US6265232B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Yield based, in-line defect sampling method
Assignee: Micron Technology Inc
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Filing: 1998-08-21
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Granted: 2001-07-24
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Expires: 2018-08-21
Abstract
Abstract A test method provides a sample of wafer level defects most likely to cause yield loss on a semiconductor wafer subdivided into a plurality of integrated circuits (IC's). Defect size and location data from an inspection tool is manipulated in an algorithm based on defect sizes and geometry parameters. The defects are classified by defect size to form size based populations The contribution of each size range of defect population to yield loss is calculated and random samples for review are selected from each defect size population. The number of samples from each size defect population is proportional to the predicted yield impact of each sample. The method is rapid and permits on-line process modification to reduce yield losses.
Inventors
- 👤 Steven J. Simmons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:32
CPC Classifications
H; H10; H10P; H10P74/00; H10P74/23; Y; Y02; Y02P; Y02P80/00; Y02P80/30
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
182 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting said integrated circuit semiconductor dice on said wafer to determine defects thereon and classifying each of said defects by size and location, said inspecting and classifying comprising classifying said each of said defects into one of size range populations of defects; assigning a weight to said each of said defects representing an estimated effect of said each of said defects on die yield for said integrated circuit semiconductor dice; determining an estimated die yield loss (DYL) for each die of said integrated circuit semiconductor dice based on number and weight of said defect(s) on each said die; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects for said integrated circuit semiconductor dice; and determining a relative contribution of each size range population of defects of said plurality for said integrated circuit semiconductor dice to wafer yield loss WYL.
Claim 2
Independent Claim
182 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting said integrated circuit semiconductor dice on said wafer to determine defects thereon and classifying each of said defects by size and location, said inspecting and classifying comprising classifying said each of said defects into one of size range populations of defects; assigning a weight to said each of said defects representing an estimated effect of said each of said defects on die yield for said integrated circuit semiconductor dice; determining an estimated die yield loss (DYL) for each die of said integrated circuit semiconductor dice based on number and weight of said defect(s) on each said die; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects for said integrated circuit semiconductor dice; and determining a relative contribution of each size range population of defects of said plurality for said integrated circuit semiconductor dice to wafer yield loss WYL.
Claim 3
Dependent Claim
31 words
The method of claim 1 , wherein said determining said estimated die yield loss comprises calculating an estimated die yield loss having lower and upper limits of zero and 1.0, respectively.
Claim 4
Dependent Claim
36 words
The method of claim 2 , wherein said lower limit comprises a representation of no yield loss attributable to said defects and said upper limit comprises a representation of fatal yield loss attributable to said defect.
Claim 5
Dependent Claim
35 words
The method of claim 1 , wherein said determining said estimated die yield loss (DYL) comprises calculating an estimated die yield loss having a lower limit and an upper limit of zero and 1.0, respectively.
Claim 6
Dependent Claim
34 words
The method of claim 1 , wherein said subdividing said defects into said plurality of size range populations of defects comprises subdividing side defects into a plurality of 0 to 10 size range populations.
Claim 7
Independent Claim
253 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting said integrated circuit semiconductor dice on said wafer to determine defects thereon and classifying each of said defects by size and location, said inspecting and classifying comprising classifying said each of said defects into one of size range populations of defects; assigning a weight to said each of said defects representing an estimated effect of said defects on die yield for said integrated circuit semiconductor dice; determining an estimated die yield loss (DYL) for each die of said integrated circuit semiconductor dice based on number and weight of said defect(s) on said each die; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects; and determining a relative contribution of each size range population of defects of said plurality to wafer yield loss WYL, said determining the relative contribution of said each size range population of defects of said plurality to wafer yield loss comprises: discarding data for said each size range population of defects of said plurality and calculating, in turn, a drop in wafer yield loss for combined size range populations excepting the discarded data; summing the calculated wafer yield losses to obtain a drop sum; and dividing said drop sum to determine a relative drop attributable to said each size range population of defects of said plurality.
