IBM 8: Spin CoatingIBM 8: Spin Coating

Greg BurttGreg BurttGreg HewittGreg Hewitt

David ValenteDavid ValenteContact Engineer: Kevin RemillardContact Engineer: Kevin Remillard

Faculty Mentor: Jeff MarshallFaculty Mentor: Jeff Marshall

Original Cleaning DiskOriginal Cleaning Disk

Bowl SetBowl Set

Final Design OverviewFinal Design Overview

Solution 1: Modify the Cleaning DiskSolution 1: Modify the Cleaning Disk It has been determined through mathematical It has been determined through mathematical

analysis and a physical inspection that the current analysis and a physical inspection that the current cleaning disk has design flawscleaning disk has design flaws

These include but may not be limited to the following:These include but may not be limited to the following: Collection area for solvent is wide and flat, it appears that a Collection area for solvent is wide and flat, it appears that a

significant portion does not flow through the disksignificant portion does not flow through the disk A large majority of solvent sprays only horizontally, causing the A large majority of solvent sprays only horizontally, causing the

bowl set to collect resist above and below this levelbowl set to collect resist above and below this level The exit area for solvent is too small, an appreciable amount of The exit area for solvent is too small, an appreciable amount of

solvent appears to overflow out of the cleaning disksolvent appears to overflow out of the cleaning disk

Solution 2: Coat the Bowl SetSolution 2: Coat the Bowl Set If the bowl set were to have a coating that defied the If the bowl set were to have a coating that defied the

buildup of resist, or was readily expurgated, it would buildup of resist, or was readily expurgated, it would aid the cleaning process and compliment Solution 1aid the cleaning process and compliment Solution 1

Explanation of the SolutionsExplanation of the Solutions

Solution 1Solution 1 A preliminary prototype cleaning disk has been decided upon A preliminary prototype cleaning disk has been decided upon

through the use of a Pugh chartthrough the use of a Pugh chartThis prototype increases solvent flow to the entire bowl setThis prototype increases solvent flow to the entire bowl set

Above the horizontal, at the horizontal, below the horizontal, and the Above the horizontal, at the horizontal, below the horizontal, and the bottom bowl, around the knife edgebottom bowl, around the knife edge

The solvent exit velocity (and therefore mass flow rate) has been The solvent exit velocity (and therefore mass flow rate) has been increased through the use of parabolic channels that will increase increased through the use of parabolic channels that will increase the height of fluid in the spinning diskthe height of fluid in the spinning diskA radius at the point of impact of the solvent on the disk will cause A radius at the point of impact of the solvent on the disk will cause more solvent to be collected and less to splash back off, a smaller more solvent to be collected and less to splash back off, a smaller opening will also be employed to catch as much spray as possibleopening will also be employed to catch as much spray as possible

Solution 2Solution 2 The company The company makes a coating called tt-Kote makes a coating called tt-Kote

specifically designed for this application, we plan to apply it to a specifically designed for this application, we plan to apply it to a second set of bowls.second set of bowls.

Pugh Chart for Disk DesignPugh Chart for Disk Design

Prototype DiskPrototype Disk

Testing and Refining the Solutions:Testing and Refining the Solutions:Part 1Part 1

A test stand will be built to replicate the equipment A test stand will be built to replicate the equipment used at IBMused at IBM This will consist, in part, of an acrylic glass caseThis will consist, in part, of an acrylic glass case

Inside the case there will be a motor to spin the cleaning disk, Inside the case there will be a motor to spin the cleaning disk, and to spin a wafer when performing tests to better determine and to spin a wafer when performing tests to better determine where resist builds up on the bowlswhere resist builds up on the bowls

There will be gravity fed nozzles to spray the solvent into the There will be gravity fed nozzles to spray the solvent into the cleaning disk from the back sidecleaning disk from the back side

A set of bowls will also be contained within, but will be A set of bowls will also be contained within, but will be removableremovable

A blower will be connected to the bowl sets to create the A blower will be connected to the bowl sets to create the correct airflowcorrect airflow

Test StandTest Stand

Testing and Refining the Solutions:Testing and Refining the Solutions:Part 2Part 2

After creation of the test stand, a number of tests After creation of the test stand, a number of tests will be performedwill be performed The current cleaning disk will be tested to compare The current cleaning disk will be tested to compare

with the calculations, as a check of their accuracywith the calculations, as a check of their accuracy Simulated photoresist (magenta inkjet printer ink) will Simulated photoresist (magenta inkjet printer ink) will

be applied to the bowl sets, both coated and be applied to the bowl sets, both coated and uncoated, using a spinning plastic disk in place of a uncoated, using a spinning plastic disk in place of a silicon wafersilicon wafer

