Photolithography Lesson

8/12/2019 Photolithography Lesson

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Introduction: This lesson has been designed to take (3) 60 minuteclass periods. Students will learn about photolithography by creatingtheir own circuit board, as well as learn about electrical resistance andusing this inormation to graph mathematical data.

California State Science Standards Addressed in Project

Physical Sciences: Grade 8! (a): Students know reactant atoms and molecules interact to ormproducts with di"erent chemical properties! (e): Students know how to determine whether a solution is acidic,basic, or neutral

Grade 8: Investigation and Experimentation# (a): $lan and conduct a scienti%c in&estigation to test a hypothesis# (b): '&aluate the accuracy and reproducibility o data# (c): istinguish between &ariable and controlled parameters in a test# (d): ecogni*e the slope o the linear graph as the constant in therelationship y+k and apply this principle in interpreting graphsconstructed rom data.# (e): -onstruct appropriate graphs rom data and de&elop uantitati&estatements about the relationships between &ariables.# (): /pply simple mathematical relationships to determine a missinguantity in a mathematical epression, gi&en the two remaining terms(including speed+ distancetime, density+ mass&olume, orce+pressure area, &olume+ area height)# (g): istinguish between linear and nonlinear relationships on agraph o data.

OjectivesStudents will be able to

e%ne photolithography and discuss its rele&ance tonanomanuacturing and real world application

escribe the process o photolithography through a series osteps 'plain the importance o a circuit board in technological

products 'plain the concept o resistance and its mathematical ormula

1llustrate the concept o resistance through a linear graph

Preparation

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-oordinate collaborati&e groups2 students should be arranged ina heterogeneous mi (academic le&el and gender)2 pair studentswho ha&e not worked with each other in a group setting

ake copies o all worksheets

Set up classroom conduci&e or group work group stations

Set up teacher demonstration area Set up materials area or students

4a&e digital camera on hand to take impromptu photos ostudents

Classroom Expectations

Students will listen and be respectul o teacheracilitator at alltimes

Students will not distract others with side con&ersations

Students will keep their work area neat and organi*ed, disposing

o all trash Students will listen and respect each team member5s ideas whenworking in a group

!aterials for "esson #:$hoto mask ( pair or each student) $hoto resist de&eloper( bottle or each group)$re7cut -ircuit board ( each student2 teacher) Stripperapplicator ( bottle or each group)-ircuit board alignment sheet ( or each group) $aper towels8lass slides uler ( per group)

8lo&es ( pair or each student) 'tch71n7/79ag it ( pergroup)Sharpies ( or each group) $encils ( or each student)Stopwatch ( or each group) $ost 1t ;otes -hart $aper

< beakers (per group) Scissors (i necessary)Sink with hot and cold7water =ater oleculemodels>itmus paperSmall en&elope or circuit board ( or each student)?oam balls

>abelsigital camera

!aterials for "esson $:-ircuit boardsultimeter@&ersi*ed graph paper-olored markers

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$encilsigital camera

Grade Level: A Subject(s):Science'ngineering Strategy:Teacher7irected

Multiple Intelligence(s): Bisual, Berbal, inesthetic, 1nterpersonal

Bloom's Taonomy: nowledge, -omprehension, /nalysis

!ali"ornia Standard "or t#e Teac#ing $ro"ession: 'ngaging andsupporting all students in learning

Introd%ction&Opening Activity/ppro Time: C0 D 30 minutes

Students will be asked i they know what a circuit board is andwhat it is used or2 wait and listen or students to gi&ethoughtsideas

/ter student responses, students should be told that they willlearn all about circuit boards and photolithography

'plain to students that they will work in collaborati&e groups orthe remainder o the lesson

e&eal to students the members o each group and pro&ide themwith a designated area in the classroom

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'plain to students they must choose a team name as well asdecide what role each team member will ul%ll2 there will be !members to a team

>ist the roles a&ailable within each team:7 'posure -aptain: in charge o the EB 'posure Station

and collects all materials or this particular part o theeperiment7 'tchant -aptain: in charge o the 'tchant Station and

collects all materials or this particular part o theeperiment

7 e&eloping -aptain: in charge o the de&eloping processand collects all materials or this particular part o theeperiment

7 'tching -aptain: in charge o the 'tching procedure andcollects all materials or this particular part o theeperiment

7 $hoto resist -aptain: in charge o stripping the photo resistand collects all materials or this particular part o theeperiment