Claim 8
Independent Claim
253 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting said integrated circuit semiconductor dice on said wafer to determine defects thereon and classifying each of said defects by size and location, said inspecting and classifying comprising classifying said each of said defects into one of size range populations of defects; assigning a weight to said each of said defects representing an estimated effect of said defects on die yield for said integrated circuit semiconductor dice; determining an estimated die yield loss (DYL) for each die of said integrated circuit semiconductor dice based on number and weight of said defect(s) on said each die; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects; and determining a relative contribution of each size range population of defects of said plurality to wafer yield loss WYL, said determining the relative contribution of said each size range population of defects of said plurality to wafer yield loss comprises: discarding data for said each size range population of defects of said plurality and calculating, in turn, a drop in wafer yield loss for combined size range populations excepting the discarded data; summing the calculated wafer yield losses to obtain a drop sum; and dividing said drop sum to determine a relative drop attributable to said each size range population of defects of said plurality.
Claim 9
Dependent Claim
59 words
The method of claim 1 , further comprising: randomly selecting defects from said each size range population of defects of said plurality, a number selected from said each size range population of defects of said plurality in proportion to said relative contribution thereof, whereby said randomly selected defects are weighted to represent defects having greatest effect on yield losses.
Claim 10
Dependent Claim
23 words
The method of claim 7 , further comprising: reviewing said randomly selected defects and determining in-line action required to reduce wafer yield losses.
Claim 11
Dependent Claim
26 words
The method of claim 8 , wherein said reviewing said randomly selected defects includes visual inspection by one of a scanning microscope and an optical microscope.
Claim 12
Dependent Claim
28 words
The method of claim 9 , wherein said determining in-line action comprises determining if an individual die on said wafer is acceptable to proceed in said manufacturing process.
Claim 13
Dependent Claim
19 words
The method of claim 1 , wherein said inspecting said dice is performed by an automated surface inspection tool.
Claim 14
Independent Claim
190 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting on said wafer to determine defects thereon and classifying each of said defects by size and location; assigning a weight to said each of said defects representing an estimated effect of said each of said defects on die yield; determining an estimated die yield loss (DYL) for each die based on number and weight of said defect(s) on said each said die of said integrated circuit semiconductor dice; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects; determining a relative contribution of each size range population of defects of said plurality to wafer yield loss WYL; and randomly selecting defects from said each size range population of defects of the plurality, a number selected from said each size range population of defects of the plurality in proportion to said relative contribution thereof, said randomly selected defects weighted to represent defects having greatest effect on yield losses.
Claim 15
Independent Claim
190 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting on said wafer to determine defects thereon and classifying each of said defects by size and location; assigning a weight to said each of said defects representing an estimated effect of said each of said defects on die yield; determining an estimated die yield loss (DYL) for each die based on number and weight of said defect(s) on said each said die of said integrated circuit semiconductor dice; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects; determining a relative contribution of each size range population of defects of said plurality to wafer yield loss WYL; and randomly selecting defects from said each size range population of defects of the plurality, a number selected from said each size range population of defects of the plurality in proportion to said relative contribution thereof, said randomly selected defects weighted to represent defects having greatest effect on yield losses.
Claim 16
Dependent Claim
23 words
The method of claim 12 , further comprising: reviewing said randomly selected defects and determining in-line action required to reduce wafer yield losses.
Claim 17
Dependent Claim
32 words
The method of claim 12 , wherein said inspecting said dice and classifying said defects comprises classifying each of said defects into one of said plurality of size range populations of defects.
Claim 18
Dependent Claim
31 words
The method of claim 12 , wherein said determining said estimated die yield loss comprises calculating an estimated die yield loss having lower and upper limits of zero and 1.0, respectively.
Claim 19
Dependent Claim
36 words
The method of claim 15 , wherein said lower limit comprises a representation of no yield loss attributable to said defects and said upper limit comprises a representation of fatal yield loss attributable to said defects.
Claim 20
Dependent Claim
34 words
The method of claim 12 , wherein said subdividing said defects into said plurality of size range populations of defects comprises subdividing said defects into a plurality of 0 to 10 size range populations.
Claim 21
Dependent Claim
95 words
The method of claim 12 , wherein said determining the relative contribution of said each size range population of defects of said plurality to wafer yield loss comprises: discarding data for said each size range population of defects of said plurality and calculating, in turn, a drop in wafer yield loss for combined size range populations excepting the discarded data; summing the calculated drop in wafer yield losses to obtain a drop sum; and dividing said drop sum to determine a relative drop attributable to said each size range population of defects of said plurality.
