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US 5,705,435 AGranted
Chemical-mechanical polishing (CMP) apparatus
AssigneeIndustrial Technology Research Institute
InventorLai-Tuh Chen
Life of this patent
Estimating the term…
Abstract
An improved and new apparatus and process for chemical-mechanical polishing (CMP) the surface of a semiconductor substrate to a planar condition has beed developed. The planarization endpoint, which is independent of topographic pattern density, is detected by monitoring the ratio of the rate of insulator material removal over a pattern feature to the rate of insulator material removal over an area without an underlying pattern feature.
Claims38
An apparatus for planarizing semiconductor substrates comprising:
- a rotatable platen and polishing pad for chemical-mechanical polishing (CMP) an insulating layer deposited over a metallization pattern formed on the surface of a semiconductor substrate;
- a reservoir for a polishing slurry and means to dispense the slurry onto the polishing pad;
- a rotatable substrate carrier and means for holding the surface of the semiconductor substrate in juxtaposition relative to said rotatable platen and polishing pad with an applied pressure between the rotatable substrate carrier and the rotatable platen and polishing pad;
- a means to transfer the semiconductor substrate from the rotatable substrate carrier to an in-line cleaning station comprising a water spray nozzle and an air spray nozzle;
- a means to transfer the semiconductor substrate from the in-line cleaning station to an in-line optical thickness measurement tool;
- a means to align the semiconductor substrate in the in-line optical thickness measurement tool;
- a means to measure the thickness of the insulating layer over said metallization pattern before and after polishing;
- a means to measure the thickness of the insulating layer over said semiconductor substrate before and after polishing;
- a means to compute a first polish removal rate of said insulating layer over said metallization pattern;
- a means to compute a second polish removal rate of said insulating layer over said semiconductor substrate;
- a means of computing a polish removal rate ratio by dividing said first polish removal rate by said second polish removal rate;
- and
- a means to transfer the semiconductor substrate from the in-line optical thickness measurement tool to the rotatable substrate carrier for additional chemical-mechanical polishing (CMP) until said polish removal rate ratio is less than between about 0.9 to 1.1.
10 more elements
A method of chemical-mechanical polishing (CMP) a semiconductor substrate comprising:
- depositing a first insulating layer on said semiconductor substrate;
- forming a metallization pattern on said first insulating layer;
- conformally depositing a second insulating layer over said first insulating layer and said metallization pattern;
- measuring the thickness of said second insulating layer over said metallization pattern;
- measuring the combined thicknesses of said second insulating layer and said first insulating layer over said semiconductor substrate;
- performing chemical-mechanical polishing (CMP) of said second insulating layer;
- transferring said semiconductor substrate to an in-line cleaning station comprising a water spray nozzle and an air spray nozzle;
- removing the polishing slurry from the semiconductor substrate with water from said water spray nozzle;
- drying the semiconductor substrate with air from said air spray nozzle;
- transferring said semiconductor substrate to an in-line optical thickness measurement tool;
- aligning said semiconductor substrate in said in-line optical thickness measurement tool;
- remeasuring, after chemical-mechanical polishing (CMP), the thickness of said second insulating layer over said metallization pattern;
- remeasuring, after chemical-mechanical polishing (CMP), the combined thicknesses of said second insulating layer and said first insulating layer over said semiconductor substrate;
- computing a first polish removal rate of said second insulating layer over said metallization pattern;
- computing a second polish removal rate of said second insulating layer over said semiconductor substrate;
- computing a polish removal rate ratio by dividing said first polish removal rate by said second polish removal rate;
- and
- performing additional chemical-mechanical polishing (CMP) until said polish removal rate ratio is less than between about 0.9 to 1.1.
15 more elements
A method of chemical-mechanical polishing (CMP) a semiconductor substrate comprising:
- depositing a first insulating layer on said semiconductor substrate;
- forming a metallization pattern on said first insulating layer;
- conformally depositing a second insulating layer over said first insulating layer and said metallization pattern;
- measuring the thickness of said second insulating layer over said metallization pattern;
- measuring the combined thicknesses of said second insulating layer and said first insulating layer over said semiconductor substrate;
- performing chemical-mechanical polishing (CMP) of said second insulating layer;
- transferring said semiconductor substrate to an in-line cleaning station comprising a water spray nozzle and an air spray nozzle;
- removing the polishing slurry from the semiconductor substrate with water from said water spray nozzle;
- drying the semiconductor substrate with air from said air spray nozzle;
- transferring said semiconductor substrate to an in-line optical thickness measurement tool;
- aligning said semiconductor substrate in said in-line optical thickness measurement tool;
- remeasuring, after chemical-mechanical polishing (CMP), the thickness of said second insulating layer over said metallization pattern;
- remeasuring, after chemical-mechanical polishing (CMP), the combined thicknesses of said second insulating layer and said first insulating layer over said semiconductor substrate;
- computing a first polish removal rate of said second insulating layer over said metallization pattern;
- computing a second polish removal rate of said second insulating layer over said semiconductor substrate;
- computing a polish removal rate ratio by dividing said second polish removal rate by said first polish removal rate;
- and
- performing additional chemical-mechanical polishing (CMP) until said polish removal rate ratio is greater than between about 0.9 to 1.1.
15 more elements
Dependencies are inferred from the claim text.