DILBERTDILBERT

• Did research and learned about several communication Did research and learned about several communication devices – cellular phones, Bluetooth/Wi-Fi, and RFID devices – cellular phones, Bluetooth/Wi-Fi, and RFID • Received silicon wafer to be used as base for antennas – Received silicon wafer to be used as base for antennas – could use other substrates if equipment was availablecould use other substrates if equipment was available• Received a traveler defining the steps necessary to Received a traveler defining the steps necessary to fabricate your antennafabricate your antenna•Cleaned silicon wafers to provide a contamination free Cleaned silicon wafers to provide a contamination free surfacesurface• Grew SiOGrew SiO22 (silicon dioxide) to provide an insulating (silicon dioxide) to provide an insulating dielectric surface dielectric surface • Determined your application, either cellular, Bluetooth/Wi-Determined your application, either cellular, Bluetooth/Wi-Fi, or RFIDFi, or RFID• Determined how to find the correct length for the antenna Determined how to find the correct length for the antenna based on the applicationbased on the application• Using a decision matrix determined the conductor to be Using a decision matrix determined the conductor to be used to fabricate the antennaused to fabricate the antenna• This week will deposit conductor of choiceThis week will deposit conductor of choice

Summary of Project to DateSummary of Project to Date

Thin Film DepositionThin Film Deposition

Conductors are deposited using a Conductors are deposited using a vacuum chambervacuum chamber

The vacuum chamber reduces the The vacuum chamber reduces the atmosphere to high vacuum levels (no atmosphere to high vacuum levels (no atmosphere)atmosphere)

This reduces contaminating the films, This reduces contaminating the films, provides a non-contaminating provides a non-contaminating environment free of oxygen, water environment free of oxygen, water vapor, etc. and allows materials to vapor, etc. and allows materials to melt at lower temperatures.melt at lower temperatures.

Thin Film DepositionThin Film Deposition

Thin film deposition tools are very Thin film deposition tools are very complex due to the need to create complex due to the need to create high vacuum levels.high vacuum levels.

Vacuum levels of 5x10Vacuum levels of 5x10-7-7 torr and torr and better are typical. Sea level better are typical. Sea level atmospheric pressure is about 740 atmospheric pressure is about 740 torr or 7.4x10torr or 7.4x102 2

Because of their complexity, vacuum Because of their complexity, vacuum chambers are very expensive. chambers are very expensive.

Thin Film DepositionThin Film Deposition To achieve high vacuum levels, several types of To achieve high vacuum levels, several types of

vacuum pumps are used.vacuum pumps are used.1.1. Mid level vacuum levels (2x10Mid level vacuum levels (2x10-3-3 torr) are reached with torr) are reached with

rotary vane vacuum pumps. These pumps are also rotary vane vacuum pumps. These pumps are also know as mechanical or roughing vacuum pumpsknow as mechanical or roughing vacuum pumps

2.2. High level vacuum levels are reached usingHigh level vacuum levels are reached using Diffusion vacuum pumps – requires liquid nitrogen to Diffusion vacuum pumps – requires liquid nitrogen to

prevent oil contaminationprevent oil contamination Turbomolecular pumps – like a small jet engine, clean Turbomolecular pumps – like a small jet engine, clean

and fast, good for processes that require the introduction and fast, good for processes that require the introduction of a process gas. Because of the high speed vanes, of a process gas. Because of the high speed vanes, subject to catastrophic failuresubject to catastrophic failure

Cryogenic vacuum pumps – uses low temperature (10Cryogenic vacuum pumps – uses low temperature (10ooK) K) – also clean and fast pumping but requires regeneration – also clean and fast pumping but requires regeneration periodically which is time consumingperiodically which is time consuming

Thin film deposition tools in the ECE Thin film deposition tools in the ECE Microelectronics Clean RoomMicroelectronics Clean Room

CVC 601-sputter deposition

Varian 3125 e-beam deposition

CHA Mark 50 e-beam deposition

Cooke-thermal deposition

Conductor DepositionConductor Deposition The Cooke thermal evaporator is not The Cooke thermal evaporator is not

currently used.currently used. The CVC sputter tool is used only for The CVC sputter tool is used only for

aluminum depositions. Only an aluminum aluminum depositions. Only an aluminum target is available.target is available.

