.-700° C. in the presence of a gaseous mixture of flowing hydrogen and carbon compounds; chemically vapor depositing a substantially optically and X-ray transparent, adherent and coherent polycrystalline diamond membrane having a substantially uniform thickness onto said substrate; cooling said substrate by extinguishing said deposition process and passing an inert gas over said substrate until the temperature of said substrate has reached substantially room temperature during said cooldown step; removing said substrate coated with a substantially compressive stress free polycrystalline diamond X-ray membrane from said reactor; applying an etch resistant mask to the back surface of the said substrate to define one or more openings; etching said back surface of said substrate by preferential chemical etchant; and recovering said compressive stress free, pin-holes and defects free, continuous polycrystalline diamond membrane supported by a substrate frame.

Claim 12

A method for producing a substantially compressive stress free, pin-holes and defects free, continuous polycrystalline diamond X-ray membrane comprising: preparing the surface of a supporting substrate comprising a material selected from the group consisting of silicon, polysilicon, silicon carbide, silicon nitride, silicon oxynitride, boron carbide, boron nitride, alumina, titanium carbide, titanium nitride, tungsten, molybdenum, tantalum and mixtures thereof by treating said substrate surface with a slurry of diamond particles and a volatile solvent placed in an ultrasonic bath for a predetermined period of time; placing said substrate into a hot filament chemical vapor deposition reactor chamber; pre-heating said substrate by electrically charging the pre-carburized filament network of said reactor to a temperature in the range of about 400° C. to 650° C. in the presence of an inert gas; maintaining said pre-heating temperature for a predetermined period of time; heating said substrate to a temperature in the range of approximately 650° C.-700° C. in the presence of a gaseous mixture of flowing hydrogen and carbon compounds; chemically vapor depositing a substantially optically and X-ray transparent, adherent and coherent polycrystalline diamond membrane having a substantially uniform thickness onto said substrate; cooling said substrate by extinguishing said deposition process and passing an inert gas over said substrate until the temperature of said substrate has reached substantially room temperature during said cooldown step; removing said substrate coated with a substantially compressive stress free polycrystalline diamond X-ray membrane from said reactor; applying an etch resistant mask to the back surface of the said substrate to define one or more openings; etching said back surface of said substrate by preferential chemical etchant; and recovering said compressive stress free, pin-holes and defects free, continuous polycrystalline diamond membrane supported by a substrate frame.