This allows for an appropriate characterization of where This allows for an appropriate characterization of where resist builds upresist builds up

The prototype cleaning disk design will then be The prototype cleaning disk design will then be modified based on the results and an actual prototype modified based on the results and an actual prototype will be manufactured for testingwill be manufactured for testing

Testing and Refining the Solutions:Testing and Refining the Solutions:Part 3Part 3

Both cleaning disks will be tested in both Both cleaning disks will be tested in both sets of bowls to determine two thingssets of bowls to determine two things If the prototype performs as expected, or what If the prototype performs as expected, or what

needs to be modifiedneeds to be modified If the coated bowl outperforms the uncoated If the coated bowl outperforms the uncoated

bowlbowlDetermine if the performance increase outweighs Determine if the performance increase outweighs the cost of the coatingthe cost of the coating

Refine the prototype design and repeatRefine the prototype design and repeat

Pert ChartPert ChartReceive

Parts01/14

AssembleTest Stand

01/21

Ship Bowl forCoating01/21

ReceiveCoatedBowl set

04/01

TestCurrent

CleaningDisk

02/04

RefinePrototype

Design02/08

ManufacturePrototype

02/22

CoatedBowl/DiskTesting

Results04/30

ReturnOn

Investment12/21

This can be postponed if necessary

Bowl/DiskTesting03/07

Final Testing04/09

ManufactureFinal

Prototype04/01

—————— Critical PathCritical Path

- - - - - Non-Crucial Path:- - - - - Non-Crucial Path:

Can be postponed if coated bowl set arrives lateCan be postponed if coated bowl set arrives late

Work Breakdown Task ListWork Breakdown Task List

Task Member(s) Involved Dates Estimated Hours Cost Deliverables

Return on Investment GB, GH, DV 12/07- 12/21 4 $0.00 ROI Spreadsheet

Part Receiving and Inventory GB 01/14-01/21 2 $1,650.00 Inventory Database

Test Stand Assembly GB, GH, DV 01/14-01/21 10 $50.00 Test Stand

Ship bowl for Coating GH, Kevin 01/14-??? 0.5 $800.00 Coated Bowl

Write Test Plan GH 01/14-01/21 4 $0.00 Test Plan

Characterizing Original Disk* GB, GH, DV 01/21-02/04 10 $0.00 Baseline Dataset

Refine Initial Prototype Disks GB, GH, DV 01/21-02/08 5 $0.00 Prototype Disk Design

Manufacturing Prototype DV 02/08-02/22 5 $200.00 Prototype Disk

Modify Test Plan GB, GH, DV 02/08-02/22 1 $0.00 Prototype Test Plan

Prototype Disk & Bowl Testing* GB, GH, DV 02/22-03/07 10 $0.00 Prototype Dataset

Refine Prototype Design GB, GH, DV 02/22-03/07 5 $0.00 Final Prototype Design

Manufacturing Final Prototype DV 03/07-04/01 5 $200.00 Final Prototype Disk

Final Testing* GB, GH, DV 04/01-04/09 10 $0.00 Final Dataset

Results Processing GB, GH, DV 04/01-04/30 20 $0.00 Final Results

91.5 $2,900.00

*Coated bowl data included if received within timeframe.

CharterCharter

By April 30th, 2008 a final cleaning disk prototype, By April 30th, 2008 a final cleaning disk prototype, cleaning recipe, and bowl coating decision will be made cleaning recipe, and bowl coating decision will be made that will reduce the frequency with which the bowls are that will reduce the frequency with which the bowls are removed for cleaning. Initial testing will be performed to removed for cleaning. Initial testing will be performed to observe cleaning solvent behavior and collect empirical observe cleaning solvent behavior and collect empirical data on the performance of the current cleaning disk, data on the performance of the current cleaning disk, and compare performance of the current bowl with a and compare performance of the current bowl with a bowl coated with Nx-Edge tt-Kote. After initial testing, the bowl coated with Nx-Edge tt-Kote. After initial testing, the disk design will be refined and a prototype will be disk design will be refined and a prototype will be manufactured and tested in both the coated and manufactured and tested in both the coated and uncoated bowlsets. Modifications and testing will uncoated bowlsets. Modifications and testing will continue to be performed on the prototype disk until a continue to be performed on the prototype disk until a satisfactory final design is engineered. The results of the satisfactory final design is engineered. The results of the testing, the final cleaning disk design, cleaning recipe, testing, the final cleaning disk design, cleaning recipe, and bowl coating decision will be submitted to IBM. and bowl coating decision will be submitted to IBM.