Methodology for proper weighting of photolithography in the cost of semiconductor products

• US 6,249,776 B1
• Filed: 09/22/1998
• Issued: 06/19/2001
• Est. Priority Date: 09/22/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Miller, Peter J., Miraglia, Stephanie A., Blouin, Cathy L., McAuliffe, Daniel A., Juba, Robert C., Bajuk, Stanislav P., Blunt, Gregory A., Boldman, Gary D., Richardson, Thomas C.
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US09/158,268
• Time in Patent Office: 1,001 Days
• Field of Search: 705/1, 705/7, 705/29, 705/30, 705/400, 707/104
• US Class Current: 705/400
• CPC Class Codes: G06Q 10/04 Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem" market predictions or forecasting for commercial activities G06Q30/0202
• CPC Class Codes: G06Q 30/0201 Market modelling; Market analysis; Collecting market data
• CPC Class Codes: G06Q 30/0283 Price estimation or determination

Abstract

A method of, computer system for, and computer program product for causally relating costs to products, including relating costs to a wafer having semiconductor chips comprising identifying resource costs for manufacturing the wafer including identifying equipment costs, computing load factors for each of the resource costs (the computing load factors for the equipment costs comprising determining a number of exposure fields on the wafer, computing a raw processing time for the wafer based on the number of exposure fields, and determining a percentage the raw processing time represents of a manufacturing time period on an equipment element, the equipment element having the equipment costs), producing weighted resource costs based on the resource costs and the load factors, (the producing weighted resource costs for the equipment costs comprising multiplying the equipment costs by the percentage), summing the weighted resource costs for the wafer, determining a volume of the wafer manufactured, and dividing the weighted resource costs by the volume to produce a weighted cost per wafer.

Claims

1. A method of causally relating costs to a wafer having semiconductor chips, said method comprising:

identifying resource costs for manufacturing said wafer including identifying equipment costs;

computing load factors for each of said resource costs, said computing load factors for said equipment costs comprising determining a number of exposure fields on said wafer, computing a raw processing time for said wafer based on said number of exposure fields, and determining a percentage said raw processing time represents of a manufacturing time period on an equipment element, said equipment element having said equipment costs;

producing weighted resource costs based on said resource costs and said load factors, said producing weighted resource costs for said equipment costs comprising multiplying said equipment costs by said percentage;

summing said weighted resource costs for said wafer;

determining a volume of said wafer manufactured; and

dividing said weighted resource costs by said volume to produce a weighted cost per wafer.

2. The method in claim 1, wherein said identifying equipment costs comprises:

assigning costs of one or more of depreciation, spare parts, operator staffing, maintenance support, and vendor service contracts to said equipment element; and

rolling up costs of related peripheral equipment to said equipment element.

3. The method in claim 1, wherein computing load factors for said equipment costs further comprises allocating indirect equipment costs, including at least one of power, deionized water, bulk chemical usage, air filtration, air purification, hoods, transfer equipment, air showers, minienvironments, gas-isolation boxes and other peripheral equipment to said equipment element.

4. The method in claim 1, wherein:

said identifying resource costs includes determining optional process costs; and

said computing load factors includes computing load factors for at least one optional process based on a volume of said wafers subjected to said optional process.

5. The method in claim 1, wherein said determining a volume of said wafer manufactured comprises substituting a predetermined full capacity volume for said volume of said wafer manufactured.

6. The method in claim 1, wherein said determining a volume of said wafer manufactured comprises subtracting an amount of rework and scrap from said volume of said wafer manufactured.

7. The method as an claim 1, further comprising verifying said weighted cost per wafer.

8. The method in claim 1, wherein said identifying resource costs further comprises:

identifying partnumber costs;

identifying technology costs; and

identifying factory costs.

9. The method in claim 8, wherein said computing load factors for said partnumber costs comprises allocating a portion of costs of one or more of yield analysis, systems setup, mask-set qualification, process tailoring, raw materials and engineering activities to said wafer based on an age of said wafer.

10. The method in claim 8, wherein said computing load factors for said technology costs comprises allocating a portion of costs of one or more of process qualification, routing creation, recipe creation, process window definition, design of process controls and yield planning to said wafer based on an age of said wafer.

11. The method in claim 8, wherein said computing load factors for said factory costs comprises allocating a portion of costs of one or more of administrative services, data processing, garment rooms, break areas and systems support to said wafer.

12. A computer system for causally relating costs to a wafer having semiconductor chips, said method comprising:

a unit for identifying resource costs for manufacturing said wafer including a unit for identifying equipment costs;

a unit for computing load factors for each of said resource costs, said unit for computing load factors for said equipment costs comprising a unit for determining a number of exposure fields on said wafer, a unit for computing a raw processing time for said wafer based on said number of exposure fields, and a unit for determining a percentage said raw processing time represents of a manufacturing time period on an equipment element, said equipment element having said equipment costs;

a unit for producing weighted resource costs based on said resource costs and said load factors, said unit for producing weighted resource costs for said equipment costs comprising a unit for multiplying said equipment costs by said percentage;

a unit for summing said weighted resource costs for said wafer;

a unit for determining a volume of said wafer manufactured; and

a unit for dividing said weighted resource costs by said volume to produce a weighted cost per wafer.

