Method and apparatus for low-temperature annealing of metallization microstructures in the production of a microelectronic device
First Claim
1. A method for reducing voids in a metal material that has been electrolytically deposited into recessed microstructures defined in a surface of a microelectronic workpiece comprising:
- electrolytically depositing a metal to substantially fill recessed sub-micron structures in the surface of the workpiece; and
thensubjecting the workpiece to an annealing process at a temperature that is at or below about 250 degrees Celsius, the workpiece being subjected to a controlled temperature gradient in which the temperature decreases along a cross-section of the workpiece in a direction that is opposite to the direction of formation of the metal material during its deposition.
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Accused Products
Abstract
A method for filling recessed microstructures at a surface of a microelectronic workpiece, such as a semiconductor wafer, with metallization is set forth. In accordance with the method, a metal layer is deposited into the microstructures with a process, such as an electroplating process, that generates metal grains that are sufficiently small so as to substantially fill the recessed microstructures. The deposited metal is subsequently subjected to an annealing process at a temperature below about 100 degrees Celsius, and may even take place at ambient room temperature to allow grain growth which provides optimal electrical properties. Various novel apparatus for executing unique annealing processes are also set forth.
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Citations
102 Claims
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1. A method for reducing voids in a metal material that has been electrolytically deposited into recessed microstructures defined in a surface of a microelectronic workpiece comprising:
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electrolytically depositing a metal to substantially fill recessed sub-micron structures in the surface of the workpiece; and
thensubjecting the workpiece to an annealing process at a temperature that is at or below about 250 degrees Celsius, the workpiece being subjected to a controlled temperature gradient in which the temperature decreases along a cross-section of the workpiece in a direction that is opposite to the direction of formation of the metal material during its deposition. - View Dependent Claims (2, 3, 4)
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5. A method for reducing voids in a metal material that has been electrolytically deposited into recessed microstructures defined on a surface of a microelectronic workpiece comprising:
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electrolytically depositing a metal to substantially fill recessed sub-micron structures on the surface of the workpiece; and
thensubjecting the workpiece to an annealing process to generate a controlled temperature gradient in which the temperature decreases along a cross-section of the workpiece in a direction that is toward the surface in which the recessed sub-micron structures are formed. - View Dependent Claims (6)
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7. A method of processing a microelectronic workpiece having a surface including a sub-micron recessed microstructure, comprising:
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electroplating copper at an electroplating station to substantially fill the recessed microstructure and to deposit excess copper above the recessed microstructure; thereafter, robotically transferring the workpiece from the electroplating station for at least one further process that includes thermal processing at a thermal processing station, the thermal processing comprising thermally treating the electroplated copper by establishing a temperature gradient through the electroplated copper having a maximum gradient temperature of about 60 degrees Celsius to about 100 degrees Celsius for no longer than 15 minutes, thereby reducing resistivity of the copper and reducing voids which may be present in the copper. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of treating a workpiece having a base having a surface, a dielectric layer carried on the surface of the base, and recessed sub-micron structures formed in the dielectric layer, comprising:
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depositing a conductive seed layer exterior to the dielectric layer and in the recessed sub-micron structures; contacting the seed layer with a copper-containing electroplating solution; applying electroplating power to the seed layer to electrolytically deposit copper metal from the electroplating solution to substantially fill the recessed sub-micron structures and to deposit excess copper metal which extends beyond an exterior surface of the dielectric layer;
thensubjecting the electroplated workpiece to an elevated temperature annealing process comprising establishing a temperature gradient in which the temperature decreases in a direction moving outwardly from the base toward the dielectric layer, the annealing process having a maximum gradient temperature which is no greater than about 250 degrees Celsius. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method of treating a microelectronic workpiece having a base having a surface including a sub-micron recessed microstructure, comprising:
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contacting the surface of the workpiece with a copper-containing electroplating solution; applying electroplating power at a first power level for a first period of time, then applying electroplating power at a higher second power level for a time sufficient to substantially fill the recessed sub-micron structures with electroplated copper metal and to deposit excess copper metal above the sub-micron recessed microstructures;
thensubjecting the electroplated workpiece to an elevated temperature annealing process comprising establishing a temperature gradient through the electroplated copper metal in which the temperature decreases in a direction moving outwardly from the base toward the workpiece surface, the annealing process having a maximum gradient temperature which is no greater than about 250 degrees Celsius. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45)
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46. A method of treating a microelectronic workpiece having a base having a surface including a sub-micron recessed microstructure, comprising:
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contacting the surface of the workpiece with a copper-containing electroplating solution; applying electroplating power to the workpiece in a pulsed waveform having a frequency of between about 1 and 1000 Hz to substantially fill the recessed sub-micron structures with electroplated copper metal and to deposit excess copper metal above the sub-micron recessed microstructures;
thensubjecting the electroplated workpiece to an elevated temperature annealing process comprising establishing a temperature gradient through the electroplated copper in which the temperature decreases in a direction moving outwardly from the base toward the surface of the workpiece, the temperature gradient having a maximum gradient temperature which is no greater than about 250 degrees Celsius. - View Dependent Claims (47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60)
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61. A method of processing a microelectronic workpiece having a surface including a sub-micron recessed microstructure and a conductive seed layer in the sub-micron recessed microstructure, comprising:
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electroplating copper at an electroplating station to substantially fill the recessed microstructure and to deposit excess copper which extends above the sub-micron recessed microstructure; robotically transferring the workpiece from the electroplating station for further processing; removing the excess copper as one of the further processes; and thereafter, robotically transferring the workpiece to a thermal processing station to thermally treat the electroplated copper by establishing a temperature gradient in the electroplated copper having a maximum temperature of about 60 degrees Celsius to about 100 degrees Celsius for no longer than 15 minutes, thereby reducing resistivity of the copper and reducing voids which may be present in the copper. - View Dependent Claims (62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72)
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73. A method of treating a microelectronic workpiece having a base having a surface including a sub-micron recessed microstructure, comprising:
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contacting the surface of the workpiece with a copper-containing electroplating solution; applying electroplating power at a first power level for a first period of time, then applying electroplating power at a higher second power level for a time sufficient to substantially fill the recessed sub-micron structures with electroplated copper metal and to deposit excess copper metal above the sub-micron recessed microstructures;
thensubjecting the electroplated workpiece to an elevated temperature annealing process for a time sufficient to reduce resistivity of the electroplated copper metal. - View Dependent Claims (74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86)
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87. A method of treating a microelectronic workpiece having a base having a surface including a sub-micron recessed microstructure, comprising:
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contacting the surface of the workpiece with a copper-containing electroplating solution; applying electroplating power to the workpiece in a pulsed waveform having a frequency of between about 1 and 1000 Hz to substantially fill the recessed sub-micron structures with electroplated copper metal and to deposit excess copper metal above the sub-micron recessed microstructures;
thensubjecting the electroplated workpiece to an elevated temperature annealing process for a time sufficient to reduce resistivity of the electroplated copper metal. - View Dependent Claims (88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102)
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Specification