The SEMATECH Cost of Ownership Model Mike Berman U of Arizona

AGENDA n Why use it? n How to use it? n What if? u CoO of a new system u Process 1 Vs Process 2 u Quality Improvement Tool n Summary

Purpose: n “The SEMATECH Cost of Ownership (SCoO) model was developed to address the economic and productive performance of a tool while operating in pre-production or in production.”

Description: n “The SCoO model is a calculator to perform a cost comparison of options for completing a step in a semiconductor wafer fabrication process”

Why is the SCoO so important? n Manufacturing cost control is critical to survival in the market place. n For cost control you must: u Know the cost of each step u Understand the reasons for these costs u Control and reduce the costs n ASP’s drop each year, So must costs!!!

Why use the SEMATECH Model? n Independent of OEM & the Supplier n Developed by SEMATECH n It is the De Facto standard n It permits “Apple’s to Apple’s comparisons

Cost of Ownership Calculation

The SEMATECH Model is NOT n A MEASURE OF THE PROCESS u If the new process does not work or u Has a lower yield, do not waste your time n ABSOLUTE n Able to make tools smaller!

Model Description n The Model is very comprehensive n Up to 90 inputs & 210 output parameters n Can be used with as few as 10 inputs & 1 output n Once understood it produces simple and fast results n The Rewards are enormous: High benefit to effort ratio Detailed insight into the cost makeup of each step “What if” type questions can be addressed n The SCoO is most useful as a comparison tool.

Dos & Do Nots: n “improve” n Do not “improve” the technique used to find the values n n Do “add spreadsheets within the spreadsheet” u u See next page for examples

Examples n For sputter Target cost per wafer: u Target Life, Target cost, Avg. process dep n Cost of gas per wafer (Etch/CVD): u Volume & cost of tank u Usage, flow and time (all steps) n Cmp u Pad cost, life(in polish mins or wafers)

Major parts of the Model: n Title: Fill in more detail than you will need! u In 1 year they will all look the same! n n VOLUME/THROUGHPUT DATA n n EQUIPMENT DATA n n PRODUCTION/RUNNING DATA (usage) n n MAINTENANCE COSTS n n PERSONNEL PER SYSTEM /STANDARD RATES n n ANNUAL COST PER GOOD WAFER ($) n n MANAGEMENT SUMMARY PHOTO LITHOGRAPHY WORK SHEET

E10-90 Equipment States Stacking Chart

Title: Fill in more detail than you will need!

VOLUME/THROUGHPUT DATA

EQUIPMENT DATA

PRODUCTION/RUNNING DATA (usage)

MAINTENANCE COSTS

PERSONNEL PER SYSTEM / STANDARD RATES

The “Must” have lines (only 7)

The more you use, the better it is!

How to use the SCoO It’s in Excel-not PowerPoint!

Standard Rates n Burdened Salary u Engineer$115,000 u Supervision$100,000 u Operator$30./Hr u Maintenance$35./Hr n Administrative Rates u Insurance0.47 % u Personal Prop. Tax1.34 % u Interest10.0 % u Inflation Rate 3.0 % u Life of Equipment5 years u Test Wafer Cost$80.00 n Value of incoming $100 to $1400 n Value of completed$1,500.

Output (line 525)

Output (line 357/382)

SURPRISES !! n Capital cost of the equipment may not be the driver for Cost of Ownership n MTBF (>75 hr.) impact on utilization & cost reduction is not as significant as previously thought n Defect density & Line Yield are far more important then previously anticipated n The cost of the wafer at the process step is more important than previously considered

Defect Density n Die area (Line 104)1 cm2 n Probability of a failure (Line 105) 16.6% n Defect Density (Line 21) Vs Cost of Wafer.01 (defects/cm2)$ $ $ $ $ $154.64

CoO Scrap ($) Calculation

CoO of a “New System” n Use your “best” numbers n Be fair n Use a run rate of Max. (for most models) n This is NOT a measure of the Process n This is only an n This is only an estimate, your real cost may vary

Process 1 Vs Process 2 n Be Fair n Throughput & Defect Density are the main Drivers. n Use “real” numbers, not specs n If you do not have “Real” Defect Density Data, use “0”.

Quality Improvement Tool n Major use of the Model n Only change key cells n Changes in “Throughput” need changes in “Production requirements” n This can be used for “small changes”

How do I get my copy? n SEMATECH stopped support on n Now it is call “ TWO COOL” from Wright, Williams, & Kelly u Dublin Boulevard, Suite D262 u Dublin, CA u n Cost $7, (in 1995)

SUMMARY n You now know more than most users n Use it, work with it n Split your screen, place line 382 at the top of your screen, and make changes and see how they change the total CoO.