The Varian 3125 and CHA Mark 50 e-beam The Varian 3125 and CHA Mark 50 e-beam deposition tools are used for all other deposition tools are used for all other conductors, Cu, Au, Ag, Cr, Ni conductors, Cu, Au, Ag, Cr, Ni – An e-beam evaporates material, it get the An e-beam evaporates material, it get the

material so hot it becomes a gas and material so hot it becomes a gas and evaporates. It then travels in a straight line, evaporates. It then travels in a straight line, because it is under vacuum, until it condenses because it is under vacuum, until it condenses when it strikes a colder surfacewhen it strikes a colder surface

With sputtering, an Argon plasma is formed, With sputtering, an Argon plasma is formed, causing argon ions to strike a metal target causing argon ions to strike a metal target

and knock loose material. Because an and knock loose material. Because an electric field is created, material is deposited electric field is created, material is deposited

on the substrateon the substrate

Material target

Argon plasma – ionized argon in an electric field

Substrate to be coated

E-beam Evaporation uses a high energy electron beam to vaporize (change from a solid to vapor)

materials, especially metals

Overall view of the Varian 3125 Overall view of the Varian 3125 vacuum chamber. This tool vacuum chamber. This tool

deposits thin films using e-beam deposits thin films using e-beam evaporationevaporation

Portion of Varian 3125 control Portion of Varian 3125 control rackrack

Varian 3125 quartz heater controller, Varian 3125 quartz heater controller, shutter controller and planetary shutter controller and planetary

rotation controllerrotation controller

Planetary (wafer holder) rotation controller

Quartz heater

controller

E-beam shutter

controller

Electron beam power supplyElectron beam power supply

Typically 6-8KV are required to form the

electron beam

Electron beam can be steered by

magnetic fields

Cryopump temperature-must be

below 15oK

Varian 3125 ion gauge Varian 3125 ion gauge controller and deposition controller and deposition

controllercontroller

Ion Gauge controller Deposition controller

Varian 3125 view of open Varian 3125 view of open chamberchamber

Wafer planetary – can rotate or stay stationary. Can be

removed for loading

Varian 3125 4-pocket e-beam Varian 3125 4-pocket e-beam cruciblecrucible

With an e-beam (electron beam) evaporator With an e-beam (electron beam) evaporator the material is heated to a vapor (gas) and the material is heated to a vapor (gas) and

then condenses on cooler surfacesthen condenses on cooler surfaces

Molten material hot enough to vaporize (become a gas)

Electron beam is

formed and strikes the

metal crucible

Substrates (wafers) sit at the top of the

chamber

Varian 3125 wafer planetaryVarian 3125 wafer planetary

Wafer planetary for Varian 3125

Varian 3125 Varian 3125

Wafers are held down by spring clips

Varian 3126 Quartz HeatersVarian 3126 Quartz Heaters

Varian 3125 door showing Varian 3125 door showing glasds slide holderglasds slide holder

Glass slide must be replaced before each run

Overall view of the CHA Mark 50 Overall view of the CHA Mark 50 vacuum chamber. This tool vacuum chamber. This tool

deposits thin films using e-beam deposits thin films using e-beam evaporationevaporation

Inside of CHA Mark 50 chamber Inside of CHA Mark 50 chamber showing wafer platen – can not showing wafer platen – can not be removed from the chamberbe removed from the chamber