'plain to each captain that they are responsible or the groupmembers conducting e&ery step o the eperiment during theirparticular segment

Students will be asked to assemble into assigned groups:7 Students will choose team name and roles and report this

inormation to the teacher @nce all groups are established, students will be asked to list 0

e&eryday products that circuit boards are ound in and draw anillustration o what they belie&e a circuit board looks like2 teachermust pass out post it note chart paper or students to completethis acti&ity

Students will be gi&en ! minutes to complete this task2 a grouprepresentati&e rom each group will report their answers to theentire class

Teacher will pro&ide positi&e eedback

!ethodology(Teaching)/ppro Time: 0 minutes

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Glass Slides (* "or eac# group)Gloves (& pair "or eac# student) so t#eir +ngerprints do not get

on t#e p#oto mas% or t#e substrate and to protect "romeposure to c#emicals,

S#arpies (to -rite name on bac% o" t#e circuit board)Stop-atc# ( eposure "or & minutes)

Teacher should ha&e minimal light in the classroom i possibleand inorm students not to begin until instructed to do so

. 'ach student should ha&e a pre7cut photo maskC. Students should place their %rst and last initials o their name

on the back o a pre7cut circuit board3. Students should put on glo&es and peel o" the black tape

rom their circuit boards to re&eal the photo resist (substrate).emind students not to touch the photo resist


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Teacher and students will prepare the etchant material

(he etchant captain from each gro%p needs to get thefollo'ing items from the materials area:

.tc#/In/0/Bag 1itLabels

bea%ers per group (& "or -ater2 & "or etc#ant)3ot -ater

Instructions "or .tc#ant Station

. @pen your etch7in7a7bag bo and remo&e the plastic bag with thepellets inside

C. @pen the plastic bag by sliding open the rod and clip system

3. $our C!0 m> o hot water into plastic bag containing the pelletsabel your beakers ( or water, or etchant)H. $our the etchant into the beaker labeled etchantA. $lace the two beakers in a sae location or later#. -lose your bag and place the bag aside: @ ;@T T4@= 1T

/=/IJ0. Students should return back to their EB 'posure Station

Independent Practice: Students should answer Kuestion on their >ab Lournal

=orksheet

!odeling/ppro Time: 0 minutes

Teacher and students will re&iew what occurred at the EB'posure Station

Teacher and students will obser&e the circuit board and gi&ereasons why the eposed photo resist has a yellow color, while

the uneposed photo resist has a sil&er color. Teacher willeplain eposed &ersus uneposed

1norm students that they can now answer Kuestion C on their>ab Lournal =orksheet

G%ided Practice/ppro Time: 0 minutes

Teacher and students will conduct the de&eloper procedure

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(he developing captain from each gro%p needs to get thefollo'ing items from the materials area:

$#oto resist developer bea%ers

Label (& cold -ater2 & developer)

Instructions "or 4eveloping $rocess

. >abel each beaker ( cold water2 photo resist de&eloper)C. Students should put on glo&es and remo&e the glass slides

rom the photo mask and get their circuit board3. Take the photo resist de&eloper bottle and pour its contents

into the beaker labeled photo resist de&eloper


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7 1ron chloride (?e->3) molecules in the etchant interactswith copper (-u) metal to oidi*e the copper

7 @idation: the loss o an electron7 This is important because the oidi*ed copper can be

remo&ed by water. This eplains the concept o solubility(the amount o a solution that will dissol&e in a speci%csol&ent under gi&en conditions)

Teacher will ask students i they know what the chemical ormulaor water is2 wait or responses2 encourage students to take aneducated guess i they are unsure

'plain that 4C@ means that one molecule o water is composedo C 4ydrogen atoms (4C) and @ygen atom (@)

Show students model o one molecule o water: (8rey: @ygenatom 7777 Iellow: 4ydrogen atoms)

'plain to students that water is mostly 4C@, howe&er in anyaueous (water) solution there are some other combinations ohydrogen and oygen Goating around. These other twocombinations that are Goating around are called 4ydroide (@4 7)

and 4ydronium (43@M) 'plain to students that the number o hydroide and hydronium

molecules will determine whether a solution is acidic, neutral, or

base 4a&e < plastic clear cups a&ailable: 4ydroide will be

represented by blue oam balls2 4ydronium will be representedby red oam balls

7 stcup (represents water): %lled with water molecules7 Cndcup (represents the concept o acidic): %lled with water

molecules and a lot o hydronium7 3rdcup (represents the concept o neutral): %lled with water

molecules and the same number o hydroide andhydronium

7


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7 / neutral solution will turn the blue or red litmus paperpurple