Claim 22
Dependent Claim
26 words
The method of claim 13 , wherein said reviewing said randomly selected defects includes visual inspection by one of a scanning microscope and an optical microscope.
Claim 23
Dependent Claim
34 words
The method of claim 13 , wherein said determining in-line action required to reduce wafer yield losses comprises determining if an individual die on said wafer is acceptable to proceed in said manufacturing process.
Claim 24
Dependent Claim
19 words
The method of claim 12 , wherein said inspecting said dice is performed by an automated surface inspection tool.
Claim 25
Independent Claim
224 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting said dice on said wafer to determine defects thereon and classifying each of said defects by size and location, said inspecting and classifying comprises classifying said each of said defects into one of size range populations of defects; assigning a weight to said each of said defects representing an estimated effect of said each of said defects on die yield; determining an estimated die yield loss (DYL) for each die based on number and weight of said defect(s) on said each die of said integrated circuit semiconductor dice; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects; determining a relative contribution of each size range population of defects of said plurality to wafer yield loss WYL; randomly selecting defects from each size range population of defects of the plurality, a number selected from said each size range population of defects of the plurality in proportion to said relative contribution thereof, said randomly selected defects weighted to represent defects having greatest effect on yield losses; and reviewing said randomly selected defects and determining in-line action required to reduce wafer yield losses.
Claim 26
Independent Claim
224 words
A method for processing integrated circuit semiconductor dice on a wafer in a manufacturing process for said dice, said method comprising: inspecting said dice on said wafer to determine defects thereon and classifying each of said defects by size and location, said inspecting and classifying comprises classifying said each of said defects into one of size range populations of defects; assigning a weight to said each of said defects representing an estimated effect of said each of said defects on die yield; determining an estimated die yield loss (DYL) for each die based on number and weight of said defect(s) on said each die of said integrated circuit semiconductor dice; summing all DYL of said integrated circuit semiconductor dice on said wafer to obtain a wafer yield loss (WYL); subdividing the defects into a plurality of size range populations of defects; determining a relative contribution of each size range population of defects of said plurality to wafer yield loss WYL; randomly selecting defects from each size range population of defects of the plurality, a number selected from said each size range population of defects of the plurality in proportion to said relative contribution thereof, said randomly selected defects weighted to represent defects having greatest effect on yield losses; and reviewing said randomly selected defects and determining in-line action required to reduce wafer yield losses.
Claim 27
Dependent Claim
31 words
The method of claim 22 , wherein said determining said estimated die yield loss comprises calculating an estimated die yield loss having lower and upper limits of zero and 1.0, respectively.
Claim 28
Dependent Claim
36 words
The method of claim 23 , wherein said lower limit comprises a representation of no yield loss attributable to said defects and said upper limit comprises a representation of fatal yield loss attributable to said defects.
Claim 29
Dependent Claim
34 words
The method of claim 22 , wherein said subdividing said defects into said plurality of size range populations of defects comprises subdividing said defects into a plurality of 0 to 10 size range populations.
Claim 30
Dependent Claim
96 words
The method of claim 22 , wherein said determining the relative contribution of said each size range population of defects of said plurality to wafer yield loss comprises: discarding data for said each size range population of defects of said plurality and calculating, in turn, a drop in wafer yield loss for combined size range populations excepting the discarded data; summing the calculated drop in wafer yield losses to obtain a drop sum; and dividing said drop sum to determine a relative drop sum attributable to said each size range population of defects of said plurality.
Claim 31
Dependent Claim
26 words
The method of claim 23 , wherein said reviewing said randomly selected defects includes visual inspection by one of a scanning microscope and an optical microscope.
Claim 32
Dependent Claim
28 words
The method of claim 23 , wherein said determining in-line action comprises determining if an individual die on said wafer is acceptable to proceed in said manufacturing process.
Claim 33
Dependent Claim
19 words
The method of claim 28 , wherein said inspecting said dice is performed by an automated surface inspection tool.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-07-23 | 2005-01-22 | 2005-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-07-23 | 2009-01-22 | 2009-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-07-23 | 2013-01-22 | 2013-07-24 | $7700.00 | Window Closed / Lapsed |