On-site ammonia purification for semiconductor manufacture
AssigneeStartec Ventures, Inc.
InventorsJoe G. Hoffman, R. Scott Clark
Life of this patent
Estimating the term…
Abstract
Highly purified ammonia for use in semiconductor manufacturing is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous scrubber.
Claims39
An on-site subsystem, in a semiconductor device fabrication facility, for providing ultra-high-purity reagents comprising ammonia to a semiconductor manufacturing operation, comprising:
- an evaporation source connected to receive a liquid ammonia source and to provide a flow of ammonia vapor therefrom;
- said flow of ammonia vapor being connected to pass through an ionic purifier unit which provides a recirculating volume of high-purity water, containing a high concentration of ammonium hydroxide, in contact with said flow of ammonia vapor;
- a generator unit, connected to receive said flow of ammonia vapor from said purifier unit and to combine said ammonia vapor with an aqueous liquid to produce an ultra-pure aqueous solution comprising ammonia;
- and
- a piping connection which routes said aqueous solution to at least one point of use in the semiconductor device fabrication facility.
An on-site subsystem, in a semiconductor device fabrication facility, for providing ultra-high-purity reagents comprising ammonia to a semiconductor manufacturing operation, comprising:
- an evaporation source connected to receive a liquid ammonia source and to provide a flow of ammonia vapor therefrom;
- said flow of ammonia vapor being connected to pass through an ionic purifier unit which provides a recirculating volume of high-purity water, containing a high concentration of ammonium hydroxide, in contact with said flow of ammonia vapor;
- and
- a generator unit, connected to receive said flow of ammonia vapor from said purifier unit and to combine said ammonia vapor with an aqueous liquid to produce an ultra-pure aqueous solution comprising ammonia;
- whereby said ultra-pure aqueous solution can be used within the semiconductor device fabrication facility without bulk transfer or exposure of liquid surface to any uncontrolled atmosphere.
An on-site subsystem, in a semiconductor device fabrication facility, for providing ultra-high-purity ammonia for use in semiconductor manufacturing operations at said facility, comprising:
- an evaporation source connected to receive a liquid ammonia source and to provide a flow of ammonia vapor therefrom;
- said flow of ammonia vapor being connected to pass through an ionic purifier unit which provides a recirculating volume of high-purity water, containing a high concentration of ammonium hydroxide, in contact with said flow of ammonia vapor;
- a dryer unit, connected to receive said flow of ammonia vapor from said purifier unit and to dry said vapor from said purifier unit;
- and
- a piping connection which routes said vapor from said dryer unit to at least one point of use in the semiconductor device fabrication facility.
A system for the preparation of ultra-high purity ammonia, said system comprising:
- (a) a reservoir of liquid ammonia with a vapor space above said liquid;
- (b) a connection for drawing vapor containing ammonia gas from said vapor space;
- (c) a filtration membrane adapted to remove particles from vapor thus drawn;
- (d) an ionic purifier unit in which filtered vapor emanating from said filtration membrane is contacted with an aqueous solution of ammonia in deionized water to produce a purified ammonia gas;
- and
- (e) an outlet for removing said purified ammonia gas from said ionic purifier unit.
A system for the manufacture of high-precision electronic components, said system comprising:
- (a) a production line containing a plurality of workstations arranged to perform various respective steps, on wafers containing semiconductor material, in manufacture of an electronic component, at least one of said workstations using gaseous ammonia as a source gas for operation on to said workpiece;
- and
- (b) a purification subunit connected to said at least one of said workstations by piping to supply said gaseous ammonia in ultra-high purity form, said subunit comprising:
- (i) a reservoir of liquid ammonia with a vapor space above said liquid ammonia;
- (ii) a connection for drawing vapor containing ammonia gas from said vapor space;
- (iii) a filtration membrane for removing particles from vapor thus drawn;
- and
- (iv) an ionic purifier unit arranged to contact filtered vapor having passed through said filtration membrane with an aqueous solution of ammonia in deionized water, the vapor emerging from said ionic purifier unit being purified ammonia gas.
A method for supplying a high-purity ammonia reagent to a workstation in a production line for the manufacture of a high-precision electronic component, said method comprising:
- (a) drawing ammonia gas from a vapor space above liquid ammonia in an ammonia-containing reservoir;
- (b) passing said ammonia gas through a filtration membrane to remove particles greater than 0.005 micron therefrom;
- (c) passing said ammonia gas thus filtered through an ionic purifier unit whereby said ammonia gas is contacted with an aqueous solution of ammonia in deionized water;
- and
- (d) recovering said ammonia gas emerging from said ionic purifier unit and directing said ammonia gas to said workstation.
A system for the preparation of ultra-high-purity ammonia, comprising:
- an evaporation source connected to receive a liquid ammonia source and to provide a flow of ammonia vapor therefrom;
- said flow of ammonia vapor being connected to pass through a unit which provides a recirculating volume of high-purity water, containing a high concentration of ammonium hydroxide, in contact with said flow of ammonia vapor, to produce a purified ammonia gas;
- said unit having an outlet for removing said purified ammonia gas emerging from said unit.
Dependencies are inferred from the claim text.