Independent Practice/ppro Time: ! minutes

Students can measure the p4 actor o the de&eloper, etchant,and water and determine whether they are neutral, acidic, orbase. Students will record their answers on the >ab eport=orksheet. Students can answer Kuestions 3,


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ea&e an opening o at least two inches(about the length o your thumb) since the neutrali*ationreaction releases gas

!. Slowly remo&e the rod and clip that separates the neutrali*errom the etchant

6. nead the miture by pressing the etchant solution andneutrali*er together

H. The miture will oam and rise2 please make sure that you donot spill the miture out o the bag

A. @nce the rising o the miture has subsided, place bag asidein an upright position. The miture will become solid in a ewhours

)i*erentiated "earning Activities (>earning centers,manipulati&es, special needs, etc.)

8ate: 1n addition to the lesson students can research the earliest circuitboard created-hallenged: Student would be responsible or knowing what a circuitboard is, what one looks like, and what products it can be ound in4andicapped: The student will be placed at the teacher demonstrationarea and assisted by the teacher in each eperimental step'>>: Bocabulary terms and concepts will be reinorced through picturesand diagrams

AssessmentStudents will be epected to ha&e participated in the eperiment anddiscussion and to complete =orksheets and C and the >ab eportworksheet. /ll worksheets will be turned in to the teacher and theollowing points can be assigned to each worksheet or all worksheetscombined.

Score ?inal $roduct< =orksheet has *ero spelling

errors, neatly done, ideas andthoughts are well organi*ed.3 =orksheet has *ero spelling

errors, neatly done2 ideas andthoughts are not organi*ed.

C =orksheet contains some spellingerrors, not so neatly done, ideasand thoughts are not organi*ed.

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=orksheet contains numerousspelling errors2 messy work, ideasand thoughts are not organi*ed.

State PToday we learned about photolithography by creating our owncircuit boardQ8i&e students en&elopes and instruct them to write their names ontheir en&elopes and place their circuit boards inside.

.nd o" Lesson

Grade Level: A Subject(s):Science'ngineering Strategy:Teacher7irected

Multiple Intelligence (s): Bisual, Berbal, inesthetic, 1nterpersonal

Bloom's Taonomy: nowledge, -omprehension, /pplication,'&aluation

Introd%ction&Opening Activity/ppro Time: ! minutes Teacher can begin today5s lesson by asking a ew uestions rom

the pre&ious lesson (use below or create your own):7 =ho can tell me the our layers o the circuit boardR7 =hat are the parts o a photo maskR7 ;ame at least one station in our pre&ious lesson. =hat was

it used orR7 ;ame at least ! products circuit boards are ound in.

Teacher will return graded worksheets rom >esson to students2lead students into acti&ity planned or today5s lesson.

Students will return back to work groups they were placed in>esson .

Teacher will pass out student en&elopes with circuit boards.

Teacher will re&iew the classroom epectations ound in >esson.

Inp%t

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/ppro Time: C! minutesTeacher will lecture about photolithography process by eplaining theollowing concepts:

ultimeter: an instrument designed to measure electric current,&oltage, and usually resistance

Show students a digital multimeter ultimeters are designed or electronics engineers and its usage2

can be abbre&iated as or digital multimeter Terms: (raw an eample on whiteboard i necessary to enhance

understanding)7 'lectric current: the Gow o electricity, or eample,

through a wire7 Boltage: the orce pushing the electric current through the

wire7 esistance: a measure o how hard it is to orce electric

current through a wire

'plain water analogy:7 The Gow o water through a pipe is common with the Gow

o electrons in a wire7 =ater Gow in a pipe is measured by the amount o water

that Gows past a point7 'lectrical Gow in a wire is measured by the amount o

charge that Gows past a point Show students the serpentine patterns o copper and the contact

pads on the circuit board Show students the narrow strip and wide strip on circuit board

'ach group should be gi&en a multimeter

'plain to students that they will measure resistance betweencontact pads using the multimeter and graph this inormation

'plain to students how to measure the resistance between thecontact pads on the circuit board through demonstration