CHA Mark 50 wafer adapter CHA Mark 50 wafer adapter ringring

Adapter rings are available for 2”, 3” and 4” wafers

Adapter ring for 4”/100mm

wafer

CHA Mark 50 4-pocket e-beam CHA Mark 50 4-pocket e-beam cruciblecrucible

Four different materials are available to do

sequential evaporations

CHA Mark 50 crucible materials CHA Mark 50 crucible materials and chamber temperature and chamber temperature

monitormonitor

Materials currently inside the 4 pocket crucible are shown with their pocket

number

Pocket is chosen using this indexer

CHA Mark 50 crystal oscillators for CHA Mark 50 crystal oscillators for evaporation material thickness evaporation material thickness

measurementmeasurement

Crystal oscillators

New glass slides must be used for each evaporation

CHA Mark 50 cryo-pump CHA Mark 50 cryo-pump controlcontrol

Cryogenic pump temperature – should be less than 15oK

CHA Mark 50 vacuum gauge CHA Mark 50 vacuum gauge controllercontroller

Vacuum chamber pressure of 7.5 x 10-7 torr

CHA Mark 50 E-beam power CHA Mark 50 E-beam power supply and controllersupply and controller

Power supply is interlocked to prevent activation if vacuum pressure, cooling

water, and zero current conditions are not met

Power supply main on/off switch

High voltage switch

and current control

E-beam evaporationE-beam evaporation

Crucible being heated by an electron beam

Overall view of the CVC vacuum Overall view of the CVC vacuum chamber. This tool deposits thin chamber. This tool deposits thin

films using “sputtering”films using “sputtering”

CVC sputter tool with chamber CVC sputter tool with chamber lid openlid open

Wafers are loaded into

position

Looking into the CVC sputter tool Looking into the CVC sputter tool chamber, showing the 8” aluminum chamber, showing the 8” aluminum

targettarget

CVC sputter tool control CVC sputter tool control racksracks

Ion gauge

Cryo pump temperature – must be below 16oK

Argon MFC – 30 sccm flow typical

CVC sputter tool DC power CVC sputter tool DC power supply for aluminum targetsupply for aluminum target

DC Voltage about 4KVDC current 0.5 to 1.0 A

CVC sputter tool view portCVC sputter tool view port

View of argon sputter plasma View of argon sputter plasma in CVC sputter toolin CVC sputter tool

View of argon plasma in AJA View of argon plasma in AJA sputter toolsputter tool

Sputter target

Shutter

Substrate (wafer) stage

Wafer stage can rotate and heat

Homework AssignmentHomework AssignmentDue next class meetingDue next class meeting

Review “Mask design steps” from web siteReview “Mask design steps” from web site Read “Designing Antennas for Cellular Telephones” from web Read “Designing Antennas for Cellular Telephones” from web

site.site. Find “AutoCad” on Mosaic – listed under Mechanical Find “AutoCad” on Mosaic – listed under Mechanical

Engineering as AutoCad 2006Engineering as AutoCad 2006 Become familiar with AutoCad. There is a tutorial on my web Become familiar with AutoCad. There is a tutorial on my web

sitesite Begin preliminary dimension sketches for your antenna designBegin preliminary dimension sketches for your antenna design

Maximum size 20mmx20mm Maximum size 20mmx20mm Minimum size 5mmx5mmMinimum size 5mmx5mm Line width – 1mm Line width – 1mm Spacing between lines – 1mm or greaterSpacing between lines – 1mm or greater No sharp cornersNo sharp corners Must be able to fit inside a box to allow cutting into individual antennaMust be able to fit inside a box to allow cutting into individual antenna Length must match your design lengthLength must match your design length Can be any design – be creativeCan be any design – be creative

Dimension drawing of your design is requiredDimension drawing of your design is required

Simple spiral designSimple spiral design

Cingular Logo designCingular Logo design

XBOX design XBOX design Note-DO NOT USE WHITE ON Note-DO NOT USE WHITE ON

BLACBACKGROUNDBLACBACKGROUND

Football Design- DO NOT USE WHITE ON Football Design- DO NOT USE WHITE ON DARK BACKGROUNDDARK BACKGROUND

UNC-Charlotte Crown designUNC-Charlotte Crown design

Dimensions not in a contrasting Dimensions not in a contrasting colorcolor