13. The computer system in claim 12, wherein said unit for identifying equipment costs comprises:

a unit for assigning costs of one or more of depreciation, spare parts, operator staffing, maintenance support, and vendor service contracts to said equipment element; and

a unit for rolling up costs of related peripheral equipment to said equipment element.

14. The computer system in claim 12, wherein said unit for computing load factors for said equipment costs further comprises a unit for allocating indirect equipment costs, including at least one of power, deionized water, bulk chemical usage, air filtration, air purification, hoods, transfer equipment, air showers, minienvironments, gas-isolation boxes and other peripheral equipment to said equipment element.

15. The computer system in claim 12, wherein:

said unit for identifying resource costs includes a unit for determining optional process costs; and

said unit for computing load factors includes a unit for computing load factors for at least one optional process based on a volume of said wafers subjected to said optional process.

16. The method in claim 12, wherein said unit for determining a volume of said wafer manufactured comprises a unit for substituting a predetermined full capacity volume for said volume of said wafer manufactured.

17. The computer system in claim 12, wherein said unit for determining a volume of said wafer manufactured comprises a unit for subtracting an amount of rework and scrap from said volume of said wafer manufactured.

18. The computer system as an claim 12, further comprising a unit for verifying said weighted cost per wafer.

19. The computer system in claim 12, wherein said unit for identifying resource costs further comprises:

a unit for identifying partnumber costs;

a unit for identifying technology costs; and

a unit for identifying factory costs.

20. The computer system in claim 19, wherein said unit for computing load factors for said partnumber costs comprises a unit for allocating a portion of costs of one or more of yield analysis, systems setup, mask-set qualification, process tailoring, raw materials and engineering activities to said wafer based on an age of said wafer.

21. The computer system in claim 19, wherein said unit for computing load factors for said technology costs comprises a unit for allocating a portion of costs of one or more of process qualification, routing creation, recipe creation, process window definition, design of process controls and yield planning to said wafer based on an age of said wafer.

22. The computer system in claim 19, wherein said unit for computing load factors for said factory costs comprises a unit for allocating a portion of costs of one or more of administrative services, data processing, garment rooms, break areas and systems support to said wafer.

23. A computer program product comprising a program storage device readable by a computer system tangibly embodying a program of instructions executed by said computer system to perform in a process for causally relating costs to a wafer having semiconductor chips, said process comprising:

identifying resource costs for manufacturing said wafer including identifying equipment costs;

computing load factors for each of said resource costs, said computing load factors for said equipment costs comprising determining a number of exposure fields on said wafer, computing a raw processing time for said wafer based on said number of exposure fields, and determining a percentage said raw processing time represents of a manufacturing time period on an equipment element, said equipment element having said equipment costs;

producing weighted resource costs based on said resource costs and said load factors, said producing weighted resource costs for said equipment costs comprising multiplying said equipment costs by said percentage;

summing said weighted resource costs for said wafer;

determining a volume of said wafer manufactured; and

dividing said weighted resource costs by said volume to produce a weighted cost per wafer.

24. The computer program product in claim 23, wherein said identifying equipment costs comprises:

assigning costs of one or more of depreciation, spare parts, operator staffing, maintenance support, and vendor service contracts to said equipment element; and

rolling up costs of related peripheral equipment to said equipment element.

25. The computer program product in claim 23, wherein computing load factors for said equipment costs further comprises allocating indirect equipment costs, including at least one of power, deionized water, bulk chemical usage, air filtration, air purification, hoods, transfer equipment, air showers, minienvironments, gas-isolation boxes and other peripheral equipment to said equipment element.

26. The computer program product in claim 23, wherein:

said identifying resource costs includes determining optional process costs; and

said computing load factors includes computing load factors for at least one optional process based on a volume of said wafers subjected to said optional process.

27. The computer program product in claim 23, wherein said determining a volume of said wafer manufactured comprises substituting a predetermined full capacity volume for said volume of said wafer manufactured.

28. The computer program product in claim 23, wherein said determining a volume of said wafer manufactured comprises subtracting an amount of rework and scrap from said volume of said wafer manufactured.

29. The computer product program as an claim 23, further comprising verifying said weighted cost per wafer.

30. The computer program product in claim 23, wherein said identifying resource costs further comprises:

identifying partnumber costs;

identifying technology costs; and

identifying factory costs.

31. The computer program product in claim 30, wherein said computing load factors for said partnumber costs comprises allocating a portion of costs of one or more of yield analysis, systems setup, mask-set qualification, process tailoring, raw materials and engineering activities to said wafer based on an age of said wafer.

32. The computer program product in claim 30, wherein said computing load factors for said technology costs comprises allocating a portion of costs of one or more of process qualification, routing creation, recipe creation, process window definition, design of process controls and yield planning to said wafer based on an age of said wafer.

33. The computer program product in claim 30, wherein said computing load factors for said factory costs comprises allocating a portion of costs of one or more of administrative services, data processing, garment rooms, break areas and systems support to said wafer.