7 Take the black wire and place it on the %rst contact pad2then place the red wire on the second contact pad

7 ead the ultimeter or the results2 the results are gi&en inohms

7 epeat this process by keeping the black wire on the %rstcontact pad and mo&ing the red wire to the third contact

pad7 epeat, mo&ing the red wire to the ourth contact pad

1norm students that they will enter their measurement &alues onthe 4ypothesisesistance ata worksheet

ake a graph and show students what inormation will be on the7ais and the y7ais

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/ter obtaining their data they will make a graph like theollowing:

(I7ais)esistance

(7ais)>ength

1norm students that they will plot both the thin and thick wire onthe same graph

1norm students that they will need to %nd the slope o the linesor the thin and thick wire

Independent Practice

/ppro Time: C! minutes Students will complete 4ypothesisesistance ata =orksheet

with the ollowing uestions:7 =hich part o the circuit board will ha&e a higher

resistance: the one with wide wires or narrow wiresR7 oes resistance increase or decrease with the length and

width o the wireR Students will measure resistance between contact pads and C,

and 3, and and < or the wide and narrow wires Students will make a plot o resistance as a unction o the length

o the copper line or the thin wire and then again or the thickwire (on the same graph)

Inp%t/ppro Time:

'plain to students the electrical resisti&ity ormula

'plain to students that they will sol&e or

'plain to students the concept o direct &ariation:

7 The ormula or direct &ariation is y + k, where k is theconstant o &ariation. @ne &ariable directly a"ects theother.

To urther eplain the concept, use the ollowing eample:The weekly salary e&in earns, S, &aries directly as the numbero hours, h, which he works. 'press this relationship as aormula:

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OR S = hk !he"e # $% &he 'o(%&a(&) ?or the purposes o our proOect is y2 > is 2 k is /

Show students how to %nd the slope o a line using the gi&eninormation:7 8i&en two points (, y) and (C, yC) the ormula or the slope o

a straight line going through these two points is:

+ (yCD y)(CD ) Students should %nd the slope rom their data

Teacher will gi&e students data to calculate cross sectional area,/+ width height

'plain to students that /+ cross sectional area is now a known

uantity, students will need to %nd the missing uantity romthe relationship k+ /

Students will also be gi&en the length o the wire

Teacher will instruct students to work with thick wire %rst

Independent Practice/ppro Time: ! minutes

Students will complete the 'lectrical esistance ?ormulaworksheet

)i*erentiated "earning Activities (>earning centers,manipulati&es, special needs, etc.)8ate: Students can recogni*e that the line does not cross the point oorigin using y+ mMb-hallenged: Students can plot the points o each contact pad outcome4andicapped: Students should be placed with teacher or directassistance'>>: ?lash cards can be created to reinorce learning2 de%nition on oneside, illustration on the backside or the ollowing terms: multimeter,circuit board, slope, 7ais, I7ais, graph

AssessmentStudents will be epected to ha&e participated in the eperiment,discussion, and complete the 4ypothesisesistance ata worksheet./ll worksheets will be turned in to the teacher and the ollowing pointscan be assigned to the worksheet. Students should also turn in theirgraphs ater the student representati&e presentation.

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7or%s#eet 8ubricScore ?inal $roduct

< =orksheet has *erospellingnumerical errors, neatlydone2 ideas and thoughts are wellorgani*ed.

3 =orksheet has *erospellingnumerical errors, neatlydone2 ideas and thoughts are notorgani*ed.

C =orksheet contains somespellingnumerical errors, not soneatly done2 ideas and thoughtsare not organi*ed.

=orksheet contains numerousspellingnumerical errors2 messywork, ideas and thoughts are notorgani*ed.

Grap# 8ubricScore ?inal $roduct

< 8raph is complete with correct&alues, neatly done, wellorgani*ed

3 8raph is complete with correct&alues, neatly done, not soorgani*ed

C 8raph has incorrect &alues,plotting errors, not neat, notorgani*ed

8raph has numerous incorrect&alues, plotting errors, not neat,

not organi*ed

Clos%re&C%lminating Activity/ppro Time: C! minutes

Student representati&e rom each group will report student%ndings as a whole or the group.

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Take digital pictures o student with circuit board and graphs

$resent students with a certi%cate o participation

Take group photo: principal, teacher, acilitator, grad students,students

Treat or the class or participating and ehibiting great beha&ior

'nd o lesson

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Documents

Photolithography Lesson