this talk will explain definition of exposure parameter setting up an exposure details on exposure...
Post on 06-Jan-2018
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This talk will explain
• definition of exposure parameter
• setting up an exposure
• details on exposure parameter
RAITH uses• Round beam with Gaussian-shaped profile• moved along line = name vector scan
step sizetime @ point = dwell time
write field
Writing strategyWriting strategy
number of electrons beam current dwell time= Tdwell Ibeam
2dwellbeam
sTI Dose Area
Unit is µAs/cm²
area step size2
= s2
Rule: To clear an area a certain number of electronshave to hit the sample within a certain area= clearing area dose
s
s
Area exposure - DoseArea exposure - Dose
sTI Dose Line dwellbeam
Unit is pAs/cm
Rule: To clear an line a certain number of electronshave to hit the sample within a certain length= clearing line dose
number of electrons beam current dwell time= Tdwell Ibeam
line step size= s
s
Line exposure - DoseLine exposure - Dose
dwellbeam TI DoseDot Unit is pAs
Rule: To clear an line a certain number of electronshave to hit the sample within a certain point= clearing dot dose
number of electrons beam current dwell time= Tdwell Ibeam
Dot exposure - DoseDot exposure - Dose
beam currentdefined by column, i.e. filament, aperture, voltage, ...
dosedefined by process, i.e. resist, developer, temperature, ...
dwell time and step sizeexposure parameters defined by your needs, e.g.accuracy, GDSII, throughput, ...
Exposure parametersExposure parameters
Parameter Area Line Dotbeam current yes yes yesdose yes yes yesdwell time yes yes yesstep size yes yes no
selectable 3 3 2determined 1 1 1under the condition to clear or equivalently fulfillthe dose equation.
Exposure parametersExposure parameters
Central window to set upall exposure parameters calculated
step size anddwel time
Calculator usingclearing dose andbeam current
Software – Exposure moduleSoftware – Exposure module
Window to perform calculation
beam current and dosestart calculation
Software – CalculatorSoftware – Calculator
Pull design intopositionlist withDrag and Drop
Software – ExposureSoftware – Exposure
Right mouse clickthen open properties
Software – PositionlistSoftware – Positionlist
calculatedparametersas inExposuremodule
choose to expand dialog
Software – PositionlistSoftware – Positionlist
to use parametersfrom Exposure moduleplace tick
Software – PositionlistSoftware – Positionlist
to use individual parameters, removeticks and pressCalculator
Software – PositionlistSoftware – Positionlist
dwell time at eachposition can be re-scaled using dosefactor
Software – PositionlistSoftware – Positionlist
opens dialog toset theseparameters
• Loops
• Line mode
• Meander mode
• Settling time
• Flyback time
• Circular mode
Software – Exposure DetailsSoftware – Exposure Details
• Loops
• Exposure raster
• Line/Meander
• Scan direction
• Settling time
• Flyback time
• Circular mode
Software – Exposure DetailsSoftware – Exposure Details
Each write field isrepeated n times.
(0 means infinitenumber of loops)
Exposure Details - LoopsExposure Details - Loops
Fixed sets basic step size to 2.0 nm
Free allows selection of basic step size for betterplacement accuracy
Exposure Details - RasterExposure Details - Raster
Line mode = element isfilled with each line fromthe same direction.
Meander mode = elementis filled with each line fromthe opposite direction.
See talk “Exposure parameters” for hints whichmode to use.
Exposure Details – Area ModeExposure Details – Area Mode
In Automatic mode,the beam is scanned
along the sideof greatest length
In Manual mode, you can select the direction of the that the beam is scanned
Exposure Details – Scan directionExposure Details – Scan direction
Settling time = waitingperiod at beginning ofeach element
Flyback time = waitingperiod between lines.
Please note, in our softwareFlyback time = settling time flyback factor
Exposure Details – Settling/Flyback timeExposure Details – Settling/Flyback time
Circular mode =• round elements are decomposed
into dots• dots are exposed in centric rings• vertices are not used
Exposure parameters =• Uses area parameters
Exposure Details – Circular modeExposure Details – Circular mode
Exposure Details – Dynamic compensationExposure Details – Dynamic compensation
Addresses theissue of thenominal and physical positionof the beam duringan exposure with respect to the sample surface
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